DE4120919C2 - Membrane, in particular gas separation or pervaporation membrane - Google Patents

Description

The invention relates to a membrane based on a gas-permeable Membrane polymer, this polymer itself and a process for the preparation from that. The membrane according to the invention is in particular a Gas separation or pervaporation membrane.

For the separation of gas mixtures and / or gas mixtures consisting of gases and vapors of organic solvents Often one uses dense films of organic Plastics that act as a membrane. One differentiates between 2 types of membranes, namely the integral asymmetric membranes and the composite membranes.

Integral asymmetric membranes consist of a Polymer or a mixture of compatible Polymers that by a Phase inversion process into the shape of oneself carrying and supporting membrane is brought or become. This makes it possible to have a very thin, stable Separating layer of the polymer or the polymer mixture to receive.

Composite membranes are made up of thin films suitable, organic or inorganic carrier materials be applied. The support materials must on the one hand have a high gas permeability and On the other hand, be incorporated into modules and dimensionally stable. For example, as organic support materials microporous polysulfone, polypropylene, Polyvinylidene fluoride or polyetherimide PVDF support used. As inorganic support materials were So far, for example, microporous glasses or microporous Aluminum oxides used. Both the inorganic as well as the organic support materials can be used to smooth the surface with a very thin Film of a particularly good gas-permeable polymer (eg. Poly (dimethylsiloxane) or poly (trimethylsilylpropyne) be equipped.

The actual release layer will be on the surface of the treated or untreated microporous carrier applied, aimed for the purpose of large gas flows is a thin film of the release polymer applied.

For example, as known separation polymers used: poly (dimethylsiloxane), poly (4-methyl-1-pentene), Ethylcellulose, natural rubber, LD-polyethylene and cellulose acetate.

In EP-A 02 66 698, for example, fluoroacrylates while in US-A 46 36 229 Fumaric acid esters are claimed, the better rivers and / or release values (pO₂ / pN₂) than the previously known Have polymers. A method of manufacture of thin films and their chemical fixation however, they are not mentioned on suitable carriers.

In EP-A 01 81 772, the production is very thin Films of brominated poly (phenylene oxide) on with poly (di-methylsiloxane) filmed microporous polysulfone carriers described. The applied release layer consists of a glassy polymer and is therefore suitable for organic solvent vapors not suitable. also the gas flows are low.

Furthermore, EP-A 02 56 530 describes a very good gas-permeable composite membrane of cross-linked Poly (4-methyl-1-pentene) and poly (phenylene oxide). The the However, gas separation effecting polymers are not for the separation of polar organic vapors suitable. A chemical compound of the release layer with the carrier film is not mentioned in this document.

For other separation problems, such as in the separation of Methanol from a mixture of C₄ and C₅ hydrocarbons and methyl ethers in the production of MTBE (methyl tert-isobutyl ether and TAME (tertiary amyl methyl ether), are already so-called Pervaporation membranes have been proposed, compare in this regard, for example, AIChE Symp. Ser. 85 (1989) 272, 89 to 92. Furthermore, in US-PS 47 74 365 different membranes, for example, from cellulose acetate, polyvinyl alcohol, polysulfone, Silicone rubber and polysubstituted acetylenes as such Pervaporation membranes have been recommended.

The object of the present invention is to provide a membrane which in particular as a gas separation membrane or pervaporation membrane can be used, or a polymer with good release properties, in particular gas separation properties, wherein the polymer must be able to be processed into very thin films.

This problem is solved by the teaching of the claims.

The membrane of the invention is characterized in particular by the Recurring unit of the general shown in the claims Formula (I).

The radicals R¹ and R² may be a linear, branched or mean cyclic C₁-C₁₈ hydrocarbon radical. It is in the simplest case, an alkyl radical. This hydrocarbon radical however, can occur both in the main chain and in a side chain have a C = C double bond. Is this C = C double bond in the main chain, then it is preferable around a terminal double bond. To the mentioned C₁-C₁₈ hydrocarbon radicals thus also include alkenyl radicals.

This hydrocarbon radical can also be one or more O- or Have N atoms, so that this hydrocarbon radical and those may have functional groups resulting from the combination of C, O and N atoms. These include, for example Ethers (-C-O-C-), imines (-C-NH-C-), esters (-C-C [O] O-C-) and amines (-C-C- (NH2) C-). Per radical R¹ or R² can 1 to 10 N and / or O atoms are present.

In other words, this hydrocarbon residue sets one aliphatic radical having one or more alkyl moieties. If several alkyl units are present, then they can be functional Groups (ethers, imines, esters) or by a C = C double bond be connected to each other. It is also possible to have one or more Hydrogen atoms of the alkyl moieties through an amino or Hydroxy group (amine, alcohol) to replace.

This hydrocarbon may also be a phenyl or naphthyl group carry. In the simplest case exists  the hydrocarbon radical from a methyl group substituted by a phenyl group. This then gives the benzyl group.

Even chiral hydrocarbon radicals can be used, for example, an ethyl group which is in the 1-position by a phenyl or naphthyl radical.

The radical R² can also be a C₁-C₁₈-alkyl radical, which by a halogen atom, in particular chlorine, is substituted. As typical Representative is called the 2-chloroethyl.

The radicals R¹ and R² can also be an aromatic Hydrocarbon radical mean by one or more C₁-C₆-alkyl radicals may be substituted. As an example of this is the Phenyl radical and called the Trimethylphenylrest.

The radicals R¹ and R² may further aromatic and non-aromatic Heterocycles mean.

The radicals R¹ and R² can - as already described above - in the Main chain (there especially terminal) or in a side chain having C = C double bonds. The invention Polymer or the membrane according to the invention contains such radicals R¹ and R² preferably in a concentration of 3 to 100 mol%, preferably 100 mol% or 3 to 10 mol%. The number The double bond affects the later described cross-linking.

Such C = C double bonds containing units can still after the polymerization be introduced into the polymer. This further possibility a group suitable for cross-linking in the polymer to introduce these is by a chemical Reactively incorporate reaction on the polymer according to the following Formula (2)

CH₂-C (O) _m -O- (CH₂) _n -P →HO- (CH₂) _n -P →Cl-R-CH = CH₂-HClCH₂ =
CH-RO- (CH₂) _n -P (2)

P = polymer chain, m = 0 or 1, n = 1-18.

The radical R denotes a hydrocarbon radical (in particular alkyl radical) having 1 to 9 and in particular 2 to 9 carbon atoms. This radical R may also include a carbonyl group. In the latter case, the following compounds are then also included: CH₂ = CH- (CH₂) _n-1 -C (O) -O- (CH₂) _n -P. The radical R is then the moiety - (CH₂) _n-1 -C (O) -, the carbonyl group forms an ester group with the attached O atom.

The subsequent introduction of the reactive groups has the advantage increase the shelf life of the base polymer.

The membranes according to the invention thus include those which on the one hand, no groups suitable for cross-linking, in particular Have double bonds, and also those which such Crosslinking have suitable groups. To the invention Membranes also include those obtained by cross-linking these Groups or double bonds were obtained.

With regard to the molecular weight, it is generally true that from a certain molecular weight, usually greater than 50 000 g / mol, the gas separation properties do not change anymore. This also applies to lower grades the cross-linking.

From the above polymers, with or without reactive Groups can work on smooth surfaces of glass, metal or Plastics or microporous substrates (eg microporous Flat membranes or hollow fibers) consisting of Polytetrafluoroethylene, polypropylene, polysulfone, polyetherimide or the like, by the usual methods of making films become. The less viscous solution Procedures are referred to in the literature as "meniscus coating "or" dip coating ", which in the present Trapped particularly thin films produced from 0.5 microns to 10 microns can be. For thicker films from 10 μm to 200 μm Order from concentrated polymer solutions by means of Knife blade or glass rod preferred. For smaller membrane pieces can also evaporate a 5- to 10% Polymer solution in a closed chamber by rinsing be used with nitrogen or argon as protective gas.

The membranes of the invention usually have a thickness of 0.5 to 200 microns. The polymer of the general Formula (I) for the preparation of the inventive Membrane is conveniently obtained by free radical Copolymerization of N-substituted maleimides (m) with Vinyl ether (s). The maleimide and / or the vinyl ether may also consist of more than one monomer of the respective type. In other words, they can be different substituted maleimides and vinyl ethers are used become.

The maleimides and vinyl ethers are preferably used in a molar ratio of 1: 1.

The polymerization produces alternating copolymers. Polymers of this type are known (US Pat. No. 2,342,295, Polym. Mat. Sci. Closely. 61, 502-506 (1969).

Maleimide thus polymerizes a vinyl ether alternately via a charge transfer mechanism.

It is also possible to use the vinyl ether in excess, such that the maleimide (m) accounts for 40 to 60% of (n). In general, however, m should be = n, because then one obtains a better defined polymer at higher conversion.

The preparation of the polymer used can be carried out as follows (general procedure):
Dissolve 0.1 mol of maleimide in a halogenated hydrocarbon solvent and provide with a spatula tip solid NaHCO₃. The mixture is stirred for 1 h at room temperature and mixed with 0.1 mol of vinyl ether. It works under argon in an oxygen-free atmosphere. 0.001 to 0.005 mol of free radical generator are added and polymerization is carried out at 20 to 60.degree. C. for 3 to 16 hours. It precipitates in a suitable non-solvent and is used several times for cleaning. The polymer is obtained in 60 to 90% yield with _w of 100,000 to 800,000 g / mol ( _w / _n 2.2 to 3.0). The solvent used is preferably 5 mol% of AIBN (azobisisobutyronitrile). It is preferably 4 h at 40 ° C polymerized.

The reproducibility and controllability of radical polymerization can be achieved by the addition of  Acid scavengers and in particular solid sodium bicarbonate be significantly improved to the reaction solution. Thereby Acid traces are effectively and easily removed that else to the cationic homopolymerization of the vinyl ether component as a competitive reaction.

The above-mentioned thin polymer films of 0.5 to 10 microns are best prepared from the above polymers, which are precrosslinked in solution. Then you can apply the polymer to microporous supports and then continue to cross-link. The preferred application methods are dip coating or application by means of a foam impregnated in a polymer solution foam strip. The solution usually has a concentration from 0.1 to 10%.

When applied to a RTV crosslinkable silicone film (eg VP 7660, Wacker Chemie), which is still not complete vulcanized, chemical bonds arise between the applied polymer and the silicone film. this leads to to a special stability of the composite membrane, the thus also a use in the separation of organic Vapors from solvent and in the pervaporation permits.

By the inventively used -R-CH = CH₂- Units it is also possible to connect to PDMS movies by covalent bonds. The permanent one Fixation leads to increased stability of the very thin Polymer film.

By said, further thermal crosslinking of Polymer film on the support, the polymer is insoluble and thus resistant to organic solvent vapors and solvent mixtures.

The above-mentioned, incomplete crosslinking or precrosslinking leads to higher molecular weights and larger M _w / M _n values and thus to a broader molecular weight distribution. This makes it possible to draw thin, homogeneous polymer films. Thus, according to the invention, it is also possible to obtain thin polymer films which are not supported by or applied to a support.

Example 1

12.8 g (0.065 mol) of N-acetoxypropylmaleimide (preparation see Polym. Mat Sci. Closely. 61, 502-506 (1969)) were published in Dissolved 80 ml of dry dichloromethane and with a Spatula tip of dry sodium bicarbonate. It was stirred for 1 h at room temperature with a magnetic stirrer. It was mixed with 19.33 g (0.065 mol) of octadecyl vinyl ether (Polyscience) and 100 mg / AIBN and 3 times Evacuate and aerate with argon the oxygen away. It was stirred for 4 h at 60 ° C bath temperature heated to reflux and the reaction solution in 1.8 l Like methanol. The polymer was washed two more times Dissolved dichloromethane and precipitated with methanol. It was at Dried at oil-pump vacuum at 30 ° C and 19.2 g (60%) Obtained polymer.

GPC: IR: M _w = 3.75 × 10⁵ (g / mol) OH: - cm ^-1 M _w / M _n = 2.7 Imide: 1695 (v) cm ^-1 1765 (w) cm ^-1 1 V = 0.87 (dl / g) in THF Ester: 1735 (v) cm ^-1 T _G = 30 ° C

0.7 g of the polymer was dissolved in 7 ml of carbon tetrachloride dissolved and in a closed chamber on a Teflon film rinsed to dryness with an argon stream. It a 50 μm thick film was obtained. With a vacuum apparatus were the gas permeation data with pure gases certainly.

pN₂ = 3.2 × 10 ^-8 pO₂ = 9.0 × 10 ^-8 pO₂ / pN₂ = 2.8 pCO₂ = 43 × 10 ^-8 pCO₂ / pN₂ = 13 (p is given in [m³.m / m².hbar])

example 2

18.3 g of polymer from Example 1 were dissolved in 680 ml of toluene / isopropanol (1: 1) and treated with 50 ml of 15% hydrochloric acid. The mixture was heated to reflux for 4 h, concentrated to half by rotary evaporation and precipitated in 1.8 l of methanol. It was precipitated twice from dichloromethane with methanol and the residue dried in an oil pump vacuum:
Yield: 14.4 g (86%).

GPC: IR: M _w = 3.01 × 10⁵ (g / mol) OH: 3420 cm ^-1 M _w / M _n = 2.7 Imide: 1690 (v) cm ^-1 1765 (w) cm ^-1 IV = 0.79 (dl / g) in THF Ester: - (v) cm ^-1

example 3

13.6 g of polymer from Example 2 were azeotropically dehydrated with toluene and dissolved in 75 ml of dry toluene. Under argon blanketing gas and stirring, 4 ml of dry pyridine and 10.0 ml of 10-undecenoyl chloride dissolved in 5 ml of dry toluene were added dropwise. The mixture was stirred at 40 ° C. for 4 h and precipitated in 1.5 l of methanol. It was precipitated twice from dichloromethane with methanol and dried in an oil pump vacuum:
Yield: 16.3 g (88%).

GPC: IR: M _w = 5.23 x 10⁵ (g / mol) OH: - cm ^-1 M _w / M _n = 2.82 Imide: 1695 (v) cm ^-1 1765 (w) cm ^-1 IV = 0.76 (dl / g) in THF Ester: 1735 (v) cm ^-1 Vinyl: 1635 (w) cm ^-1 T _G = 23 ° C

0.6 g of the polymer was dissolved in 6 ml of i-octane and dissolved a microporous Polyetherimidträger in a closed Flushed chamber with an argon stream to dryness. A 108 μm thick polymer film was obtained. The gas permeation properties were with pure gases in a vacuum apparatus determined without dissolving the polymer from the carrier.

pN₂ = 4.6 × 10 ^-8 pO₂ = 12 × 10 ^-8 pO₂ / pN₂ = 2.6 pCO₂ = 73 × 10 ^-8 pCO₂ / pN₂ = 16 (p is given in [m³.m / m².hbar])

example 4

31.5 g (0.16 mol) of N-Acetoxypropylmaleinimid were dissolved in 250 ml of dichloromethane and treated with a spatula tip of dry sodium bicarbonate. It was stirred for 1 h at room temperature with a magnetic stirrer. There were added 25.6 g (0.16 mol) of vinyl 2- (2-ethoxy-ethoxy) ethyl ether (Polysciende) and 0.5 g of AIBN and after three evacuations and aerating with argon for 6 h at 60 ° C bath temperature stirred under inert gas. It was precipitated in 3.5 l of hexane and reprecipitated twice from dichloromethane with hexane. It was dried at 30 ° C in an oil pump vacuum;
Yield: 43.1 g (75%).

GPC: IR: M _w = 4.3 × 10⁵ (g / mol) OH: - cm ^-1 M _w / M _n = 2.53 Imide: 1690 (v) cm ^-1 1765 (w) cm ^-1 1 V = 0.62 (dl / g) in THF Ester: 1730 (v) cm ^-1 T _G = 10 ° C

0.7 g of the polymer were dissolved in 7 ml of THF and in a closed chamber on a microporous PVDF membrane rinsed to dryness with an argon stream. It was obtained a 65 micron thick film. The gas permeation data were determined in a vacuum apparatus without the film to release from the carrier.

pN₂ = 3.5 × 10 ^-⁹ pO₂ = 11 × 10 ^-⁹ pO₂ / pN₂ = 3.3 pCO₂ = 140 × 10 ^-⁹ pCO₂ / pN₂ = 40 (p in [m³.m / m².hbar])

example 5

35.7 g of polymer from Example 4 were mixed with 1 l of toluene / isopropanol and 100 ml of 15% hydrochloric acid and heated under reflux for 3 h. The solvent was removed almost to the residue on a rotary evaporator. The residue was dissolved in methanol and treated with methanol / 25% ammonia (1: 1) to pH 9. It was removed on a rotary evaporator to the residue. The residue was dissolved in acetone, centrifuged and again evaporated to residue. It was dried at 30 ° C in an oil pump vacuum;
Yield: 29.2 g (92%).

ih:
OH: 3850 (m) cm ^-1
Imide: 1690 (v) cm ^-1
1765 (w) cm ^-1
Ester: - cm ^-1

example 6

1.89 g (6 mmol OH groups) of anhydrous polymer from Example 5 were dissolved in 35 ml of dry acetone, and under argon atmosphere, 0.53 ml of dry pyridine and 1.46 ml (6.6 mmol) of 10-undecenoyl chloride were dissolved added dropwise in 5 ml of dry acetone. It was stirred for 6 h at 60 ° C bath temperature under argon and precipitated in 800 ml of methanol. It was dissolved twice in dichloromethane and precipitated with methanol. The precipitated polymer was dried at 30 ° C in an oil pump vacuum;
Yield: 2.4 g (84%).

GPC: IR: M _w = 5.70 × 10⁵ (g / mol) OH: - cm ^-1 M _w / M _n = 3.7 Imide: 1690 (v) cm ^-1 1765 (w) cm ^-1 IV = 1.0 (dl / g) in THF Ester: 1730 (v) cm ^-1 Vinyl: 1635 (w) cm ^-1 T _G = 7 ° C

0.7 g of the polymer was dissolved in 7 ml of carbon tetrachloride dissolved and in a closed chamber on a microporous Polyetherimidträger given. It was with a Purged argon stream to dryness. The 46 μm thick polymer film was in a vacuum apparatus on the Gaspermeationseigenschaften tested.

pN₂ = 2.0 × 10 ^-8 pO₂ = 5.4 × 10 ^-8 pO₂ / pN₂ = 2.7 pCO₂ = 49 × 10 ^-8 pCO₂ / pN₂ = 24 (p in [m³.m / m².hbar])

example 7

1.6 g of a polymer prepared according to Example 3 (M _w / M _n = 2.5, IV = 0.53 dl / g) were dissolved in 16 ml of i-octane and mixed with 16 mg of methylhydrodimethylsiloxane copolymer (ABCR No. PS 123). Under an argon atmosphere, 16 μl of platinum catalyst solution (ABCR No. PCO72) were added and the mixture was stirred at 50 ° C. for 2 h. The resulting solution (M _w / M _n = 3.4, IV = 0.65 dl / gm) was stable in the refrigerator for a few days.

example 8

A foam strip (25 × 3 × 0.5 cm) was washed several times Washed i-octane, dried and put in a holder clamped about 3/4. A prepared according to Example 7 Solution was diluted to 2 or 4% and the foam strip was soaked drip-free:

• a) A microporous polyetherimide support (Q 300 m³ / m 2 · h · bar) was three times with a 24% solution (see above) impregnated foam strips over painted and 1 h at Cross-linked at 80 ° C. The gas permeation data is in Tables 1 and 2 summarized.
• b) A polyetherimide carrier coated with a silicone film (Q₀₂ ≈ 1.5 m³ / m² ·hbar; pO₂ / pN₂ = 2.1) three times with one soaked in a 4% solution (see above) Foam strips overcoated and 1 h at Cross-linked at 80 ° C. The gas permeation data are in tables 1 and 2 summarized.

example 9

2.0 g of a polymer prepared according to Example 6 (M _w / M _n = 2.87, IV = 1.1 dl / g) were dissolved in 20 ml of carbon tetrachloride and treated with 20 mg of methylhydrodimethylsiloxane copolymer (ABCR No. PS123) , Under an argon atmosphere, 20 μl of platinum catalyst solution (ABCR No. PCO72) was added and stirred at 80 ° C. for 20 minutes. The resulting solution (M _w / M _n = 5.7, 1.0 dl / gm) remained stable in the refrigerator for a few days.

example 10

As described in Example 8, a foam strip was with a solution diluted to 2% Example 9 soaked and applied to:

• a) microporous polyetherimide support (see Example 8a))
• b) silicone film-coated polyetherimide support (see Example 8b)).

The gas permeation data of a) and b) are in Tables 1 and 2 summarized.  

Table 1

Table 2

example 11

The membranes of Example 8a, 10a) and a 6.8 μm PDMS membrane for comparison with 2% by volume and 7% by volume of methanol vapor in an argon atmosphere applied. The selectivity pMeOH / PAr was using a mass spectrometer online at a permeate pressure <3 mbar determined directly. The selectivity pMeOH / pN₂ gives by pMeOH / pAr × pAr / pN₂ assuming that pAr / pN₂ is not changed by the methanol vapor. Similarly was traversed with 3.37 vol .-% and 10 vol .-% n-hexane vapor.

The values found are summarized in Table 3 and show that membranes 8a) and 10a) perform significantly better separation of methanol vapors than the co-tested PDMS standard membrane. The membrane 8a) also shows a better separation of n-hexane vapors. Table 4 summarizes the flows of the membranes.

Table 4

Rivers of the membranes

example 12

9.5 g (30 mmol OH groups) dried polymer from Example 5 were dissolved in 100 ml of THF and under N₂ inert gas with 2.9 ml (36 mmol) of pyridine. There were 0.67 ml (3 mmol) 10-undecenoyl chloride, dissolved in 10 ml of dry THF, slowly dropwise. After one hour stirring at RT, 4.5 ml (60 mmol) Acetic anhydride dissolved in 10 ml of dry THF slowly added dropwise and stirring was continued at RT for 16 h.

It was precipitated in n-hexane, reprecipitated several times from dichloromethane in n-hexane, washed with water and dried in an oil pump vacuum at 30 ° C;
Yield: 10 g.

GPC: IR: M _w = 9.3 × 10⁴ (g / mol) OH: - cm ^-1 M _w / M _n = 1.8 Imide: 1690 (v) cm ^-1 1765 (w) cm ^-1 1 V = 0.19 (dl / g) in THF Ester: 1730 (v) cm ^-1 Vinyl: 1635 (w) cm ^-1 T _G = 6 ° C

example 13

9.5 g of a polymer prepared according to Example 12 (M _w / M _n = 1.8, IV = 0.19 dl / g) were dissolved in 95 ml of carbon tetrachloride and treated with 0.95 g of methylhydro-dimethylsiloxane copolymer (ABCR no PS123). Under an argon atmosphere, 95 μl of platinum catalyst solution (ABCR No. PCO72) were added and the mixture was stirred at 80 ° C. for 300 minutes. The resulting solution (M _w / M _n = 7.3, IV = 0.27 dl / gm) remained stable in the refrigerator for a few days.

7 ml of the THF solution were placed in a closed chamber on a Flush teflon plate with an argon stream to dryness. It was obtained a 113 micron thick film. The gas permeation data were determined in a vacuum apparatus.

p N₂ = 4.1 × 10 ^-9 m³ / m.sup.2.h.bar
p O₂ = 14 × 10 ^-9 m³ / m² · h · bar
p CO₂ = 170 × 10 ^-9 m³ / m².h.bar

pO₂ / p N₂ = 3.2
pCO₂ / pN₂ = 40.

example 14

A foam strip (25 x 3 x 0.5 cm) was washed several times with carbon tetrachloride washed out, dried and in a holder about Clamped 3/4. A solution prepared according to Example 13 was opened 4% diluted and the foam strip was thus drip-free soaked.

A microporous Polyetherimidträger (Q ≈ 300 m³ / m² · hbar) was several times with a foam strip soaked in 4% solution (see above) coated and cross-linked at 80 ° C for 1 h.

The gas permeation data of the thin-film composite membrane was measured with measured a vacuum apparatus. The layer thickness of Composite membrane became from the permeation data of the thick film calculated in Example 13.

a) pN₂ = 1.0 × 10 ^-3 m³ / m 2 · h · bar pO₂ = 3.5 × 10 ^-3 m 3 / m 2 · hbar pO₂ / pN₂ = 3.3 pCO₂ = 35 × 10 ^-3 m 3 / m 2 · hbar pCO₂ / pN₂ = 35   b) pN₂ = 0.43 × 10 ^-3 m 3 / m 2 · h · bar @ pO₂ = 1.4 × 10 ^-3 m³ / m 2 · hbar pO₂ / pN₂ = 3.2 pCO₂ = 16 × 10 ^-3 m³ / m 2 · hbar pCO₂ / pN₂ = 38

Calculated film thickness = 4.2 μm for a) and 9.7 μm for b).

example 15

The composite membranes prepared according to Example 14 were in the pervaporation tested. Table 5 summarizes the results.

It applies

β = Perm. Konz./Zulauf-Konz.

Claims (11)

1. Membrane, in particular gas separation membrane or pervaporation membrane, based on a polymer of the following repeating unit of the general formula (I) wherein
R¹ and R², which may be the same or different, are a linear, branched or cyclic C₁-C₁₈ hydrocarbon radical which may have a C = C double bond arranged in the main chain or in a side chain, in the main or side chain or as lateral Substituents may have one or more O or N atoms and which may be substituted by a phenyl or naphthyl radical, wherein in the case of the radical R², the C₁-C₁₈ hydrocarbon radical may also be substituted by a halogen atom,
an aromatic hydrocarbon radical which may be substituted by one or more C₁-C₆-alkyl or alkylene radical, and
an aromatic or non-aromatic heterocycle,
m is n and the radical R¹ or R² of a repeating unit of the general formula (I) may be identical or different from the radical R¹ or R² of a further repeating unit of the general formula (I),
wherein the optionally present in the radicals R¹ and / or R² (s) double bond (s) may be crosslinked (can). 2. Membrane according to claim 1, characterized in that the radical R¹ is a straight-chain C₁-C₁₀-, C₁₂-, C₁₄-, C₁₆- and C₁₈-alkyl radical,
a branched C₁-C₁₀, C₁₂, C₁₄, C₁₆ and C₁₈-alkyl radical, in particular an iso-C₄, iso-C₅- and iso-C₁₀-alkyl radical, an oleyl and 2-propenyl radical,
a chiral (R) - (+) - 1-phenylethyl, (S) - (-) - 1-phenylethyl, (R) - (+) - 1-cyclohexyl, (R) - (-) - 1 Cyclohexyl, (R) - (+) - 1- (1-naphthyl) ethyl and (S) - (-) - 1- (1-naphthyl) ethyl,
a cyclic C₃-, C₅-, C₆-, C₈-, C₁₂-alkyl radical,
an ester radical of the formula - (CH₂) ₃-OR ', wherein
R 'is H, oleyl, 6-hexenoyl, 10-decenoyl and CO-R ", wherein
R '' denotes the above-mentioned straight-chain and branched alkyl radicals,
a methoxyethoxypropyl radical and
a phenyl and trimethylphenyl radical means and
R² is a straight-chain C₁-C₁₈-alkyl radical,
a branched C₁-C₁₈-alkyl radical, in particular an iso-C₄- and iso-C₁₀-alkyl radical,
a 2-chloroethyl radical,
a methoxyethyl radical and a radical of the following formula - ((CH₂) ₂-O) _n -R''worin
n stands for 1 to 10, and
R '''is CH₃ and CH₂-CH₃. 3. Membrane according to claim 1 or 2, characterized in that 3 to 100% and especially 3 to 10 or 100% of the radicals R¹ and / or R² have a C = C double bond. 4. Membrane according to one of claims 1 to 3, characterized in that at least one of the radicals R¹ and R² is a -RCH = CH₂ unit, wherein R is a C₂-C₉ hydrocarbon radical means a carbonyl group can have. 5. Membrane according to one of claims 1 to 4, obtainable thereby, in that a polymer of the general formula (I) in which at least one of R¹ and R² is a C = C double bond has, in particular in the dissolved state, a treated or untreated carrier known per se and then the double bond (s) cross-linked. 6. Membrane according to claim 5, characterized in that the Pre-crosslinked polymer in solution and then after application to the carrier further crosslinked, especially thermally. 7. Membrane according to one of claims 1 to 6, characterized characterized in that the polymer of general formula (I) as Film is present with a thickness of 0.5 to 200 microns. 8. Polymer of the general formula (I) according to one of the claims 1 to 4. 9. A process for producing a membrane according to any one of claims 1 to 7, characterized in that one or more N-substituted maleimide (s) of the general formula (II) wherein
the radical R¹ has the meanings given above,
with one or more vinyl ether (s) of the general formula (III) CH₂ = CH-O-R² (III) in which
R² has the meanings given above,
polymerized free-radically and then processed into a film, wherein in particular an acid scavenger, in particular solid NaHCO added to the polymerization. 10. The method according to claim 9 for the preparation of a by a Supported membrane, characterized in that one the polymer obtained, in particular dissolved in a solvent, applied to a per se known carrier and then, if it for crosslinking suitable groups, in particular C = C double bonds cross-linked. 11. The method according to claim 10, characterized in that one the groups suitable for cross-linking after performance the polymerization is introduced into the resulting polymer.