CN115216128A - High-flexibility and high-antibacterial-property biodegradable polylactic acid material and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of biodegradable plastics, and discloses a high-flexibility and high-antibacterial-property biodegradable polylactic acid material which is prepared by combining the following materials in parts by weight: the mass ratio of PLA to PBAT is 9 (0.5-1); the mass ratio of PLA to chloroform is 1: (40-4); the cardanol oil content is 5-6% of the mass of PLA and PBAT, and Al ₂ O ₃ The content of the nano particles is 1 to 1.5 percent of the mass of the PLA and the PBAT. According to the high-flexibility and high-antibacterial-property biodegradable polylactic acid material prepared by the invention, the addition of cardanol as a plasticizer improves the ratio of PLA to PLAThe PBAT composite film has the advantages of mechanical strength and heat resistance, increased tensile strength and improved heat resistance.

Description

A kind of high flexibility, high antibacterial bio-based degradable polylactic acid material and its preparation method

technical field

The invention relates to the technical field of biodegradable plastics, in particular to a bio-based degradable polylactic acid material with high flexibility and high antibacterial properties and a preparation method thereof.

Background technique

The development and utilization of polymer materials prepared from petroleum will be strictly controlled. Therefore, biodegradable materials have gradually highlighted their advantages. Among them, polylactic acid (PLA) is prepared from renewable resources-starch, which not only has the advantages of good biodegradability and high biocompatibility, but also is simple and easy to obtain. It has excellent mechanical properties and has broad application prospects in the field of general plastics and medical packaging. However, the high brittleness, poor toughness and thermal stability of PLA limit its application in flexible packaging films.

Blending PLA with bio-based polymers is a common means to improve the properties of membrane materials. Among them, polyoxalic acid (PBAT) is an important alternative to traditional polymers due to its high flexibility and low cost. Way. However, due to the difference in solubility between the two, PBAT often cannot be uniformly dispersed into the PLA matrix. Adding plasticizer/compatibilizer to the blend can effectively improve the problem of uneven mixing of the two. Among them, cardanol is prepared from cashew nut shell and is a green, low-cost plasticizer. It can not only significantly improve the compatibility of PLA and PBAT, but also has good biodegradability, making it the first choice for preparing biodegradable materials. . And Al ₂ O ₃ nanoparticles have excellent metallic properties and can be used to improve the interaction between material interfaces.

With the vigorous development of the takeaway industry, the excessive use of various plastic tableware and food packaging bags has also accelerated the white pollution of the environment. At the same time, various food packaging bags that do not meet national standards have also caused a series of food safety problems. At present, the development of fully biodegradable composite flexible membrane materials with excellent antibacterial properties is an important means to improve food safety and reduce environmental pollution. Therefore, the present invention provides a bio-based degradable polylactic acid material with high flexibility and high antibacterial properties and a preparation method thereof.

SUMMARY OF THE INVENTION

(1) Technical problems solved

In view of the deficiencies of the prior art, the purpose of the present invention is to provide a highly flexible, highly antibacterial bio-based degradable polylactic acid material, the bio-based degradable polylactic acid material includes: PLA, PBAT, cardanol, Al ₂ O ₃ Combination of nanoparticles and chloroform; by adding cardanol, the compatibility of PBAT and PAL can be significantly improved, and by adding nano-Al ₂ O ₃ particles to enhance the interfacial effect of the material, the final product has excellent toughness and good heat resistance. Antibacterial biodegradable polylactic acid plastic.

(2) Technical solutions

To achieve the above object, the present invention provides the following technical solutions:

A bio-based degradable polylactic acid material with high flexibility and high antibacterial properties is composed of materials in the following proportions: the mass ratio of PLA to PBAT is 9:(0.5-1); the mass ratio of PLA to chloroform is 1: (40-4); the content of cardanol oil is 5%-6% of the mass of PLA and PBAT, and the content of Al ₂ O ₃ nanoparticles is 1%-1.5% of the mass of PLA and PBAT.

Wherein, the PLA includes, but is not limited to, the product of Guangzhou Bijia Materials Co., Ltd. with the brand name of 301P; the brand of Anhui Fengyuan Futailai Polylactic Acid Co., Ltd. is FY204; the product of the American Natureworks Company with the brand of 2003D; preferably the American Natureworks The company's PLA product, the grade is 2003D.

Wherein, the PBAT includes, but is not limited to, the product of Guangdong Shuntian New Materials Co., Ltd. with the trade mark of 3130M; Xinjiang Lanshan Tunhe Polyester Co., Ltd. with the trade mark of TH801T; Zhengzhou Jinyuandong Technology Co., Ltd. with the trade mark of 5582; It is preferably the PBAT product of Xinjiang Lanshan Tunhe Polyester Co., Ltd., with the brand name TH801T.

Wherein, the plasticizer is cardanol, which is a natural green plasticizer, which solves the problems of poor compatibility between PBAT and PLA and that PBAT cannot be uniformly dispersed into the PLA matrix.

Wherein, the reinforcing agent is Al ₂ O ₃ nanoparticles, which solves the problems of poor toughness and high brittleness of PLA.

Wherein, the tensile strength of the flexible, highly antibacterial bio-based degradable polylactic acid material is preferably 50Mpa or more, preferably 52Mpa or more, more preferably 54Mpa, still more preferably 56Mpa, and still more preferably 58Mpa or more.

Wherein, the elongation rate of the flexible and highly antibacterial bio-based degradable polylactic acid material is preferably 120% or more, preferably 130% or more, more preferably 140% or more, and even more preferably 150% or more.

The invention discloses a preparation method of the above-mentioned high flexibility and high antibacterial bio-based degradable polylactic acid material. The PLA and PBAT particles are placed in an oven at 50 DEG C to dry for 6 hours, and a certain mass of Al ₂ O ₃ nanoparticles and a certain mass of Al 2 O 3 nanoparticles are weighed. Cardanol was ultrasonically dispersed in chloroform solution, and PLA, PBAT, and cardanol were added to chloroform according to the ratio and stirred continuously for 4-5 hours. The film-forming solution was transferred to a glass plate to make it evenly distributed, and dried for 24 hours to solidify.

Wherein, the ultrasonic time is 3-5min.

Wherein, the ultrasonic time is 5-7min.

Wherein, the ultrasonic time is 7-9min.

Wherein, the mixing temperature of the PLA, PBAT and cardanol is 23-25°C.

Wherein, the drying and curing temperature is 23-25°C.

(3) Beneficial effects

Compared with the prior art, the present invention provides a highly flexible, highly antibacterial bio-based degradable polylactic acid material and a preparation method thereof, which have the following beneficial effects:

1. The bio-based degradable polylactic acid material with high flexibility and high antibacterial properties prepared by the present invention improves the mechanical strength and heat resistance of the PLA and PBAT composite film by adding cardanol as a plasticizer, and increases the tensile strength of the material. , the heat resistance is improved.

2. The present invention can effectively improve the water vapor transmission rate and the contact angle with water of the composite membrane by adding Al ₂ O ₃ nanoparticles as a reinforcing agent, and at the same time, the contaminating bacteria of the material appear in the highest inhibition zone.

Detailed ways

The PLA described in the following examples is the PLA product of U.S. Natureworks company, and the trade name is 2003D; the PBAT is the PBAT product of Xinjiang Lanshan Tunhe Polyester Co., Ltd., and the trade name is TH801T.

A highly flexible and highly antibacterial bio-based degradable polylactic acid material, the high flexibility and high antibacterial bio-based degradable polylactic acid material is prepared from polylactic acid (PLA), polyoxalic acid (PBAT), cashew nut Phenol oil, alumina (Al2O3) nanoparticles, chloroform as solvent;

The mass ratio of PLA to PBAT is 9:(0.5-1); the mass ratio of PLA to chloroform is 1:(40-4); the cardanol oil content is 5%-6% of the mass of PLA and PBAT, and Al2O3 nanoparticles The content is 1%-1.5% of the mass of PLA and PBAT.

The average molecular weight of the PLA is 205000-207000 g/mol.

The average molecular weight of the PBAT is 141500-142000 g/mol.

The Al2O3 particle size is 30-40nm.

The cardanol density is 0.97-0.98 g/cm3.

The chloroform is a film-forming solvent for PLA, PBAT, cardanol oil, and Al2O3 nanoparticles.

Example 1

A highly flexible, highly antibacterial bio-based degradable polylactic acid material, the preparation method of which comprises the following steps:

(1) Weigh 3.6g PLA, 0.4g PBAT, 0.04g Al ₂ O ₃ nanoparticles, and 0.2g cardanol.

(2) The Al ₂ O ₃ nanoparticles and cardanol in step (1) were added to 100 ml of chloroform solution for ultrasonic dispersion for 3 min.

(3) PLA, PBAT and cardanol are added to the mixed solution in step (2), and magnetically stirred at 23° C. for 4 hours until all the raw materials are dissolved.

(4) Transfer the solution obtained in step (3) to a glass plate to make it evenly dispersed, and dry at 25° C. for 24 hours to solidify the film material.

(5) Carry out oxygen and moisture permeability tests on the obtained membrane materials, and the experimental data are shown in Table 1.

Table 1 Oxygen permeability and moisture permeability test of the obtained membrane materials

Example 2

(1) Weigh 7.2g PLA and 0.8g PBAT, 0.11g Al ₂ O ₃ nanoparticles, and 0.41g cardanol.

(2) The Al ₂ O ₃ nanoparticles and cardanol in step (1) were added to 200 ml of chloroform solution for ultrasonic dispersion for 5 min.

(3) PLA, PBAT and cardanol are added to the mixed solution in step (2), and magnetically stirred at 25° C. for 5 hours until all the raw materials are dissolved.

(4) Transfer the solution obtained in step (3) to a glass plate to make it evenly dispersed, and dry at 25° C. for 24 hours to solidify the film material.

(5) Carry out oxygen permeability and moisture permeability tests on the obtained membrane material, and the experimental data are shown in Table 2

Table 2 Oxygen permeability and moisture permeability test of the membrane materials prepared

Example 3

(1) Weigh 18g PLA and 2g PBAT, 0.25g Al ₂ O ₃ nanoparticles, and 0.83g cardanol.

(2) The Al ₂ O ₃ nanoparticles and cardanol in step (1) were added to 500 ml of chloroform solution for ultrasonic dispersion for 10 min.

(3) PLA, PBAT and cardanol are added to the mixed solution in step (2), and magnetically stirred at 25° C. for 6 hours until all the raw materials are dissolved.

(4) Transfer the solution obtained in step (3) to a glass plate to make it evenly dispersed, and dry at 25° C. for 24 hours to solidify the film material.

(5) Carry out oxygen and moisture permeability tests on the obtained membrane materials, and the experimental data are shown in Table 3

Table 3 Oxygen permeability and moisture permeability test of the membrane materials prepared

Example 4

(1) Weigh 36g PLA and 4g PBAT, 0.4g Al ₂ O ₃ nanoparticles, and 1.6g cardanol.

(2) The Al ₂ O ₃ nanoparticles and cardanol in step (1) were added to 1000 ml of chloroform solution for ultrasonic dispersion for 6 min.

(3) PLA, PBAT and cardanol are added to the mixed solution in step (2), and magnetically stirred at 25° C. for 5 hours until all the raw materials are dissolved.

(4) Transfer the solution obtained in step (3) to a glass plate to make it evenly dispersed, and dry at 25° C. for 24 hours to solidify the film material.

(5) Carry out oxygen and moisture permeability tests on the obtained membrane material, and the experimental data are shown in Table 4.

Table 4 Oxygen permeability and moisture permeability test of the obtained membrane materials

Example 5

(1) Weigh 7.2 g PLA, 0.8 g PBAT, and 0.41 g cardanol.

(2) The cardanol in step (1) was added to 200 ml of chloroform solution for ultrasonic dispersion for 5 min.

(3) Add PLA, PBAT, and cardanol to the mixed solution in step (2), and stir magnetically at 25° C. for 5 h until all the raw materials are dissolved.

(4) Transfer the solution obtained in step (3) to a glass plate to make it evenly dispersed, and dry at 25°C for 24h to solidify the membrane material.

(5) Carry out oxygen and moisture permeability tests on the obtained membrane material, and the experimental data are shown in Table 5.

Table 5 Oxygen permeability and moisture permeability test of the film materials prepared

Example 6

(1) Weigh 7.2g PLA, 0.8g PBAT and 0.82g Al2O3 nanoparticles.

(2) ultrasonically dispersing the Al2O3 nanoparticles in step (1) in 200ml of chloroform solution for 5min.

(3) PLA and PBAT are added to the mixed solution in step (2), and magnetically stirred at 25° C. for 5 hours until all the raw materials are dissolved.

(4) Transfer the solution obtained in step (3) to a glass plate to make it evenly dispersed, and dry at 25°C for 24h to solidify the membrane material.

(5) Carry out oxygen and moisture permeability tests on the obtained membrane material, and the experimental data are shown in Table 6.

Table 6 Oxygen permeability and moisture permeability test of the obtained membrane materials

The experimental results of the above Example 2 and Example 5 show that the permeability of the membrane material prepared from the polylactic acid material with Al ₂ O ₃ nanoparticles and the polylactic acid material without the addition of Al ₂ O ₃ nanoparticles. Both oxygen and moisture permeability tests have been greatly improved.

The experimental results of the above-mentioned Example 2 and Example 6 show that the oxygen permeability and moisture permeability test of the film material obtained from the polylactic acid material added with cardanol and the film material obtained from the polylactic acid material without cardanol were all tested. raised.

At the same time, the tensile strength and tear strength of the film materials prepared in Examples 1-6 were tested, and the experimental data are shown in Table 7.

Table 7 is the tensile effect test of Examples 1-6

name Tensile strength (MPa) Tear Strength(KN/m) Example 1 10.32 41.28 Example 2 10.58 40.05 Example 3 11.74 42.11 Example 4 13.21 40.59 Example 5 9.28 38.08 Example 6 6.34 28.26

From the experimental data of Example 2 and the experimental data of Example 5 in Table 7, it is shown that the membrane material is prepared from the polylactic acid material with Al ₂ O ₃ nanoparticles and the membrane is prepared from the polylactic acid material without Al ₂ O ₃ nanoparticles. The tensile strength and tear strength of the material are both improved.

The experimental data of Example 2 and the experimental data of Example 6 in Table 7 show that the tensile strength and tear of the film material obtained from the polylactic acid material with cardanol and the polylactic acid material without cardanol are added. The strength is greatly increased.

It can be seen from the above experiments that:

1. The bio-based degradable polylactic acid material with high flexibility and high antibacterial properties prepared by the present invention improves the mechanical strength and heat resistance of the PLA and PBAT composite film by adding cardanol as a plasticizer, and increases the tensile strength of the material. , the heat resistance is improved.

2. The present invention can effectively improve the water vapor transmission rate and the contact angle with water of the composite membrane by adding Al ₂ O ₃ nanoparticles as a reinforcing agent, and at the same time, the contaminating bacteria of the material appear in the highest inhibition zone.

Claims (10)

1. A high-flexibility and high-antibacterial-property biodegradable polylactic acid material is characterized in that: the preparation raw materials of the high-flexibility and high-antibacterial-property bio-based degradable polylactic acid material comprise polylactic acid (PLA), polyethylene glycol adipate (PBAT), cardanol oil and aluminum oxide (Al) ₂ O ₃ ) Nano-particle composition, chloroform as solvent;

the mass ratio of the PLA to the PBAT is 9 (0.5-1); the mass ratio of PLA to chloroform is 1: (40-4); the cardanol oil content is 5-6% of the mass of PLA and PBAT, and Al ₂ O ₃ The content of the nano particles is 1 to 1.5 percent of the mass of PLA and PBAT.

2. The highly flexible and highly antibacterial bio-based degradable polylactic acid material according to claim 1, wherein: the average molecular weight of the PLA is 205000-207000g/mol.

3. The high-flexibility high-antibacterial-property biodegradable polylactic acid material according to claim 1, wherein: the PBAT has an average molecular weight of 141500-142000g/mol.

4. The highly flexible and highly antibacterial bio-based degradable polylactic acid material according to claim 1, wherein: the Al is ₂ O ₃ The particle diameter of the particles is 30-40nm.

5. The high-flexibility high-antibacterial-property biodegradable polylactic acid material according to claim 1, wherein: the density of the cardanol is 0.97-0.98g/cm < 3 >.

6. The high-flexibility high-antibacterial-property biodegradable polylactic acid material according to claim 1, wherein: the chloroform is PLA, PBAT, cardanol oil, al ₂ O ₃ A film forming solvent for the nanoparticles.

7. The preparation method of the high-flexibility and high-antibacterial-property biodegradable polylactic acid material according to the claims 1-6, wherein the preparation method comprises the steps of weighing the components according to the proportion, and mixing Al ₂ O ₃ And (3) placing the nano particles and cardanol in a chloroform solution for ultrasonic dispersion, adding PLA and PBAT according to mass, stirring and mixing uniformly, transferring the mixture to a glass culture dish for uniform distribution, and drying and curing at room temperature.

8. The method for preparing the high-flexibility and high-antibacterial-property biodegradable polylactic acid material according to claim 7, wherein the method comprises the following steps: the ultrasonic dispersion time is 5-10min.

9. The method for preparing the high-flexibility and high-antibacterial-property biodegradable polylactic acid material according to claim 8, wherein the method comprises the following steps: the stirring and mixing time is 3-4h, and the temperature is 23-25 ℃.

10. The method for preparing the high-flexibility and high-antibacterial-property biodegradable polylactic acid material according to claim 9, wherein the method comprises the following steps: the drying and curing time is 24-28h.