WO2018134769A1

WO2018134769A1 - Methods of forming polymer compositions

Info

Publication number: WO2018134769A1
Application number: PCT/IB2018/050326
Authority: WO
Inventors: Yanwu ZHOU; Johannes Gerardus Petrus GOOSSENS
Original assignee: Sabic Global Technologies B.V.
Priority date: 2017-01-18
Filing date: 2018-01-18
Publication date: 2018-07-26

Abstract

Solid-state methods for preparing polymer compositions by combining a polyol component, a polyester component, and a transesterification catalyst are described, as well as polymer compositions prepared according to the described methods.

Description

METHODS OF FORMING POLYMER COMPOSITIONS

BACKGROUND

[0001] Polyesters (such as poly(alkylene terephthalates) are useful engineering thermoplastics, as their comparatively high crystallization rate makes them particularly suitable for injection molding and other applications. At the same time, although poly(alkylene terephthalates) are suitable for some applications, they in some cases have limited dimensional stability, thermal resistance, mechanical resistance, and environmental resistance as compared to cross-linked thermosets. Accordingly, improved poly(alkylene terephthalates) and methods of making them, are needed.

SUMMARY

[0002] The above-described long-felt needs and other deficiencies of the art are met by the methods of the disclosure. In one aspect, the present disclosure provides methods of forming a polymer composition by solid-state modification, comprising: with a solid solution that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; reacting and heating the polyol component and the polyester component at a temperature between about the Tm and the Tg of the polyester component so as to form cross-links among the polymer chains so as to give rise to a pre -dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition that comprises amorphous and crystalline polyester regions.

[0003] Also provided are methods of forming a polymer composition by solid-state modification, comprising: with a solution that comprises: a polyol component that comprises an amount of one or more polyols, a polyester component, and a transesterification catalyst, forming, from the solution, a solid that comprises an amount of the polyester in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the solid at a temperature between the Tg and Tm of the at least partially crystalline polyester so as to form a pre-dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition.

[0004] Further disclosed are dynamically cross-linked network polymer compositions, comprising: a polyester that comprises a plurality of crystalline regions bound to amorphous regions, at least some of the amorphous regions being cross-linked by cross-links that comprise a reacted polyol component.

[0005] Also provided are compositions, comprising: in solid form, an at least partially crystalline polyester in particulate form, a polyol comprising at least three hydroxyl groups, and a transesterification catalyst.

[0006] Further disclosed are compositions, comprising: a dynamically cross-linked copolymer that comprises repeat units of (a) a polyester and (b) the reaction product of a polyol reacted with the polyester.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The summary, as well as the following detailed description, is further understood when read in conjunction with the appended drawings. For the purpose of illustrating the technology, there are shown in the drawings exemplary and preferred embodiments of the invention; however, the disclosure is not limited to the specific methods, compositions, and devices disclosed. In addition, the drawings are not necessarily drawn to scale. In the drawings:

[0008] FIG. 1 provides a depiction of an exemplary process by which polymer particles formed by the disclosed technology are fixed in position by glass beads and then contacted with a flow (upwards arrow) of gas, e.g., nitrogen gas.

[0009] FIG. 2 provides DMTA curves of cured embodiments of the disclosure that are a PBT-glycerol polymer composition (2.4 mol% Cr(acac)3) and PBT-glycerol polymer composition (2.5 mol% Ti(OBu)4 catalyst) as compared to neat PBT195. The heating rate was 3 °C/min, and the oscillating frequency was 1 Hz.

[0010] FIG. 3 A provides storage (G'; open symbols) and loss (G"; filled symbols) moduli of PBT/Glycerol compositions with and without 2.5 mol% Ti(OBu)4 catalyst versus frequency at 270 °C by 25 mm plate-plate geometry with 1% strain applied; FIG. 3B provides storage (G' ; open symbols) and loss (G"; filled symbols) moduli of PBT/Glycerol compositions with Cr(III)(acac)3 catalyst versus frequency at 240, 270 and 300 °C by 25 mm plate-plate geometry with 1% strain applied; and FIG. 3C provides an Arrhenius plot of characteristic relaxation times of PBT/Glycerol compositions with Cr(III)(acac)3 catalyst (obtained from data in FIG. 3B) versus inverse temperature.

[0011] FIG. 4A provides the development of molecular weight Mw and dispersity as a function of extrusion time (^extrusion) in the presence of zinc acetylacetonate (Zn(acac)2) with and without pentaerythritol. FIG. 4B provides the development of Mw as a function of ssp time (&p) in the presence of zinc acetylacetonate with pentaerythritol.

[0012] FIG. 5A provides the development of the Mw as a function of tssp in the presence of zinc stearate (upper triangle), zinc acetate (circle), zinc acetylacetonate (down triangle) and zinc oxide (square) with pentaerythritol. The catalyst content was constant at 0.2 mol% concerning the PBT repeat units. FIG. 5B provides the development of the dispersity as a function of tssp in the presence of zinc stearate (upper triangle), zinc acetate (circle), zinc acetylacetonate (down triangle) and zinc oxide (square) with pentaerythritol. The catalyst content was constant at 0.2 mol% concerning the PBT repeat units.

[0013] FIG. 6A provides the storage modulus of PBT and PBT/PEY-based copolymers catalyzed with 0.2 mol% Zn2+, heating is at 3 °C min^_1 and frequency of 1 Hz. FIG. 6B provides DSC curves of PBT/PEY-based vitrimers after solid-state (co)polymerization. All the samples containing 2.4 mol% pentaerythritol.

[0014] FIG. 7A provides elastic (open symbols) and viscous (filled symbols) moduli versus frequency at 250 °C with 1% strain for the PBT/PEY-based vitrimer catalyzed by zinc salts with different ligands. FIG. 7B provides complex viscosity versus frequency at 250 °C with 1% strain for the PBT/PEY-based vitrimer catalyzed by zinc salts with different ligands.

[0015] FIG. 8 presents Table 2, an overview of PBT/Gly copolyesters prepared by SSM before gelation.

[0016] FIG. 9 provides the chemical structure of the PBnPolyolmT copolymers obtained by SSM of PBT with BPO comonomer.

[0017] FIG. 10A. provides SEC traces representing changes of the molecular weight of (PB90.9BPO9.iT^{0 2(Zn)}) copolyester during the SSM as a function of tssm; FIG. 10B provides the development of M_n and PDI as a function of tssm; FIG. 10C provides ¾ NMR spectra of the copolyester PB87BPO13 T° ^2(Zn) before and after SSM reaction recorded in CDCb/HFIP at room temperature; and FIG. 10D provides development of T_m, T_c and degree of crystallinity (χ) as a function of tssm measured by DSC at a heating rate of 10 °C/min from -50 to 250 °C, first heating run data were used.

[0018] FIG. 11A provides DMTA curves showing the storage modulus of PBT/BPO copolyesters prepared by SSM and neat PBT195, heating at 3 °C/min and an oscillating frequency of 1 Hz: and FIG. 1 IB for PBnBPOmT copolyesters of varying composition; and FIG. 1 IB provides the foregoing before and after TFA deprotection.

[0019] FIG. 12 provides a proposed mechanism for debenzalation and cross-linking.

[0020] FIG. 13A provides normalized stress relaxation data at different temperatures for PB90.9BDO9.1T copolyesters with 0.2 mol% Zn(acac)2 before deprotection and FIG. 13B provides the foregoing after deprotection. [0021] FIG. 14. provides Arrhenius plots showing the relationship between characteristic relaxation time and viscosity of PB90.9BDO9.1T copolyester and the corresponding dynamic network as obtained from data analysis of the stress relaxation experiments of FIG. 13.

[0022] FIG. 15A provides an evolution of the molecular weight distribution during prepolymerization and SSM of PB86.sGlyi3.2T^2(Zn) PBT/Gly copolyester; and FIG. 15B provides expanded regions (3.75-6.35 ppm) of the ¾ NMR spectra before and after prepolymerization: (1) PB₈₅.4Glyi4.6T^2(Zn) physical mixture; (2) branched PGlyT; (3) PB₈6.8Glyi3.2T^2(Zn) at &m = 1 h; (4) PB96.oGly₄.oT^2(Zn) at fem = 7 h; and PB₉7.8Gly2.2T^2(Zn) at fem = 7

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0023] Described herein are processes for preparing polymer compositions. These processes comprise, in some embodiments, combining a polyol component, a polyester component, and a transesterification catalyst at a temperature of from about 140 °C to about 200 °C in the absence of solvent. Polymer compositions prepared according to these methods are also described. The disclosure is also directed to molded articles prepared from the polymer compositions of the disclosure. The present disclosure may be understood more readily by reference to the following detailed description of desired embodiments and the examples included herein. In the following specifications and the claims that follow, reference will be made to a number of terms which have the following meanings.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present disclosure. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0025] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. As used in the specification and in the claims, the term "comprising" may include the embodiments "consisting of and "consisting essentially of." The terms "comprise(s)," "include(s)," "having," "has," "can," "contain(s)," and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named ingredients/steps and permit the presence of other ingredients/steps. However, such description should be construed as also describing compositions or processes as "consisting of and "consisting essentially of the enumerated ingredients/steps, which allows the presence of only the named ingredients/steps, along with any impurities that might result therefrom, and excludes other ingredients/steps.

[0026] Numerical values in the specification and claims of this application, particularly as they relate to polymers or polymer compositions, reflect average values for a composition that may contain individual polymers of different characteristics. Furthermore, unless indicated to the contrary, the numerical values should be understood to include numerical values which are the same when reduced to the same number of significant figures and numerical values which differ from the stated value by less than the experimental error of conventional measurement technique of the type described in the present application to determine the value.

[0027] All ranges disclosed herein are inclusive of the recited endpoint and independently combinable (for example, the range of "from 2 grams to 10 grams" is inclusive of the endpoints, 2 grams and 10 grams, and all the intermediate values). The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value; they are sufficiently imprecise to include values approximating these ranges and/or values. Ranges can be expressed herein as from one value (first value) to another value (second value). When such a range is expressed, the range includes in some aspects one or both of the first value and the second value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as "about" that particular value in addition to the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0028] As used herein, approximating language may be applied to modify any quantitative representation that may vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about" and "substantially," may not be limited to the precise value specified, in some cases. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. The modifier "about" should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression "from about 2 to about 4" also discloses the range "from 2 to 4." The term "about" may refer to plus or minus 10% of the indicated number. For example, "about 10%" may indicate a range of 9% to 11%, and "about 1" may mean from 0.9-1.1. Other meanings of "about" may be apparent from the context, such as rounding off, so, for example "about 1" may also mean from 0.5 to 1.4.

[0029] As used herein, the terms "about" and "at or about" mean that the amount or value in question can be the designated value, approximately the designated value, or about the same as the designated value. It is generally understood, as used herein, that it is the nominal value indicated ±10% variation unless otherwise indicated or inferred. The term is intended to convey that similar values promote equivalent results or effects recited in the claims. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is "about" or "approximate" whether or not expressly stated to be such. It is understood that where "about" is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0030] The present disclosure is directed to methods of preparing polymer

compositions by combining a polyol component, a polyester component, and a transesterification catalyst. The polymer compositions prepared according to the described methods can be "dynamic cross-linked polymer compositions." "Dynamic cross-linked polymer compositions" have dynamically, covalently cross-linked polymer networks. At low temperatures, dynamic cross-linked polymer compositions behave like classic thermosets, but at elevated temperatures, it is believed that the cross-links undergo transesterification reactions. At those elevated temperatures, the transesterification happens at such a rate that flow-like behavior is observed and the material can be processed. Hence, the polymer can be processed much like a viscoelastic thermoplastic. At lower temperatures, these dynamic cross-linked polymer compositions behave more like classical thermosets. As the rate of inter-chain transesterification slows down, the network becomes more rigid. The dynamic nature of their cross-links allows these polymers to be heated, reheated, and reformed, as the polymers maintain structural integrity under demanding conditions.

[0031] A pre-dynamic cross-linked polymer composition may be cured to arrive at the final state of being a dynamic cross-linked polymer composition; and a pre-dynamic cross-linked composition when subjected to a curing process may (a) exhibit a plateau modulus of from about 0.01 MPa to about 1000 MPa when measured by dynamic mechanical analysis at a temperature above a melting temperature of the polyester of the pre-dynamic cross-linked composition and (b) exhibit a capability of relaxing internal residual stresses at a characteristic timescale of between 0.1 and 100,000 seconds above a glass transition temperature of the polyester, as measured by stress relaxation rheology measurement.

[0032] As used herein, a "polyol component" is an organic compound having at least two -OH residues, preferably, three or four -OH residues. Exemplary polyol components include, e.g., glycerol, trimethylolpropane (TMP), and pentaerythritol. As used herein, a "polyester component" is a polymer that has ester linkages, i.e., polyesters. The polymer can be a polyester, which contains only ester linkages between monomers. The polymer can also be a copolyester, which is a copolymer containing ester linkages and other linkages as well.

[0033] The polymer having ester linkages can be a polyalkylene terephthalate, for example, poly(butylene terephthalate), also known as PBT. PBT may have a weight average molecular weight of up to 100,000. The polymer having ester linkages can be poly(ethylene terephthalate), also known as PET. PET may a weight average molecular weight of up to 100,000.

[0034] The polymer having ester linkages can be PCTG, which refers to

poly(cyclohexylenedimethylene terephthalate), glycol-modified. This is a copolymer formed from 1,4-cyclohexanedimethanol (CHDM), ethylene glycol, and terephthalic acid. The two diols react with the diacid to form a copolyester. The resulting copolyester has the structure shown belo

where p is the molar percentage of repeating units derived from CHDM, q is the molar percentage of repeating units derived from ethylene glycol, and p>q, and the polymer may have a weight average molecular weight of up to 100,000.

[0035] The polymer having ester linkages can also be PETG. PETG has the same structure as PCTG, except that the ethylene glycol is 50 mol% or more of the diol content. PETG is an abbreviation for poly(ethylene terephthalate), glycol-modified.

[0036] The polymer having ester linkages can be poly(l,4-cyclohexane-dimethanol- 1,4-cyclohexanedicarboxylate), i.e. PCCD, which is a polyester formed from the reaction of CHDM with dimethyl cture shown below:

where n is the degree of polymerization, and can be as high as 1,000, and the polymer may have a weight average molecular weight of up to 100,000.

[0037] The polymer having ester linkages can be poly(ethylene naphthalate), also known as PEN, which has the structure shown below:

[0038] The polymer having ester linkages can also be a copolyestercarbonate. A copolyestercarbonate contains two sets of repeating units, one having carbonate linkages and the other having ester link

where p is the molar percentage of repeating units having carbonate linkages, q is the molar percentage of repeating units having ester linkages, and p+q=100%; and R, R', and D are independently divalent radicals.

[0039] As additional examples, the repeating unit having ester linkages could be butylene terephthalate, ethylene terephthalate, PCCD, or ethylene naphthalate as depicted above.

[0040] Aliphatic polyesters can also be used in the disclosure. Examples of aliphatic polyesters include polyesters having repeating units of the following formula:

O O

— — R— O— C II R¹— C II-)— where at least one R or R¹ is an alkyl-containing radical. They are prepared from the polycondensation of glycol and aliphatic dicarboxylic acids.

[0041] As used herein, a "transesterification catalyst" catalyzes the reactions of the disclosure. The transesterification catalyst is used in an amount up to about 25 mol%, for example, 0.025 mol% to 25 mol%, of the total molar amount of ester groups in the polyester component. In some embodiments, the transesterification catalyst is used in an amount of from 0.025 mol% to 10 mol% or from 1 mol% to less than 5 mol%. Preferred embodiments include 0.025, 0.05, 0.1, 0.2 mol% of catalyst, based on the number of ester groups in the polyester component. Alternatively, the catalyst is used in an amount of from 0.1% to 10% by mass relative to the total mass of the reaction mixture, and preferably from 0.5% to 5%.

[0042] Transesterification catalysts are known in the art and are usually chosen from metal salts, for example, acetylacetonates, of zinc, tin, magnesium, cobalt, calcium, titanium, and zirconium. Rare earth salts of alkali metals and alkaline earth metals, particularly rare earth acetates, alkali metal and alkaline earth metals such as calcium acetate, zinc acetate, tin acetate, cobalt acetate, nickel acetate, lead acetate, lithium acetate, manganese acetate, sodium acetate, and cerium acetate are other catalysts that can be used in the disclosure. Salts of saturated or unsaturated fatty acids and metals, alkali metals, alkaline earth and rare earth metals, for example zinc stearate, are also envisioned as suitable catalysts.

[0043] Other catalysts that can be used in the disclosure include metal oxides such as zinc oxide, antimony oxide, and indium oxide; metal alkoxides such as titanium tetrabutoxide, titanium propoxide, titanium isopropoxide, titanium ethoxide, zirconium alkoxides, niobium alkoxides, tantalum alkoxides; alkali metals; alkaline earth metals, rare earth alcoholates and metal hydroxides, for example sodium alcoholate, sodium methoxide, potassium alkoxide, and lithium alkoxide; sulfonic acids such as sulfuric acid, methane sulfonic acid, paratoluene sulfonic acid; phosphines such as triphenylphosphine, dimethylphenylphosphine,

methyldiphenylphosphine, triterbutylphosphine; and phosphazenes.

[0044] The catalyst may also be an organic compound, such as benzyldimethylamide or benzyltrimethylammonium chloride. These catalysts are generally in solid form, and advantageously in the form of a finely divided powder. One preferred catalyst is

zinc(II)acetylacetonate. Suitable transesterification catalysts are also described in Otera, J. Chem. Rev. 1993, 93, 1449-1470. Tests for determining whether a catalyst will be appropriate for a given polymer system within the scope of the disclosure are described in, for example, U.S. Published Application No. 2011/0319524 and WO 2014/086974. [0045] The transesterification catalyst used in the methods of the disclosure may include one or more catalysts. In some embodiments, the transesterification catalyst is zinc(II)acetylacetonate. In other embodiments, the transesterification catalyst is

chromium(III)acetylacetonate. In still other embodiments, the transesterification catalyst is titanium(IV)(OBu)4. In some embodiments, the transesterification catalyst is a mixture of zinc(II)acetylacetonate, chromium(III)acetylacetonate, and titanium(IV)(OBu)4.

[0046] One or more of the catalysts used in the methods of the invention may be added as a separate component of the reaction mixture. In other embodiments, one or more of the catalysts may be inherently present in the polyester component as a residual catalyst from the polyester polymerization process. In some embodiments, the polyol component, the polyester component, and the transesterification catalyst are combined in the presence of some amount of solvent so as to facilitate the component combination. Following the combination, some or all of the solvent may be removed, e.g., by increased temperature, reduced pressure, or a combination of both. The reaction mixture may, in some embodiments, comprise between 0 and 5 wt% of an organic or polyfluorinated solvent. In some embodiments, the reaction mixture comprises about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or about 5 wt% of an organic or polyfluorinated solvent;

perfluorinated solvents are considered especially suitable. In some embodiments, the polyol component, the polyester component, and the transesterification catalyst are combined free of any solvent.

[0047] In some embodiments, the polyol component, the polyester component, and the transesterification catalyst are combined in an inert atmosphere, i.e., an atmosphere having less than atmospheric levels of oxygen. In some embodiments, the inert atmosphere contains less than 5 vol% of oxygen. For example, the polyol component, the polyester component, and the transesterification catalyst can be combined in the presence of a nitrogen or argon atmosphere.

[0048] The reaction mixture comprising the polyol component, the polyester component, and the transesterification catalyst can be heated to a temperature of, e.g., from about 140 °C to about 200 °C to produce the polymer composition of the disclosure, depending on the polymers involved. For example, the combination of the polyol component, the polyester component, and the transesterification catalyst can be heated to a temperature of about 140, 150, 160, 170, 180, 190, or about 200 °C. In preferred embodiments, the combination of the polyol component, the polyester component, and the transesterification catalyst is heated to between about 160 °C and about 180 °C. In some embodiments, a combination may be subjected to two or more temperatures. As one example, the polyol, polyester, and catalyst may be combined at a first temperature, and then subjected to a second (higher) temperature. In some embodiments, it is useful to use a temperature that avoids evaporation of volatile species, e.g., a comonomer. The higher temperature may be used to facilitate removal of any volatile species (e.g., alcohols) that may be evolved by the reaction of the polyol, polyester, and transesterification catalyst.

[0049] The mixture comprising the polyol component, the polyester component, and the transesterification catalyst can be heated for a time sufficient to form the polymer composition. In some embodiments, the mixture can be heated for between about 15 minutes and about 24 hours. For example, the mixture can be heated for about 15 minutes, 30 minutes, 45 minutes, 60 minutes, 90 minutes, or 120 minutes. In other embodiments, the mixture can be heated for about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or about 24 hours to produce the polymer compositions of the disclosure.

[0050] Exemplary polymer compositions prepared according to the described methods can include about 45 to about 80 or even 95 mol% of the polyester component, for example about 45, 50, 55, 60, 65, 70, 75, or about 80 mol% of the polyester component. Exemplary polymer compositions prepared according to the described methods can include about 10 to about 45 mol% of the polyol component, for example, about 10, 15, 20, 25, 30, 35, 40, or about 45 mol% of the polyol component. Exemplary polymer compositions prepared according to the described methods can include about 0.025 to about 30 mol% of the transesterification catalyst, for example 0.025, 0.05, 0.075, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or about 30 mol% of the transesterification catalyst. The combined mole percentage values of all the components used in the methods of the disclosure does not exceed about 100 mol%.

[0051] The polymer compositions produced according to the described methods can be isolated and/or purified using conventional techniques. For example, after the polymer composition is formed, it can be cooled to ambient temperature and discharged from the reaction vessel. It can also be dried, preferably under reduced pressure. The polymer compositions produced according to the described methods can be formed into any form suitable for use in the art.

[0052] The polymer compositions of the disclosure may also comprises additives, as desired. Exemplary additives include: one or more polymers, ultraviolet agents, ultraviolet stabilizers, heat stabilizers, antistatic agents, anti-microbial agents, anti-drip agents, radiation stabilizers, pigments, dyes, fibers, fillers, plasticizers, fibers, flame retardants, antioxidants, lubricants, wood, glass, and metals, and combinations thereof.

[0053] Exemplary polymers that can be mixed with the compositions of the disclosure include elastomers, thermoplastics, thermoplastic elastomers, and impact additives. The compositions of the disclosure may be mixed with other polymers such as a polyester, a polyestercarbonate, a bisphenol-A homopolycarbonate, a polycarbonate copolymer, a tetrabromo-bisphenol A polycarbonate copolymer, a polysiloxane-co-bisphenol-A

polycarbonate, a polyesteramide, a polyimide, a polyetherimide, a polyamideimide, a polyether, a polyethersulfone, a polyepoxide, a polylactide, a polylactic acid (PLA), an acrylic polymer, polyacrylonitrile, a polystyrene, a polyolefin, a polysiloxane, a polyurethane, a polyamide, a polyamideimide, a polysulfone, a polyphenylene ether, a polyphenylene sulfide, a polyether ketone, a polyether ether ketone, an acrylonitrile-butadiene-styrene (ABS) resin, an acrylic - styrene-acrylonitrile (ASA) resin, a polyphenylsulfone, a poly(alkenylaromatic) polymer, a polybutadiene, a polyacetal, a polycarbonate, an ethylene-vinyl acetate copolymer, a polyvinyl acetate, a liquid crystal polymer, an ethylene -tetrafluoroethylene copolymer, an aromatic polyester, a polyvinyl fluoride, a polyvinylidene fluoride, a polyvinylidene chloride, tetrafluoroethylene, or any combination thereof.

[0054] The additional polymer can be an impact modifier, if desired. Suitable impact modifiers may be high molecular weight elastomeric materials derived from olefins, monovinyl aromatic monomers, acrylic and methacrylic acids and their ester derivatives, as well as conjugated dienes that are fully or partially hydrogenated. The elastomeric materials can be in the form of homopolymers or copolymers, including random, block, radial block, graft, and core- shell copolymers.

[0055] One specific type of impact modifier is an elastomer-modified graft copolymer comprising (i) an elastomeric (i.e., rubbery) polymer substrate having a T_g less than about 10 °C, less than about 0 °C, less than about -10 °C, or between about -40 °C to -80 °C, and (ii) a rigid polymer grafted to the elastomeric polymer substrate. Materials suitable for use as the elastomeric phase include, for example, conjugated diene rubbers, for example polybutadiene and polyisoprene; copolymers of a conjugated diene with less than about 50 wt% of a copolymerizable monomer, for example a monovinylic compound such as styrene, acrylonitrile, n-butyl acrylate, or ethyl acrylate; olefin rubbers such as ethylene propylene copolymers (EPR) or ethylene-propylene-diene monomer rubbers (EPDM); ethylene-vinyl acetate rubbers; silicone rubbers; elastomeric Ci-Cs alkyl(meth)acrylates; elastomeric copolymers of Ci-Cs alkyl(meth)acrylates with butadiene and/or styrene; or combinations comprising at least one of the foregoing elastomers. Materials suitable for use as the rigid phase include, for example, mono vinyl aromatic monomers such as styrene and alpha-methyl styrene, and monovinylic monomers such as acrylonitrile, acrylic acid, methacrylic acid, and the C1-C6 esters of acrylic acid and methacrylic acid, specifically methyl methacrylate.

[0056] Specific impact modifiers include styrene -butadiene -styrene (SBS), styrene- butadiene rubber (SBR), styrene-ethylene-butadiene-styrene (SEBS), ABS (acrylonitrile - butadiene-styrene), acrylonitrile-ethylene-propylene-diene-styrene (AES), styrene-isoprene- styrene (SIS), methyl methacrylate-butadiene-styrene (MBS), and styrene -acrylonitrile (SAN). Exemplary elastomer-modified graft copolymers include those formed from styrene -butadiene- styrene (SBS), styrene-butadiene rubber (SBR), styrene-ethylene-butadiene-styrene (SEBS), ABS (acrylonitrile-butadiene-styrene), acrylonitrile-ethylene-propylene-diene-styrene (AES), styrene-isoprene-styrene (SIS), methyl methacrylate-butadiene-styrene (MBS), and styrene- acrylonitrile (SAN).

[0057] The compositions of the disclosure may comprise an ultraviolet (UV) stabilizer for dispersing UV radiation energy. The UV stabilizer does not substantially hinder or prevent cross-linking of the various components of the compositions of the disclosure. UV stabilizers may be hydroxybenzophenones; hydroxyphenyl benzotriazoles; cyanoacrylates; oxanilides; or hydroxyphenyl triazines. Specific UV stabilizers include, but are not limited to, Cyasorb™ 5411, Cyasorb™ UV-3638, Uvinul™ 3030, and/or Tinuvin™ 234.

[0058] The compositions of the disclosure may comprise heat stabilizers. Exemplary heat stabilizer additives include, for example, organophosphites such as triphenyl phosphite, tris- (2,6-dimethylphenyl)phosphite, tris-(mixed mono-and di-nonylphenyl)phosphite or the like; phosphonates such as dimethylbenzene phosphonate or the like; phosphates such as trimethyl phosphate, or the like; or combinations thereof.

[0059] The compositions of the disclosure may comprise an antistatic agent. Examples of monomelic antistatic agents may include glycerol monostearate, glycerol distearate, glycerol tristearate, ethoxylated amines, primary, secondary and tertiary amines, ethoxylated alcohols, alkyl sulfates, alkylarylsulfates, alkylphosphates, alkylaminesulfates, alkyl sulfonate salts such as sodium stearyl sulfonate, sodium dodecylbenzenesulfonate or the like, quaternary ammonium salts, quaternary ammonium resins, imidazoline derivatives, sorbitan esters, ethanolamides, betaines, or the like, or combinations comprising at least one of the foregoing monomelic antistatic agents. [0060] Exemplary polymeric antistatic agents may include certain polyesteramides polyether-polyamide (polyetheramide) block copolymers, polyetheresteramide block copolymers, polyetheresters, or polyurethanes, each containing polyalkylene glycol moieties polyalkylene oxide units such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like. Such polymeric antistatic agents are commercially available, for example PELESTAT™ 6321 (Sanyo) or PEBAX™ MH1657 (Atofina), IRGASTAT™ P18 and P22 (Ciba-Geigy). Other polymeric materials may be used as antistatic agents are inherently conducting polymers such as polyaniline (commercially available as PANIPOL™EB from Panipol), polypyrrole and polythiophene (commercially available from Bayer), which retain some of their intrinsic conductivity after melt processing at elevated temperatures. Carbon fibers, carbon nanofibers, carbon nanotubes, carbon black, or a combination comprising at least one of the foregoing may be included to render the compositions of the disclosure

electrostatically dissipative.

[0061] The compositions of the disclosure may comprise anti-drip agents. The anti- drip agent may be a fibril forming or non-fibril forming fluoropolymer such as

polytetrafluoroethylene (PTFE). The anti-drip agent can be encapsulated by a rigid copolymer as described above, for example styrene-acrylonitrile copolymer (SAN). PTFE encapsulated in SAN is known as TSAN. Encapsulated fluoropolymers can be made by polymerizing the encapsulating polymer in the presence of the fluoropolymer, for example an aqueous dispersion. TSAN can provide significant advantages over PTFE, in that TSAN can be more readily dispersed in the composition. An exemplary TSAN can comprise 50 wt % PTFE and 50 wt % SAN, based on the total weight of the encapsulated fluoropolymer. The SAN can comprise, for example, 75 wt% styrene and 25 wt% acrylonitrile based on the total weight of the copolymer. Alternatively, the fluoropolymer can be pre-blended in some manner with a second polymer, such as for, example, an aromatic polycarbonate or SAN to form an agglomerated material for use as an anti-drip agent. Either method can be used to produce an encapsulated fluoropolymer.

[0062] The compositions of the disclosure may comprise a radiation stabilizer, such as a gamma-radiation stabilizer. Exemplary gamma-radiation stabilizers include, but are not limited to, alkylene polyols, as well as alkoxy-substituted cyclic or acyclic alkanes. Unsaturated alkenols are also useful, examples of which include 4-methyl-4-penten-2-ol, 2-phenyl-2-butanol, 3-hydroxy-3-methyl-2-butanone, 2-phenyl-2-butanol, and the like, and cyclic tertiary alcohols such as 1 -hydroxy- 1-methyl-cyclohexane. Certain hydroxymethyl aromatic compounds that have hydroxy substitution on a saturated carbon attached to an unsaturated carbon in an aromatic ring can also be used. The hydroxy-substituted saturated carbon can be a methylol group (- CH2OH) or it can be a member of a more complex hydrocarbon group such as -CR²⁴HOH or - CR²⁴20H wherein R²⁴ is a complex or a simple hydrocarbon. Specific hydroxy methyl aromatic compounds include, e.g., benzhydrol, 1,3-benzenedimethanol, benzyl alcohol, and 4-benzyloxy benzyl alcohol. 2-Methyl-2,4-pentanediol, polyethylene glycol, and polypropylene glycol are often used for gamma-radiation stabilization.

[0063] The term "pigments" means colored particles that are insoluble in the resulting compositions of the disclosure. Exemplary pigments include titanium oxide, carbon black, carbon nanotubes, metal particles, silica, metal oxides, metal sulfides or any other mineral pigment; phthalocyanines, anthraquinones, quinacridones, dioxazines, azo pigments or any other organic pigment, natural pigments (madder, indigo, crimson, cochineal, etc.) and mixtures of pigments. The pigments may represent from 0.05% to 15% by weight relative to the weight of the overall composition. The term "dye" refers to molecules that are soluble in the compositions of the disclosure and that have the capacity of absorbing part of the visible radiation.

[0064] Pigments, dyes or fibers capable of absorbing radiation may be used to ensure the heating of an article based on the compositions of the disclosure when heated using a radiation source such as a laser, or by the Joule effect, by induction or by microwaves. Such heating may allow the use of a process for manufacturing, transforming or recycling an article made of the compositions of the disclosure.

[0065] Suitable fillers for the compositions of the disclosure include: silica, clays, calcium carbonate, carbon black, kaolin, and whiskers. Other possible fillers include, for example, silicates and silica powders such as aluminum silicate, synthetic calcium silicate, zirconium silicate, fused silica, crystalline silica graphite, natural silica sand, or the like; boron powders, oxides, calcium carbonates, talc, wollastonite, glass spheres/fibers, kaolin, single crystal fibers or "whiskers" such as silicon carbide, alumina, boron carbide, iron, nickel, copper, or the like; fibers (including continuous and chopped fibers) such as asbestos, carbon fibers, nanocellulose fibers, glass fibers, or the like; sulfides, barium compounds, metals and metal oxides, fibrous fillers, for example short inorganic fibers such as those derived from blends comprising at least one of aluminum silicates, aluminum oxides, magnesium oxides, and calcium sulfate hemihydrate or the like; natural fillers and reinforcements, organic fillers or combinations comprising at least one of the foregoing fillers or reinforcing agents.

[0066] Plasticizers, lubricants, and mold release agents can be included. Mold release agent (MRA) will allow the material to be removed quickly and effectively. Mold releases can reduce cycle times, defects, and browning of finished product. Exemplary mold release agents include, but are not excluded to combinations of methyl stearate and hydrophilic and

hydrophobic nonionic surfactants comprising polyethylene glycol polymers, polypropylene glycol polymers, poly(ethylene glycol-co-propylene glycol) copolymers, or a combination comprising at least one of the foregoing glycol polymers, e.g., methyl stearate and polyethylene- polypropylene glycol copolymer in a suitable solvent; waxes such as beeswax, montan wax, paraffin wax, or the like.

[0067] Various types of flame retardants can be utilized as additives. In one embodiment, the flame retardant additives include, for example, flame retardant salts such as alkali metal salts of perfluorinated C1-C16 alkyl sulfonates such as potassium perfluorobutane sulfonate (Rimar salt), potassium perfluoroctane sulfonate, tetraethylammonium perfluorohexane sulfonate, potassium diphenylsulfone sulfonate (KSS), and the like, sodium benzene sulfonate, sodium toluene sulfonate (NATS) and the like; and salts formed by reacting for example an alkali metal or alkaline earth metal (for example lithium, sodium, potassium, magnesium, calcium and barium salts) and an inorganic acid complex salt, for example, an oxo-anion, such as alkali metal and alkaline-earth metal salts of carbonic acid, such as sodium carbonate NaiCC , potassium carbonate K2CO3, magnesium carbonate MgCC , calcium carbonate CaCC , and barium carbonate BaCC or fluoro-anion complex such as lithium hexafluoroaluminate L13AIF6, barium hexafluorosilicate BaSiF6, potassium tetrafluoroborate KBF4, potassium

hexafluoraluminate K3AIF6, potassium aluminum fluoride KAIF4, potassium hexafluorosilicate K2S1F6, and/or sodium hexafluoroaluminate Na3AlF6 or the like. Rimar salt and KSS and NATS, alone or in combination with other flame retardants, are particularly useful in the compositions disclosed herein. In certain embodiments, the flame retardant does not contain bromine or chlorine.

[0068] The flame retardant additives may include organic compounds that include phosphorus, bromine, and/or chlorine. In certain embodiments, the flame retardant is not a bromine- or chlorine-containing composition. Non-brominated and non-chlorinated phosphorus- containing flame retardants can include, for example, organic phosphates and organic compounds containing phosphorus-nitrogen bonds. Exemplary di- or polyfunctional aromatic phosphorus-containing compounds include resorcinol tetraphenyl diphosphate (RDP), the bis(diphenyl) phosphate of hydroquinone and the bis(diphenyl) phosphate of bisphenol-A, respectively, their oligomeric and polymeric counterparts, and the like. Other exemplary phosphorus-containing flame retardant additives include phosphonitrilic chloride, phosphorus ester amides, phosphoric acid amides, phosphonic acid amides, phosphinic acid amides, tris(aziridinyl) phosphine oxide, polyorganophosphazenes, and polyorganophosphonates.

[0069] Some suitable polymeric or oligomeric flame retardants include, but are not limited to: 2,2-bis-(3,5-dichlorophenyl)-propane; bis-(2-chlorophenyl)-methane; bis(2,6- dibromophenyl)-methane; l, l-bis-(4-iodophenyl)-ethane;; and 2,2-bis-(3-bromo-4- hydroxyphenyl)-propane. Other flame retardants include: 1,3-dichlorobenzene, 1,4- dibromobenzene, l,3-dichloro-4-hydroxybenzene, and biphenyls such as 2,2'-dichlorobiphenyl, polybrominated 1,4-diphenoxybenzene, 2,4'-dibromobiphenyl, and 2,4'-dichlorobiphenyl as well as decabromo diphenyl oxide, and the like.

[0070] The flame retardant optionally is a non-halogen based metal salt, e.g., of a monomeric or polymeric aromatic sulfonate or mixture thereof. The metal salt is, for example, an alkali metal or alkali earth metal salt or mixed metal salt. The metals of these groups include sodium, lithium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, francium and barium. Examples of flame retardants include cesium benzenesulfonate and cesium p-toluenesulfonate. See e.g., US 3,933,734, EP 2103654, and US2010/0069543A1, the disclosures of which are incorporated herein by reference in their entirety.

[0071] Another useful class of flame retardants is the class of cyclic siloxanes having the general formula [(R)2SiO]_y wherein R is a monovalent hydrocarbon or fluorinated hydrocarbon having from 1 to 18 carbon atoms and y is a number from 3 to 12. Examples of fluorinated hydrocarbon include, but are not limited to, 3-fluoropropyl, 3,3,3-trifluoropropyl, 5,5,5,4,4,3,3-heptafluoropentyl, fluorophenyl, difluorophenyl and trifluorotolyl. Examples of suitable cyclic siloxanes include, but are not limited to, octamethylcyclotetrasiloxane, 1,2,3,4- tetramethyl-l,2,3,4-tetravinylcyclotetrasiloxane, eicosamethylcyclodecasiloxane,

octaphenylcyclotetrasiloxane, and the like. A particularly useful cyclic siloxane is

octaphenylcy clotetrasiloxane .

[0072] Exemplary antioxidant additives include organophosphites such as tris(nonyl phenyl)phosphite, tris(2,4-di-t-butylphenyl)phosphite ("IRGAFOS 168" or "1-168"), bis(2,4-di-t- butylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite or the like;

alkylated monophenols or polyphenols; alkylated reaction products of polyphenols with dienes, such as tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane, or the like; butylated reaction products of para-cresol or dicyclopentadiene; alkylated hydroquinones;

hydroxylated thiodiphenyl ethers; alkylidene-bisphenols; benzyl compounds; esters of beta-(3,5- di-tert-butyl-4-hydroxyphenyl)-propionic acid with monohydric or polyhydric alcohols; esters of beta-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid with monohydric or polyhydric alcohols; esters of thioalkyl or thioaryl compounds such as distearylthiopropionate,

dilaurylthiopropionate, ditridecylthiodipropionate, octadecyl-3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate, pentaerythrityl-tetrakis [3 -(3 ,5 -di-tert-butyl-4- hydroxyphenyl)propionate or the like; amides of beta-(3,5-di-tert-butyl-4-hydroxyphenyl)- propionic acid or the like, or combinations comprising at least one of the foregoing antioxidants.

[0073] The polymer compositions produced according to the disclosure can be dynamic cross-linked polymer compositions and can be used in any application which would benefit from the use of a dynamic cross-linked polymer composition. Articles, for example, molded, formed, shaped, or extruded articles, can be prepared using the polymer compositions produced according to the described methods. The term "article" refers to the compositions of the disclosure being formed into a particular shape. See, e.g., U.S. Provisional Application Nos. 62/026,458; 62/026,465; 62/138,465; 62/138,807; and 62/026,454, the entireties of which are incorporated by reference herein.

[0074] The following examples are provided to illustrate the compositions, processes, and properties of the present disclosure. The examples are merely illustrative and are not intended to limit the disclosure to the materials, conditions, or process parameters set forth therein.

EXAMPLES

Materials

[0075] Poly(butylene terephthalate) (PBT 195) granulate (M_n = 25 kg/mol, M_w = 60 kg/mol) was provided by SABIC IP (Bergen op Zoom, the Netherlands) and used as received. All chemicals were used as received, unless denoted otherwise.

[0076] Example 1 : Solution-phase preparation of a PBT /co-monomer physical mixture

[0077] Physical mixtures of PBT and multifunctional alcohol compounds were prepared from solution using a common solvent approach. The PBT 195 (Mn = 25 kg /mol and Mw= 60 kg/mol) and comonomer, together with Zn(II)(acac)2 , Cr(III)(acac)3, or others (variable mol percentage with respect to PBT repeat unit) were dissolved in HFIP (1,1,1,3,3 3- hexafluoroisopropanol). After complete dissolution of all compounds, the HFIP was distilled off. As soon as the material started to precipitate, a vacuum of -2 mbar was applied to complete the removal of HFIP. Finally, the obtained lump residue was dried under vacuum for 24 h, cooled in liquid nitrogen, and subsequently ground into powder using an IKA Al l Basic Analytical mill. This powder was subsequently dried under vacuum for a period of 24 h. The molecular weight of the polymer in the mixture was then checked to ascertain that no undesirable reactions such as transesterification or degradation occurred during the preparation procedure.

[0078] For SSM of PBT with Gly, a physical mixture of PBT and the Gly comonomer and Zn(acac)2 catalyst was prepared using the method disclosed herein. SSM was carried out using a modified version of the protocol described above. In this modified protocol, the actual SSM at 180 °C was preceded by a reaction step at lower temperatures (160 °C) for 24 hours in a closed set-up under argon overpressure to prevent Gly evaporation.

[0079] The prepolymer mixture that was thus prepared was then transferred to the SSM set-up and SSM was started. The different experimental entries of this example are summarized in Table 1 (presented in FIG. 8). The effectiveness of SSM using this prepolymer approach is demonstrated by the decrease of molecular weight of the prepolymer, followed by an increase of the molecular weight (of the soluble fraction) during SSM, as evidenced by SEC (FIG. 9(a)). The material after SSM with higher loadings of Gly was insoluble in HFIP, indicating the formation of a cross-linked network, whereas Gly incorporation in the copolyester was confirmed with ¾ NMR spectroscopy.

[0080] Table 1. Overview of PBT/Gly copolyesters prepared by SSM before gelation.

between the BDO/Gly units is expressed in mol%. ^b:The molecular weight of the PBT samples measured with SEC in HFIP as solvent.

[0082] Mechanical and rheological characterization (DMTA and stress relaxation experiments) were performed on the PBT/Gly copolyesters prepared in Example 1 to verify that these materials were cross-linked and displayed network dynamics/stress relaxation, respectively. The results of DMTA confirm network formation of the samples with > 4.0 mol% Gly: these samples possess a plateau modulus above Tm of the copolyester; the sample with 2.2 mol% Gly is not cross-linked. These findings are supported by evidence that only copolyesters with > 4.0 mol% Gly have stress relaxation timescales resembling those of dynamically cross- linked networks. Furthermore, the stress relaxation of sample PB86.sGlyi3.2T^2(Zn) obeys

Arrhenius-type behavior with temperature.

[0083] Example 2: Solid-State Modification of PBT

[0084] The solid-state modification of PBT was performed in a reactor comprising a glass tube (inner diameter = 2.4 cm) with a sintered glass plate at the bottom. A heat exchange glass coil (inner diameter = 0.5 mm) surrounded the reactor and entered the inner glass tube at the bottom just below the glass plate. The nitrogen gas was heated by passing through this coil prior to entering the reactor. The nitrogen flow was controlled by a flow meter. The following procedure was used for a PBT/Glycerol system, but those skilled in the art can modify the procedure for use with different polyesters, polyols, and transesterification catalysts.

[0085] Typically, 0.5 g of a powdered PBT/Glycerol physical mixture was placed on the sintered glass plate. The powder was fixed by addition of glass pearls (diameter = 2 mm) on top of the powder, and the reactor was purged with a nitrogen flow of 0.5 L/min for 30 min. After flushing, the reactor was placed in the salt bath (KNO3 (53 wt%), NaNC (40 wt%) and NaNC (7 wt%)) (T = 160 - 180 °C). When the temperature inside the reactor reached the predetermined temperature, the measurement of the reaction time (tssm) was initiated (Notes: the experimental conditions are slightly differing for each composition). After the reaction, the product was cooled down to room temperature by continuous nitrogen flow, discharged from the reactor, and analyzed. The obtained polymer was dried under vacuum at room temperature for 24h.

[0086] An exemplary schematic is shown in FIG. 1, which figure depicts polymer powder fixed in place by glass beads so as to allow application of gas (e.g., nitrogen gas) to the beads. As shown in that figure, a user may use beads to fix the polymer beads in place. The user may then heat the beads, e.g., to a temperature between the T_g and the Tm of the beads. Before, during, or even after heating, the user may apply a gas flow (e.g., nitrogen or other inert gas) to the beads. A user may also apply a reduced pressure to remove any volatiles (e.g., alcohols) that are evolved during formation of the dynamically cross-linked polymer composition.

[0087] The prepared PBT/polyol copolyesters can be abbreviated as e.g.

PBxPolyol_yT^z<^cat), where B_x , Polyoly and z(Metal) indicate the mol% of 1, 4-butanediol- (1, 4- BD-), Polyol-based repeat units, and mol% metal catalysts respectively according to the feed. E.g. PB76.9GLY20.6 T²-^4(Cr>: the mixture contains 76.9 mol% of PBT195, 20.6 mol% Glycerol and

[0088] Example 3: Insolubility properties in 1, 1, 1, 3, 3, 3-hexafluoroisopropanol

[0089] The permanence of the network of the polymer prepared according to Example

2 was confirmed by dissolution experiments. 1,1, 1,3,3, 3-hexafluoroisopropanol (HFIP) is a good solvent for PBT. After immersing samples of the polymer composition of Example 2 for 24 h at room temperature, they swelled, but did not dissolve.

[0090] Example 4: Glass Transition Temperature

[0091] For the polymer compositions prepared according to Example 2, the glass transition temperature (T_g) is increased as compared to neat PBT. It is theorized that this increase in T_g is attributed to the cross-links present in the polymer compositions of Example 2. When the polymer composition was fully cured, the rubbery plateau appeared and the polymer composition exhibited a modulus of about 0.3 to about 1.1 MPa, see, e.g., FIG. 2.

[0092] Example 5: Viscoelastic Properties

[0093] Linear viscoelastic properties were measured in an oscillatory mode with AR G2 TA Instruments rheometer. The storage modulus (G) and loss modulus (G") data (FIG. 3A) resulting from the dynamic frequency scan measurement, at low frequencies, show that the magnitude of G and G" both increase dramatically for the cross-linked sample (PB55 5GLY445 T^{2 5}) compared with the linear sample (PB55 5GLY445 T°). For the PBT/Glycerol sample containing 2.5 mol% of Ti(OBu)4 catalyst, the storage modulus is higher than the loss modulus (G' > G") over the entire frequency range which indicates the presence of a network; in contrast, the sample without catalyst displays predominantly a viscous behavior (G" > G') indicative for a non-crosslinked polymer melt. The 2.4 mol% Cr(acac)3 system (FIG. 3B), a gel point, that is, where the loss modulus (G") crosses over with the storage modulus (G), or G = G" and tan δ = 1, was found. If the average stress relaxation time from the frequency sweep is calculated, the approximate time is 100 s, 10 s, and 1 s at 240 °C, 270 °C, and 300 °C, respectively. If the relaxation time (τ) variation as a function of 1/T is plotted, the relaxation time also follows a simple Arrhenius law (FIG. 3C). The activation energy E_a, as determined from the slope (Ea/R), was about 12.2 KJ.mol^"1. Extrapolating to 298.15 K, the average relaxation time is about 14,415 years. Therefore, the material behaves like a classical elastomer at room temperature, since no exchange reactions would happen on relevant timescales.

[0094] Example 6: Solid State Polymerization Method

[0095] In an additional preparation process, the PBT, polyol, and catalyst are combined (e.g., via fast mixing), milled after vitrification using liquid nitrogen, placed in a vacuum oven, and then solid state polymerized to provide the reaction product. A DSM Xplore 15 ml twin- screw mini-extruder under a nitrogen flow was used to prepare the mixture for SSP. Typical extrusion parameters were as follows: temperature at 260 °C, rotospeed at 50-100 revolutions per minute (rpm), mixing time after feeding less than or equal to 30 seconds, and nitrogen flow. The extruded yarn was cut into small length, vitrified by liquid nitrogen, and subsequently ground into powder using an IKA Al l Basic Analytical mill. This powder was then dried under vacuum for a period of 24 h at 50 °C.

[0096] Molecular weight was observed and evaluated during the reactive extrusion process. FIGS. 4A and 4B show the development (D) of Mw and dispersity as a function of extrusion time (Extrusion) in the presence of zinc acetylacetonate (Zn(acac)2) with and without pentaerythritol.(B) (FIG. 4A) and the development of Mw as a function of ssp time (fep) in the presence of zinc acetylacetonate with pentaerythritol. In general, the molecular weight of PBT was decreasing as a function of extrusion time catalyzed by Zn(acac)2, and the D is nearly constant (D about 2). The molecular weight decreases faster at the first 1 minute, and then it is more or less constant as a function of extrusion time. The molecular weight decreases from 83 kg/mol to 55 kg/mol and 35 kg/mol after 10 minutes extrusion time for the system without and with 2.4 mol% pentaerythritol in the presence of 0.2 mol% Zn(acac)2, respectively. Above all, there is no molecular weight build up during reactive extrusion.

[0097] The molecular weight of the mixture prepared via a fast extrusion process was built up during solid-state (co)polymerization at 180 °C with 0.5 L min^-1 N2 flow.

Transesterification reactions occurred between the hydroxyl groups from pentaerythritol and ester groups from the PBT chains present in the amorphous phase. As shown in FIG. 4B, these recombination reactions lead to the increase of molecular weight and the material was not soluble in hexafluoroisopropanol (HFiP) when &p longer than 4.5 hours (h) at 180 °C with 0.5 liters per minute (L min^-1 N2) flow.

[0098] Also examined was the influence of different ligands of zinc salts at identical pentaerythritol content on the properties of the PBT/pentaerythritol-based vitamers. The catalysts included zinc oxide (ZnO), zinc(II) acetylacetonate (Zn(acac)2), zinc(II) acetate (Zn(OAc)2), and zinc(II) stearate.

[0099] During SSP (FIGS. 5 A and 5B), the molecular weight increased and the effects depended upon the ligands used: Zinc stearate > Zn(OAc)2 > Zn(acac)2. The D also increases similarly: Zinc stearate > Zn(OAc)2 ~ Zn(acac)2. The gelation time for zinc acetate and zinc acetylacetonate catalyzed systems during SSP was 4.5 h, while the time decreased to 4 h for zinc stearate. Zinc oxide (ZnO) was not activated in the PBT/pentaerythritol-based system, and has no effect on the molecular weight build up and copolymer architecture change in comparison to the rest of the catalysts studied herein.

[00100] The thermomechanical properties of the prepared materials are shown in FIGS. 6A and 6B. FIG. 6A presents the storage modulus (E, megapascals, MPa) as a function of temperature and FIG. 6B shows the differential scanning calorimetry (DSC) curves for heat flow according to the different ligands. Heat flow is shown with exothermic in the up direction in watts per gram (W/g). The glass transition temperatures (T_s) of the PBT vitamers containing 2.4 mol% pentaerythritol catalyzed by 0.2 mol% Zn²⁺ with different ligands are slightly higher than neat PBT. The 7g is increasing in the following manner: 7g = 55.0 °C (PBT), 58.3 °C (Zinc stearate), 60.4 °C (Zinc acetylacetonate), and 62.1 °C (Zinc acetate).

[00101] Three PBT vitamers with identical pentaerythritol and Zn(II) catalyst content exhibit similar dynamic mechanical analysis (DMA) curves, although those materials catalyzed by Zn(II) catalyst with different ligands. The thermal properties of those materials characterized by differential scanning calorimetry (DSC) show a similar degree of crystallinity about 34%, while it is 37% for neat PBT. The crystallization-peak temperature of those PBT vitamers is about 187 °C, which is slightly lower than neat PBT ( 192 °C). Nevertheless, these DSC results are in good agreement with the results obtained via DMTA. The dynamic behavior of the PBT vitamers was probed by small-amplitude oscillatory frequency sweep experiments (FIGS. 7A and 7B). The macroscopical flow behavior of the PBT/pentaerythritol-based vitamers with 2.4 mol% pentaerythritol catalyzed by 0.2 mol% zinc salts with different ligands are shown. In the examined frequency range the materials exhibit a co-dependent G' and shows much smaller G" values. Thus, in the range of frequencies tested, it behaves like a solid-like gel (G' > G"). The plateau modulus (GNO) taken at the minimum loss modulus point shows a trend in the following order: Zinc stearate > Zn(OAc)2 ~ Zn(acac)2. The materials catalyzed by Zn(OAc)2 and

Zn(acac)2 also exhibit a similar viscosity, which is about 2xl0⁷ pascal-seconds (Pa s) taken at 0.01 radians per second (rad/s). However, the viscosity of the material catalyzed by Zinc stearate is about two times higher than the ones catalyzed by Zn(OAc)2 and Zn(acac)2, which is about 4xl0⁷ Pa s. Furthermore, all viscosity curves exhibit a slope of - 1 which indicates a well- developed network.

[00102] Using reactive extrusion or compounding techniques, mixtures at an industrial scale were readily prepared. Therefore, PBT vitamer, produced with readily available feedstocks, can be easily scaled-up without using HFiP as a solvent.

[00103] Example 7 : SSM and Deprotection Methods

[00104] A solid-state modification (SSM) method was used to incorporate a polyol into poly(butylene terephthalate) (PBT) with a co-catalyst system to build up a dynamically cross- linked polymer network or a so-called vitrimer. This incorporation takes place by the transesterification reaction of the polyol with the PBT backbone, releasing 1,4-butanediol as condensate. Materials included: Poly(butylene terephthalate) (PBT 195) granulate (M_n = 25 kg/mol, Mw = 60 kg/mol) was provided by SABIC (Bergen op Zoom, the Netherlands) and used as received. Glycerol, pentaerythritol, potassium nitrate (KNO3), sodium nitrate (NaNC ), zinc(II) acetylacetonate hydrate (Zn(acac)2.H20), chromium(III) acetylacetonate, and sodium nitrite (NaNC ) were all obtained from Sigma-Aldrich. 1,1, 1,3,3, 3-hexafluoroisopropanol (HFIP, 99%) and MilliQ water (LC-MS grade) were obtained from Biosolve. Deuterated chloroform (CDCb, 99.8 atom% D) and deuterated trifluoroacetic acid (TFA-d, 99 atom% D) were obtained from Cambridge Isotope Laboratories. All chemicals were used as received, unless denoted otherwise.

[00105] Synthesis of 5,5-bis(hvdroxymethyl)-2-phenyl-l,3-dioxane (BPO).

Pentaerythritol (25.0 g, 184 millimol, mmol) was dissolved in water (180 mL) at 60 °C. After cooling the solution to room temperature, solution stirring was started and concentrated HC1 (1.0 mL) was added followed by benzaldehyde (1.0 mL, 8.2 mmol). After precipitation occurred, more benzaldehyde (22.5 mL, 185 mmol) was added dropwise and the reaction mixture was allowed to stir at room temperature for 3 h. The precipitate was filtered, washed with ice-cold slightly alkaline water (NaiCC solution), and diethyl ether Et20. Recrystallization from toluene gave 5,5-bis-(hydroxymethyl)-2-phenyl-l,3-dioxane as a colorless solid (46%). Proton nuclear magnetic resonance (¾ NMR) (400 megahertz, MHz, DMSO-de): 3.22 (d, axial exocyclic CH₂), 3.70 (d, equatorial exocyclic CH₂), 3.80 (d, C4,6 axial H), 3.90 (d, C4,6 equatorial H), 4.55 (t, axial OH), 4.62 (t, equatorial OH), 5.40 (s, benzylic H), 7.40-7.55 (m, aryl H); ¹³C NMR (400 MHz, dimethyl-sulfoxide DMSO-de): 139, 129, 128, 126 (aromatic C); 100 (C2), 69 (C4,6), 61, 59 (exocyclic CH2); ATR-FTIR : 3289 cm^"1 (OH str.), 1453 (aromatic C-C), 1038 (C-0 str.).

[00106] BPO was synthesized using the procedure disclosed herein. This comonomer was used in a series of illustrative examples with PBT, and the chemical structure of the resulting PBnPolyolmT copolymer is shown in FIG. 8. The findings for the different experimental entries of this example are summarized in Table 2 (shown in FIG. 9) and FIGS. 10A and 10D.

[00107] In Table 2: ^a Ratio between the 1,4-BDO/BPO units expressed in mol%, ^b Molar composition determined by integration of the ¾ NMR spectra, ^c Number- and weight- average molecular weights measured by SEC in HFiP , ^d Tm , Tc and degree of crystallinity (χ) (the degree of crystallinity of the synthesized copolymer is calculated by the TA Universal Analysis software with the melting enthalpy set at 142.0 joules per gram, J/g) were determined from first heating run in normal DSC mode using heating/cooling rates of 10 °C/min in a pulverous state, ^fThe molecular weight of the initial pure PBT after HFiP and without SSM treatment, ^!PBgy 5BPO25T, ³PB₈7BPOi₃T, ⁴PB₈₃ 3BPO167 T and ⁵PB₈oBP0₂oT: 160 °C for 6 h and 180 °C for 18 h under a 0.5 L/min N₂ flow;²PB₉o.9BP09.iT: 180 °C, 0 L/min N₂ flow 2 h, 1.0 L/min N₂ flow 22 h. All the copolyesters are catalyzed by 0.2 mol% Zn(acac)2.

[00108] The reaction for (PB90.9BPO9.1T^{0 2(Zn)}) was performed at 180 °C without a nitrogen flow at the initial 2 hours; nitrogen was increased to 0.5 L/min during the next 22 hours to remove the condensate. From FIGS. 10A-D, one can see that during SSP, transesterification reactions occur between the BPO comonomer and the PBT chain segments present in the amorphous phase in the presence of the transesterification catalyst (Zn(acac)2), hence it can be expected that the molecular weight will change. The number-average molecular weight ( n) and the polydispersity index (PDI) of the PBT-based copolymers (PB90.9BPO9.1T^{0 2(Zn)}) was determined by Size Exclusion Chromatography (SEC; FIG. 10A). The change of the molecular weight distribution as a function of reaction time (fep) is shown in FIG. 10B. The SEC chromatogram of the physical mixture (fep = 0 h) shows the broad peak, starting at a lower elution time, representing the PBT homopolymer.

[00109] At the initial stage of the reaction the content of unreacted hydroxyl groups of the BPO is relatively high; thus, chain scission is the dominating reaction. However, as shown in FIG. 10B, after 60 min of the SSM an increase in the molecular weight of the formed copolyester can be observed. This increase is a result of the polymer chain recombination by the

esterification and transesterification (polycondensation) reactions that take place between reactive end groups of chains present in the copolyester with elimination of the condensation product 1,4-butanediol. This reaction dominates over chain scission when the content of unreacted hydroxyl groups decreases. Moreover, a sharp decrease in the peak intensity related to the unreacted BPO (marked with an asterisk in FIG. 10A) is clearly visible at an elution time of ~29 min.

[00110] From the ¾ NMR spectra presented in FIG. 10C, it can be noted that the signal related to the CH2 next to the hydroxyl groups of BPO, which had not yet participated in the formation of ester bonds appears at 4.55-4.62 parts per million (ppm); however, after the transesterification reaction these signals have shifted to lower field (signal b'), moreover, the benzylic proton also shifts from 5.40 ppm to 5.50 ppm. Without being bound to any particular theory, this demonstrates the desired transesterification between the BPO OH end groups and the PBT ester groups, converting the free hydroxyl groups of the BPO into ester groups present in the backbone of the PB_nBPO_yT copolyester. The comonomer ratio in the copolyesters are determined by integration of the peaks at 8.10 ppm (1,4-phenylene) and 5.50 ppm (benzylic). When fe_P > 3 h, all BPO is fully incorporated (see FIG. 10D).

[00111] Deprotection of PBT/BPO copolyesters by acid end-groups. This example provides a method that allows for faster and easier debenzalation of PBT/BPO copolyesters on experimentally relevant sample scales and without the need for other chemicals or subsequent processing steps. This method is based on the autocatalytic activity of the terephthalic acid (COOH) end-groups in the PBT resin that are able to effectively catalyze debenzalation at processing temperatures of the PBT/BPO copolyester, resulting in the in-situ formation of a (pre- dynamically or dynamically) cross-linked copolyester composition.

[00112] This autocatalytic debenzalation is evidenced when looking at the storage modulus of PBnBPOmT copolyesters with varying compositions as measured by DMTA (FIG. 11 A): For compositions with higher amounts of BPO comonomer (> 9.1 mole% BPO), the plateau modulus above T_m appears, even though these samples were not yet exposed to TFA (trifluoroacetic acid, used to debenzalate) treatment. The presence of the plateau modulus above Tm indicates the improvement of melt strength which is an indication of network formation, as mentioned before.

[00113] Additional experimental evidence for debenzalation by COOH end-groups is shown in FIG. 10B, where the loss moduli of two PBnBPOmT copolyesters compositions are compared before and after TFA treatment. FIG. 11 A shows that for the PBnBPOmT copolyesters with 9.1 mol% BDO, a plateau modulus above T_m is already present before TFA treatment. In addition, FIG. 1 IB shows only marginal increase of the plateau modulus after TFA treatment, indicating that a significant degree of debenzalation had already occurred during processing steps prior to TFA treatment.

[00114] It is thus possible to prepare the materials without an extra deprotection procedure, and this thermal deprotection phenomenon is favorable to the polymer process, since this controlled release of hydroxyl group process can protect the material from degradation. Without being bound to any particular theory, one possible mechanism is that the benzaldehyde group is deprotected by the carboxylic acid end group from the PBT backbone at elevated temperature, then free hydroxyl groups are released, and can participate in the transesterification reaction catalyzed by zinc(II) acetylacetonate or other catalysts, which eventually form a dynamically cross-linked polymer network, e.g., FIG. 12.

[00115] Stress relaxation measurements of PBT/BPO copolyesters and the

corresponding dynamic networks. To confirm that the copolyester networks formed after deprotection of PBnBPOmT were dynamically cross-linked networks, stress relaxation experiments were performed. Stress relaxation of these networks was measured by following the decay of the storage modulus of a pre-strained sample over time at varying temperatures using a plate/plate rheometer set-up. The stress relaxation curves obtained for protected and deprotected PB90.9BDO9.1T copolyesters with 0.2 mol% of Zn(acac)2 catalyst are shown in FIGS. 13A and B .

[00116] Stress relaxation is plotted as the normalized storage modulus G(t)/G(0) versus time t. Based on FIGS. 13A-B, the normalized storage modulus decays exponentially with time, having one or, in some cases, two characteristic timescales. This type of stress relaxation behavior can be described by the following equation: G(t)IG(Q) = gi exp(-i/ri*) + gi exp(-t/n*).

[00117] In this equation, G(t = 0) indicates the value of the storage modulus at the inception of the rheology measurement (/^'. e. , at t = 0), gi and gi are constants (gi = 0 if only one characteristic relaxation timescale and τι* and T2* are the characteristic relaxation time scales. For a mono-exponential decay {i.e. , gi = 0), n* corresponds to the time where G(t) has decayed to -37% of its initial value; thus G(T*) = 1/e * G(0) « 0.37G(0).

[00118] As can be seen from FIGS. 13A-B, the stress relaxation process of the protected copolyester appears faster than for the deprotected system. Without being bound to any particular theory, on one hand, the deprotected copolyester has more hydroxyl (OH) groups, which will lead to fast degradation at higher temperature and destroy the exchangeable network, on the other hand, during the deprotection procedure by trifluoroacetic acid TFA, it may also wash away a certain amount of the zinc(II) catalyst. Both the stress relaxation time and viscosity follow an Arrhenius law, which is seen for other types of dynamic polymer networks as well, when cross-link exchange reaction govern network dynamics and relaxation. FIG. 14 provides Arrhenius plots showing the relationship between characteristic relaxation time and viscosity of PB90.9BDO9.1T copolyester and the corresponding dynamic network as obtained from data analysis of the stress relaxation experiments shown in FIGS. 13A-B . FIG. 15 A shows an evolution of the molecular weight distribution during prepolymerization and SSM of

PB86.8Glyi3.2T^2(Zn) PBT/Gly copolyester. FIG. 15B provides expanded regions (3.75-6.35 ppm) of the ¾ NMR spectra before and after prepolymerization: (1) PBs5.4Glyi4.6T^2(Zn) physical mixture; (2) branched PGlyT; (3) PB₈6.8Glyi3.2T^2(Zn) at fem = 1 h; (4) PB₉6.oGly4.oT^2(Zn) at t_ssm = 7 h; and PB97.8Gly2.2T^2(Zn) at fem = 7

Exemplary Aspects

[00119] The disclosure relates to at least the following aspects.

[00120] Aspect 1A. A method of forming a polymer composition by solid-state modification, the method comprising: forming a solid solution that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; reacting and heating the polyol component and the polyester component at a temperature between about the glass transition temperature Tg and the melting temperature Tm of the polyester component so as to form cross-links among polymer chains of the polyester component so as to give rise to a pre -dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition that comprises amorphous and crystalline polyester regions.

[00121] Aspect IB. A method of forming a polymer composition by solid-state modification, the method consisting essentially of: forming a solid solution that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; reacting and heating the polyol component and the polyester component at a temperature between about the Tg and the Tm of the polyester component so as to form cross-links among polymer chains of the polyester component so as to give rise to a pre- dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition that comprises amorphous and crystalline polyester regions.

[00122] Aspect 1C. A method of forming a polymer composition by solid-state modification, the method consisting of: forming a solid solution that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; reacting and heating the polyol component and the polyester component at a temperature between about the Tg and the Tm of the polyester component so as to form cross-links among polymer chains of the polyester component so as to give rise to a pre- dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition that comprises amorphous and crystalline polyester regions.

[00123] Aspect 2. The method of claim 1, further comprising forming the solid solution by at least one of (a) contacting the polyol component and the polyester component in the presence of a solvent, removing at least some of the solvent, and effecting crystallization of at least some of the polyester component and (b) effecting melt-phase mixing and cooling of the polyol, and polyester components and the transesterification catalyst.

[00124] Aspect 3. The method of any of claims 1-2, further comprising including in at least one of the dynamically cross-linked composition and solid solution a pigment, a dye, a filler, a plasticizer, a fiber, a flame retardant, an antioxidant, a lubricant, wood, glass, metal, an ultraviolet agent, an anti-static agent, an anti-microbial agent, or a combination thereof.

[00125] Aspect 4. The method of any of claims 1-3, further comprising heating the pre-dynamically cross-linked network polymer composition at a temperature from about the T_g to about the T_m of the composition.

[00126] Aspect 5. The method of claim 4, further comprising removing one or more volatile components evolved during the heating.

[00127] Aspect 6A. A method of forming a polymer composition by solid-state modification, comprising: with a solution that comprises: a polyol component that comprises an amount of one or more polyols, a polyester component, and a transesterification catalyst;

forming, from the solution, a solid that comprises an amount of the polyester in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the solid at a temperature between the T_g and T_m of the polyester in at least partially crystalline form so as to form a pre-dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition.

[00128] Aspect 6B. A method of forming a polymer composition by solid-state modification, the method consisting essentially of: with a solution that comprises: a polyol component that comprises an amount of one or more polyols, a polyester component, and a transesterification catalyst; forming, from the solution, a solid that comprises an amount of the polyester in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the solid at a temperature between the T_g and T_m of the polyester in at least partially crystalline form so as to form a pre-dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition.

[00129] Aspect 6C. A method of forming a polymer composition by solid-state modification, the method consisting essentially of: with a solution that comprises: a polyol component that comprises an amount of one or more polyols, a polyester component, and a transesterification catalyst; forming, from the solution, a solid that comprises an amount of the polyester in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the solid at a temperature between the T_g and T_m of the polyester in at least partially crystalline form so as to form a pre-dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition.

[00130] Aspect 7. The method of claim 6, further comprising application of an inert gas to the solution, the solid, or to both.

[00131] Aspect 8. The method of any of claims 6-7, further comprising removing one or more volatile components.

[00132] Aspect 9. The method of any of claims 6-8, further comprising grinding the solid so as to place the solid into particulate form.

[00133] Aspect 10. The method of any of claims 6-9, further comprising curing the pre-dynamically cross—linked network polymer composition at a temperature from about the T_g to about the T_m of the at least partially crystalline polyester.

[00134] Aspect 11. A dynamically cross-linked network polymer composition, comprising: a polyester that comprises a plurality of crystalline regions bound to amorphous regions, at least some amorphous regions being cross-linked to one another by cross-links that comprise a reacted polyol component.

[00135] Aspect 12. The dynamically cross-linked network polymer composition of claim 11, wherein the composition is made according to any of claims 1-10.

[00136] Aspect 13. The dynamically cross-linked network polymer composition of any of claims 11-12, wherein the polyester comprises a poly(alkylene terephthalate).

[00137] Aspect 14. The dynamically cross-linked network polymer composition of any of claims 11-13, wherein the composition defines a molded article.

[00138] Aspect 15. A composition, comprising: in solid form, an at least partially crystalline polyester in particulate form, a polyol comprising at least three hydroxyl groups, and a transesterification catalyst.

[00139] Aspect 16. The composition of claim 15, wherein the at least partially crystalline polyester in particulate form has a D50 volume average particle cross-sectional dimension in the range of from about 5 micrometers to about 150 micrometers.

[00140] Aspect 17A. A composition comprising: a dynamically cross-linked copolymer that comprises repeat units of (a) a polyester and (b) the product of a polyol reacted with the polyester.

[00141] Aspect 17B. A composition consisting essentially of: a dynamically cross- linked copolymer that comprises repeat units of (a) a polyester and (b) the product of a polyol reacted with the polyester.

[00142] Aspect 17C. A composition consisting of: a dynamically cross-linked copolymer that comprises repeat units of (a) a polyester and (b) the product of a polyol reacted with the polyester.

[00143] Aspect 18. The composition of claim 17, wherein the polyester comprises a poly(alkylene terephthalate).

[00144] Aspect 19. The composition of any of claims 17-18, wherein the polyester comprises a poly(butylene terephthalate), a poly(ethylene terephthalate), or any combination thereof.

[00145] Aspect 20. The composition of any of claims 17-19, wherein the polyol comprises at least three hydroxyl groups.

[00146] Aspect 21 A. A method of forming a polymer composition by solid-state modification, the method comprising: forming a mixture that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; heating the mixture at a temperature between about the Tg and the Tm of the polyester component so as to form cross-links among the polymer chains so as to give rise to a pre-dynamically cross-linked network polymer composition or a dynamically cross- linked network polymer composition that comprises amorphous and crystalline polyester regions.

[00147] Aspect 2 IB. A method of forming a polymer composition by solid-state modification, the method comprising: forming a mixture that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; heating the mixture at a temperature between about the Tg and the Tm of the polyester component so as to form cross-links among the polymer chains so as to give rise to a pre-dynamically cross-linked network polymer composition or a dynamically cross- linked network polymer composition that comprises amorphous and crystalline polyester regions.

[00148] Aspect 21 C. A method of forming a polymer composition by solid-state modification, the method comprising: forming a mixture that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; heating the mixture at a temperature between about the Tg and the Tm of the polyester component so as to form cross-links among the polymer chains so as to give rise to a pre-dynamically cross-linked network polymer composition or a dynamically cross- linked network polymer composition that comprises amorphous and crystalline polyester regions. [00149] Aspect 22. The method of any of claims 21 A-21C, wherein the mixture comprises a solid solution.

[00150] Aspect 23. The method of claim 22, further comprising forming the solid solution by at least one of (a) contacting the polyol component and the polyester component in the presence of a solvent, removing at least some of the solvent, and effecting crystallization of at least some of the polyester component and (b) effecting melt-phase mixing and cooling of the polyol, and polyester components and the transesterification catalyst.

[00151] Aspect 24. The method of any of claims 21 A-21C, wherein the mixture comprises a powder.

[00152] Aspect 25. The method of any of claims 21 A-21C, wherein the mixture is formed by reactive extrusion and processed to provide a powder.

[00153] Aspect 26. The method of any of claims 21A-25, further comprising including in at least one of the dynamically cross-linked composition, a dye, a filler, a plasticizer, a fiber, a flame retardant, an antioxidant, a lubricant, wood, glass, metal, an ultraviolet agent, an anti-static agent, an anti-microbial agent, or a combination thereof.

[00154] Aspect 27. The method of any of claims 21A-26, further comprising heating the pre-dynamically cross-linked network polymer composition at a temperature from about the T_g to about the T_m of the composition.

[00155] Aspect 28A. A method of forming a polymer composition by solid-state modification, the method comprising: forming a mixture that comprises: a polyol component that comprises an amount of one or more polyols, a polyester component, and a transesterification catalyst; forming, extruding the mixture to provide an extrudate, milling the extrudate to provide a powder wherein the powder comprises an amount of the polyester component in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the powder at a temperature between the T_g and T_m of the at least partially crystalline polyester so as to form a pre-dynamically cross-linked network polymer composition or a dynamically cross- linked network polymer composition.

[00156] Aspect 28B. A method of forming a polymer composition by solid-state modification, the method comprising: forming a mixture that comprises: a polyol component that comprises an amount of one or more polyols, a polyester component, and a transesterification catalyst; forming, extruding the mixture to provide an extrudate, milling the extrudate to provide a powder wherein the powder comprises an amount of the polyester component in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the powder at a temperature between the T_g and T_m of the at least partially crystalline polyester so as to form a pre-dynamically cross-linked network polymer composition or a dynamically cross- linked network polymer composition.

[00157] Aspect 28C. A method of forming a polymer composition by solid-state modification, the method comprising: forming a mixture that comprises: a polyol component that comprises an amount of one or more polyols, a polyester component, and a transesterification catalyst; forming, extruding the mixture to provide an extrudate, milling the extrudate to provide a powder wherein the powder comprises an amount of the polyester component in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the powder at a temperature between the T_g and Tm of the at least partially crystalline polyester so as to form a pre-dynamically cross-linked network polymer composition or a dynamically cross- linked network polymer composition.

[00158] Aspect 29. The method of any of claims 28A-28C, further comprising including in at least one of the dynamically cross-linked composition a pigment, a dye, a filler, a plasticizer, a fiber, a flame retardant, an antioxidant, a lubricant, wood, glass, metal, an ultraviolet agent, an anti-static agent, an anti-microbial agent, or a combination thereof.

[00159] Aspect 30. The method of any of claims 28A-28C, further comprising heating the pre-dynamically cross-linked network polymer composition at a temperature from about the Tg to about the Tm of the composition.

[00160] Aspect 31. A method of forming a polymer composition, the method comprising: combining: a polyester component, a polyol comonomer that comprises a phenyl dioxane, and a transesterification catalyst, the combining being performed so as to give rise to a protected copolyester that comprises the phenyl dioxane, and the combining being performed at a combination temperature between the Tg and the Tm of polyester component; converting, to hydroxyls, the phenyl dioxane of the protected copolyester so as to form a deprotected copolyester, the converting being effectuated under conditions sufficient to debenzalate the phenyl dioxane of the protected polyester to hydroxyls by reaction of an acid group of the protected copolyester, an acid group of the deprotected polyester, or both, with the phenyl dioxane; and cross-linking deprotected copolyester molecules so as to form a pre-dynamically or dynamically cross-linked network material.

[00161] Aspect 32. The method of claim 1, wherein the converting comprises exposing to a temperature sufficient to effect the debenzalation.

[00162] Aspect 33. The method of any of claims 1-2, wherein the transesterification catalyst comprises zinc (II) acetylacetonate, chromium (III) acetylacetonate, or any combination thereof.

[00163] Aspect 34. The method of any of claims 1-3, wherein the polyester component comprises a poly(alkylene terephthalate).

[00164] Aspect 35. The method of any of claims 1-4, wherein the polyol comprises a glycerol, a trimethylolpropane, a pentaerythritol, or any combination thereof.

[00165] Aspect 36. The method of any of claims 1-5, wherein the combining is effectuated in a reactive extruder.

[00166] Aspect 37. The method of any of claims 1-6, wherein one or more of the combining, converting, and cross-linking is effectuated at a temperature between the glass transition temperature and the melting temperature of the (de)protected copolyester.

[00167] Aspect 38. The method of any of claims 1-7, wherein the converting is effectuated in an essentially solvent-free environment.

[00168] Aspect 39. The method of any of claims 1-8, further comprising curing the dynamically cross-linked network material.

[00169] Aspect 40. A method of forming a polymer composition, comprising:

converting to hydroxyls a phenyl dioxane of a copolyester that comprises an acid group so as to form a deprotected copolyester, the converting being effectuated by exposing the copolyester to conditions sufficient to effect reaction of an acid group of the protected copolyester, an acid group of the deprotected polyester, or both, with the phenyl dioxane; and cross-linking copolyester molecules.

[00170] Aspect 41. The method of claim 10, wherein the phenyl dioxane comprises a 2-phenyl-l,3, dioxane.

[00171] Aspect 42. The method of any of claims 10-11, wherein the protected copolyester is formed from condensation of a polyol and a polyester.

[00172] Aspect 43. The method of claim 12, wherein the protected copolyester is formed from the condensation of poly(butylene terephthalate) and 5,5-bis-(hydroxymethyl)-2- pheny 1- 1 , 3 -dioxane .

[00173] Aspect 44. The method of any of claims 10-13, wherein the converting comprises exposure to a temperature in the range of from about 120 to about 200 °C.

[00174] Aspect 45. A pre dynamically-crosslinked polymer network or dynamically- crosslinked polymer network formed according to any of claims 1-14.

[00175] Aspect 46. A dynamically cross-linked composition, comprising: a polyester that comprises a plurality of crystalline regions bound to amorphous regions, at least some of the amorphous regions including cross-links that comprise a reacted polyol component.

[00176] Aspect 47. The composition of claim 16, wherein the polyester comprises a poly(alkylene terephthalate).

[00177] Aspect 48. A method, comprising: forming a solution that comprises: a polyol component that comprises a phenyl dioxane and at least two hydroxyl groups, a polyester component that comprises amorphous regions and crystalline regions , and a transesterification catalyst; solidifying the solution; polymerizing the polyol component and the polyester component so as to form polymer chains that comprise the phenyl dioxane; converting the phenyl dioxane of the polyol component to hydroxyls; and forming crosslinks among the polymer chains so as to give rise to a pre dynamically -crosslinked polymer network or dynamically crosslinked network polymer composition.

[00178] Aspect 49. The method of claim 18, wherein the converting to hydroxyls is effected under conditions sufficient to convert the phenyl dioxane of the protected polyester to hydroxyls by reaction of an acid group of the protected copolyester, an acid group of the deprotected polyester, or both, with the phenyl dioxane.

[00179] Aspect 50. A composition, comprising: in solid form, an at least partially crystalline polyester in particulate form, a polyol comprising at least two hydroxyl groups and a diphenol dioxane, and a transesterification catalyst.

[00180] In one aspect, the present disclosure provides methods of forming a polymer composition by solid-state modification, comprising: with a solid solution that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; reacting and heating the polyol component and the polyester component at a temperature between about the Tm and the Tg of the polyester component so as to form cross-links among the polymer chains so as to give rise to a pre-dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition that comprises amorphous and crystalline polyester regions.

[00181] It should be understood that the formation of a pre-dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition that comprises amorphous and crystalline polyester regions may depend on the reaction kinetics of the particular reactants being used, which kinetics may be influenced by various conditions, e.g., temperature and catalyst.

[00182] The methods may further include forming the solid solution by at least one of (a) contacting the polyol component and the polyester component in the presence of a solvent, removing at least some of the solvent, and effecting crystallization of at least some of the polyester component and (b) effecting melt-phase mixing and cooling of the polyol, and polyester components and the transesterification catalyst. Without being bound to any particular theory, cooling may result in crystallization of at least some of the polyester.

[00183] A polyol may comprise two or more -OH groups. Suitable polyols include glycerol, trimethylolpropane, pentaerythritol, or any combination thereof.

[00184] A variety of polyesters may be used in the disclosed technology; poly(alkylene terephthalate) is considered an especially suitable polyester. The poly(alkylene terephthalate) may comprise poly(butylene terephthalate), poly(ethylene terephthalate), or any combination thereof.

[00185] One may include in at least one of the dynamically cross-linked composition and solid solution a pigment, a dye, a filler, a plasticizer, a fiber, a flame retardant, an antioxidant, a lubricant, wood, glass, metal, an ultraviolet agent, an anti-static agent, an antimicrobial agent, or a combination thereof. The foregoing additives are described elsewhere herein in detail; fibers (e.g., glass or carbon fibers) are considered especially suitable.

[00186] The methods may further comprise curing the pre -dynamically cross-linked network polymer composition, when present, at a temperature from about the T_g to about the T_m of the composition. This curing may give rise to formation of a dynamically-crosslinked network polymer composition from the pre-dynamically-crosslinked network polymer composition. The methods may also include removing one or more volatile components evolved during the curing. This may be accomplished by venting the system to the exterior environment, by purging or flushing a reaction vessel, or any combination thereof.

[00187] The present disclosure also provides methods of forming a polymer composition by solid-state modification, comprising: with a solution that comprises: a polyol component that comprises an amount of one or more polyols, a polyester component, and a transesterification catalyst, forming, from the solution, a solid that comprises an amount of the polyester in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the solid at a temperature between the T_g and Tm of the at least partially crystalline polyester so as to form a pre-dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition.

[00188] The methods may comprise application of an inert gas to the solution, the solid, or both. One may also remove one or more volatile components during the methods. [00189] One may grind the solid so as to place the solid into particulate form. This may be done cryogenically or by other methods known to those of skill in the art. The at least partially crystalline particulate form polyester may have a D50 volume average particle cross- sectional dimension in the range of from about 5 micrometers to about 150 micrometers. The methods may also include curing the pre-dynamically cross-linked network polymer composition at a temperature from about the T_g to about the T_m of the at least partially crystalline polyester. . D50 may refer to the particle diameter of the particles where 50 wt% of the particles in the total distribution of the referenced sample have the noted particle diameter or smaller.

[00190] In further aspects, the present disclosure provides methods of forming a polymer composition, the methods comprising: combining a polyester component, a polyol comonomer that comprises a phenyl dioxane, and a transesterification catalyst, the combining being performed so as to give rise to a protected copolyester that comprises the phenyl dioxane, and the combining being performed at a combination temperature between the Tg and the Tm of polyester component; converting, to hydroxyls, the phenyl dioxane of the protected copolyester so as to form a deprotected copolyester, the converting being effectuated under conditions sufficient to debenzalate the phenyl dioxane of the protected polyester to hydroxyls by reaction of an acid group of the protected copolyester, an acid group of the deprotected polyester, or both, with the phenyl dioxane; and cross-linking deprotected copolyester molecules so as to form a pre dynamically-crosslinked polymer network or dynamically cross-linked network material. (As described elsewhere herein, a pre-dynamically crosslinked polymer network may be cured to as to form a dynamically cross-linked polymer network.) The polyol that comprises the phenyl dioxane may be, e.g., comprises a 2-phenyl-l,3, dioxane; essentially any 1,3 dioxane is considered suitable.

[00191] The converting to hydroxyls may comprise exposure to a temperature sufficient to effect the debenzalation. A protected polyester is prepared via solid-state modification and exposure to a temperature between the polyester's Tg and Tm. During melt processing above the melting temperature of the polymer, the deprotection occurs. Cross-linking may be effected exposure to a suitable temperature for the polymer (and catalyst, as may be needed), e.g., in the range of from about 120 °C, to about 200 °C. Suitable catalysts include zinc (II) acetylacetonate, chromium (III) acetylacetonate, or any combination thereof.

[00192] The polyester may comprise, e.g., a poly(alkylene terephthalate) such as poly(butylene terephthalate). One suitable polyol that comprises a phenyl dioxane is 5,5-bis- (hydroxymethyl)-2 -phenyl- 1,3 -dioxane. The polyol that comprises the phenyl dioxane has a melting temperature above the melting temperature of the polyester component. The polyol that comprises the phenyl dioxane has a melting temperature below about 180 °C.

[00193] One or more of the disclosed steps, e.g., the combining, the converting, or more, may be performed in a reactive extruder. One or more of the combining, converting, and cross-linking may be effectuated at a temperature between the glass transition temperature and the melting temperature of the (de)protected copolyester. Converting may be effectuated in an essentially solvent-free environment. The disclosed methods may further include curing the synthesized material (e.g., a pre dynamically cross-linked network material), e.g., between the Tg and Tm of the material, so as to give rise to a dynamically-crosslinked polymer network.

[00194] The present disclosure also provides methods of forming a polymer composition, comprising converting to hydroxyls of a phenyl dioxane of a copolyester that comprises an acid group so as to form a deprotected copolyester, the converting being effectuated by exposing the copolyester to conditions sufficient to effect reaction of an acid group of the copolyester, an acid group of the deprotected polyester, or both, with the phenyl dioxane; and effecting cross-linking between copolyester molecules. (It should be understood that cross-linking can be done before or after deprotection.) As described elsewhere herein, the phenyl dioxane may comprise a 2-phenyl-l,3, dioxane. The protected copolyester may be formed from condensation of a polyol and a polyester. As one example, the protected copolyester may be formed from the condensation of poly(butylene terephthalate) and 5,5-bis- (hydroxymethyl)-2 -phenyl- 1,3 -dioxane. Without being bound to any particular range, the converting comprises exposure to a temperature in the range of from about 120 to about 200 °C, e.g., from about 120 to about 150 °C.

[00195] The present disclosure also provides pre dynamically-crosslinked polymer network and dynamically-crosslinked polymer networks; such networks may be formed according to the present disclosure. Also provided are pre dynamically-crosslinked polymer network and dynamically cross-linked compositions, comprising a polyester that comprises a plurality of crystalline regions bound to amorphous regions, at least some of the amorphous regions including cross-links that comprise a reacted polyol component. The polyester may further comprise a plurality of hydroxy 1 groups.

[00196] Such compositions may be made according to the methods described herein. As discussed elsewhere herein, the polyester may comprise a poly(alkylene terephthalate), e.g., poly(butylene terephthalate). Methods may comprise forming a solution that comprises a polyol component that comprises a phenyl dioxane and at least two hydroxyl groups, a polyester component that comprises amorphous regions and crystalline regions , and a transesterification catalyst; solidifying the solution; polymerizing the polyol component and the polyester component so as to form polymer chains that comprise the phenyl dioxane; converting the phenyl dioxane of the polyol component to hydroxyls; and forming cross-links among the polymer chains so as to give rise to a pre dynamically -crosslinked polymer network or a dynamically cross-linked network polymer composition.

[00197] Converting to hydroxyls may be effected under conditions sufficient to convert the phenyl dioxane of the protected polyester to hydroxyls by reaction of an acid group of the protected copolyester, an acid group of the deprotected polyester, or both, with the phenyl dioxane.

[00198] Also provided are compositions comprising: in solid form, an at least partially crystalline polyester in particulate form, a polyol comprising at least two hydroxyl groups and a diphenol dioxane, and a transesterification catalyst. The at least partially crystalline polyester in solid form may be in a particulate form having an average diameter in the range of from about 10 to about 150 micrometers. The at least partially crystalline polyester in particulate form may also have a D50 in the range of from about 5 to about 150 micrometers. The population of particles may have a D50 volume average particle cross-sectional dimension in the range of from about 5 micrometers to about 150 micrometers, e.g., from about 10 micrometers to about 140 micrometers, or from about 20 micrometers to about 130 micrometers, or from about 30 micrometers to about 120 micrometers, or from about 40 micrometers to about 110 micrometers, or from about 50 micrometers to about 100 micrometers, or from about 60 micrometers to about 90 micrometers, or from about 70 micrometers to about 80 micrometers. A user may perform a sieving step to assist in isolating particles of the desired size, e.g., from about 10 to about 150 micrometers in cross-sectional dimension.

[00199] In further examples, the at least a portion of polyester that is at least partially crystalline polyester in particulate form may have a D50 (or Dv50) volume average particle cross-sectional dimension in the range of from about 5 micrometers (μπι) to 2 millimeters (mm) or 3 mm. Further background on solid-state polymerization as well as exemplary particle sizes are also described by Papaspyridis, et. al, Solid State Polymerization (1st ed. 2009). The at least partially crystalline polyester may have a crystallinity in the range of from about 1 to about 90%, or from about 5 to about 85%, or from about 10 to about 80%, or from about 15 to about 75%, or from about 20 to about 70%, or from about 25 to about 65%, or from about 30 to about 60%, or from about 35 to about 55%, or from about 40 to about 50%, or about 45%. [00200] In yet further aspects, methods may relate to reactive extrusion of the components prior to solid state polymerization rather than use of a solvent such as 1,1,1,3,3,3- hexafluoroisopropanol(HFIP), which generally expensive and toxic. As an example, the PBT, polyol, and catalyst are combined (e.g., via fast mixing), vitrified using liquid nitrogen, and milled to provide a powder. The resultant powder may be solid state polymerized to provide the reaction product. Combining may be achieved via reactive extrusion, particularly under a nitrogen flow. General extrusion parameters comprise: temperature at 260 °C, rotospeed at 50- 100 revolutions per minute (rpm), mixing time after feeding less than or equal to 30 seconds, and nitrogen flow. The molecular weight of the mixture prepared via extrusion process is increased during solid-state (co)polymerization Transesterification reactions occurred between the hydroxyl groups from pentaerythritol and ester groups from the PBT chains present in the amorphous phase.

[00201] Polymer resins in fine powder form are usually aggregated because of the attractive Van der Waals forces and/or electrostatic forces. Due to that phenomenon, thermoplastic powders with particle sizes suitable for solid-state modification, typically having an average particle size of less than about 150 micrometers, may be agglomerated and form clumps of powder cakes that exhibit poor powder flow or packing properties to obtain the right packing density to remove the condensation products.

[00202] Also provided are dynamically cross-linked network polymer compositions, comprising a polyester that comprises a plurality of crystalline regions bound to amorphous regions, at least some of the amorphous regions being cross-linked to one another by cross-links that comprise a reacted polyol component. The dynamically cross-linked network polymer composition may be made according to the disclosed methods. The polyester of the composition may comprise a poly(alkylene terephthalate); e.g., poly(butylene terephthalate), a poly(ethylene terephthalate), or any combination thereof. The composition may define a molded article; the molding may be injection molding or other molding techniques.

[00203] Other disclosed compositions may comprise a dynamically cross-linked copolymer that comprises repeat units of (a) a polyester and (b) the product of a polyol reacted with the polyester. The polyester comprises a poly(alkylene terephthalate), e.g., poly(butylene terephthalate), a poly(ethylene terephthalate), or any combination thereof. The polyol may comprise two, three, or more hydroxyl groups.

Claims

What is Claimed:

1. A method of forming a polymer composition by solid-state modification, the method comprising: forming a solid solution that comprises (a) a polyol component that comprises an amount of one or more polyols, (b) a polyester component, and (c) a transesterification catalyst; reacting and heating the polyol component and the polyester component at a temperature between about the glass transition temperature Tg and the melting temperature Tm of the polyester component so as to form cross-links among polymer chains of the polyester component so as to give rise to a pre -dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition that comprises amorphous and crystalline polyester regions.

2. The method of claim 1, further comprising forming the solid solution by at least one of (a) contacting the polyol component and the polyester component in the presence of a solvent, removing at least some of the solvent, and effecting crystallization of at least some of the polyester component and (b) effecting melt-phase mixing and cooling of the polyol, and polyester components and the transesterification catalyst.

3. The method of any of claims 1-2, further comprising including in at least one of the dynamically cross-linked composition and solid solution a pigment, a dye, a filler, a plasticizer, a fiber, a flame retardant, an antioxidant, a lubricant, wood, glass, metal, an ultraviolet agent, an anti-static agent, an anti-microbial agent, or a combination thereof.

4. The method of any of claims 1-3, further comprising heating the pre-dynamically cross- linked network polymer composition at a temperature from about the T_g to about the T_m of the composition.

5. The method of claim 4, further comprising removing one or more volatile components evolved during the heating.

6. A method of forming a polymer composition by solid-state modification, the method comprising: with a solution that comprises:

a polyol component that comprises an amount of one or more polyols, a polyester component, and

a transesterification catalyst; forming, from the solution, a solid that comprises an amount of the polyester in at least partially crystalline form, the polyol component, and the transesterification catalyst; heating the solid at a temperature between the T_g and T_m of the polyester in at least partially crystalline form so as to form a pre -dynamically cross-linked network polymer composition or a dynamically cross-linked network polymer composition.

7. The method of claim 6, further comprising application of an inert gas to the solution, the solid, or to both.

8. The method of any of claims 6-7, further comprising removing one or more volatile components.

9. The method of any of claims 6-8, further comprising grinding the solid so as to place the solid into particulate form.

10. The method of any of claims 6-9, further comprising curing the pre-dynamically cross- linked network polymer composition at a temperature from about the T_g to about the T_m of the at least partially crystalline polyester.

11. A dynamically cross-linked network polymer composition, comprising: a polyester that comprises a plurality of crystalline regions bound to amorphous regions, at least some amorphous regions being cross-linked to one another by cross-links that comprise a reacted polyol component.

12. The dynamically cross-linked network polymer composition of claim 11, wherein the composition is made according to the method of any of claims 1-10.

13. The dynamically cross-linked network polymer composition of any of claims 11-12, wherein the polyester comprises a poly(alkylene terephthalate).

14. The dynamically cross-linked network polymer composition of any of claims 11-13, wherein the composition defines a molded article.

15. A composition comprising: in solid form, an at least partially crystalline polyester in particulate form, a polyol comprising at least three hydroxyl groups, and a transesterification catalyst.

16. The composition of claim 15, wherein the at least partially crystalline polyester in

particulate form has a D50 volume average particle cross-sectional dimension in the range of from about 5 micrometers to about 150 micrometers.

17. A composition comprising: a dynamically cross-linked copolymer that comprises repeat units of (a) a polyester and (b) a product of a polyol reacted with the polyester.

18. The composition of claim 17, wherein the polyester comprises a poly(alkylene

terephthalate).

19. The composition of any of claims 17-18, wherein the polyester comprises a poly(butylene terephthalate), a poly(ethylene terephthalate), or any combination thereof.

20. The composition of any of claims 17-19, wherein the polyol comprises at least three hydroxyl groups.