Modified degradable polylactic acid composition and preparation method thereof
By hyperbranching modification of polylactic acid and blending with crosslinked products and dibenzoyl peroxide, the problem of slow degradation and insufficient performance of polylactic acid in the home environment is solved, and the rapid degradation and performance improvement of polylactic acid is achieved.
Patent Information
- Application Number
- CN202411955781.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-06-03
AI Technical Summary
The existing polylactic acid has slow degradation and degradation speed in the home environment and has performance deficiencies, such as high brittleness and poor stability, which limits its wide application.
The mechanical properties, mechanical properties and plastic application capabilities of polylactic acid are improved by modifying polylactic acid using hyperbranched polymers and blending them with crosslinked products and dibenzoyl peroxide.
While achieving rapid degradation of polylactic acid under home conditions, it improves its mechanical properties and plastic application capabilities, and is suitable for the production of hardened plastic products, film products, etc.
Smart Images
Figure BDA0005217974060000081
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of degradable polylactic acid, and specifically to a modified degradable polylactic acid composition and a preparation method thereof. Background Art
[0002] With the continuous improvement of environmental awareness, the "white pollution" problem caused by traditional plastic products has become increasingly serious. Polylactic acid, also known as poly(lactic acid), is a polymer obtained by polymerizing lactic acid as the main raw material, and is a new type of degradable material. Polylactic acid has good thermal stability, good solubility resistance, and good performance in biocompatibility, transparency, etc., and is mainly used in the fields of clothing, packaging, construction, agriculture, medical devices, etc. The wide application of polylactic acid is due to its excellent degradable performance, and it will not cause environmental damage during the production and use process. However, pure polylactic acid degrades slowly in the household environment and has some performance deficiencies, such as high brittleness and poor stability, which limit its wide application. Therefore, it is of great significance to develop a polylactic acid composition that can be rapidly degraded under household conditions and has better performance. Summary of the Invention
[0003] (1) Technical Problems to be Solved
[0004] In view of the deficiencies of the prior art, the present invention provides a modified degradable polylactic acid composition and a preparation method thereof.
[0005] (2) Technical Solutions
[0006] A preparation method of a modified degradable polylactic acid composition includes the following steps:
[0007] S1. Keep lactic acid at 100 - 120 °C and a vacuum degree of 300 - 350 Pa for 1 - 3 h, add the catalyst stannous chloride, stir, pass nitrogen, keep the reaction at 130 - 150 °C and a vacuum degree of 100 - 130 Pa for 1 - 3 h, then stir and react at 170 - 190 °C and a vacuum degree of 30 - 50 Pa for 8 - 16 h. After the reaction ends, add acetone to stir and dissolve, add water to precipitate, filter, and dry to obtain polylactic acid;
[0008] S2. Heat polyacrylate to 120 - 140 °C, add benzoyl peroxide, maleic anhydride, acrylamide, and xylene, stir evenly, add the initiator potassium persulfate and the crosslinking agent glycerol, react for 2 - 5 h, wash and filter with deionized water by boiling, then soak in deionized water for 12 - 24 h, and filter and dry by suction to obtain a crosslinked product;
[0009] S3. Place diethylenetriamine in an ice-water bath, pass nitrogen, and slowly dropwise add ethyl acrylate, acrylamide, and methanol solution. After the addition is complete, react at room temperature for 2 - 6 h, distill off methanol under reduced pressure, raise the temperature to 120 - 150 °C, and continue to react for 2 - 6 h to obtain a hyperbranched polymer;
[0010] S4. Blend polylactic acid and the hyperbranched polymer at 150 - 180 °C with a stirring speed of 50 - 100 r / min for 5 - 10 min to obtain a polylactic acid mixture;
[0011] S5. Mix the polylactic acid mixture, crosslinked product, and benzoyl peroxide uniformly, and place them in a reduced-pressure environment at 80 - 100 °C to react for 15 - 30 h to obtain a polylactic acid composition.
[0012] Preferably, in step S1, the mass ratio of lactic acid, stannous chloride, and acetone is 1:0.01 - 0.05:3 - 6.
[0013] Preferably, in step S2, the mass ratio of polyacrylate, benzoyl peroxide, maleic anhydride, acrylamide, xylene, initiator potassium persulfate, and crosslinking agent glycerol is 1:0.01 - 0.03:0.3 - 0.6:0.5 - 0.8:0.05 - 0.1:0.02 - 0.05:0.05 - 0.1.
[0014] Preferably, in step S3, the mass ratio of diethylenetriamine, ethyl acrylate, acrylamide, and methanol solution is 1:0.8 - 1.2:0.4 - 0.8:1.5 - 2.
[0015] Preferably, in step S4, the mass ratio of polylactic acid to the hyperbranched polymer is 1:0.05 - 0.1.
[0016] Preferably, in step S5, the mass ratio of the polylactic acid mixture, crosslinked product, and benzoyl peroxide is 1:0.3 - 0.6:0.01 - 0.05.
[0017] Preferably, the polylactic acid composition is applied in plastic films, 3D printing, medical devices, electronic products, and plastic products.
[0018] (III) Beneficial technical effects
[0019] The process of the present invention uses hyperbranched polymers to modify polylactic acid, obtaining a polylactic acid material with better mechanical and mechanical properties. Then, the cross-linked product of polyacrylate is used to modify the polylactic acid mixture to improve the plastic application ability. It can be used to produce plastic products such as hardened plastic products and film products. At the same time, degradable materials are used in the production process, which not only improves the performance of polylactic acid but also has degradable properties. The production process is green and environmentally friendly and has broad application prospects. Detailed implementation mode
[0020] Example 1
[0021] S1. Keep 10 kg of lactic acid at 100 °C and a vacuum of 300 Pa for 1 h, add 0.1 kg of catalyst stannous chloride, stir, pass nitrogen, keep the reaction at 130 °C and a vacuum of 100 Pa for 1 h, then stir and react at 170 °C and a vacuum of 30 Pa for 8 h. After the reaction is completed, add 30 kg of acetone to stir and dissolve, add water for precipitation, filtration, and drying to obtain polylactic acid.
[0022] S2. Heat 10 kg of polyacrylate to 120 °C, add 0.1 kg of benzoyl peroxide, 3 kg of maleic anhydride, 5 kg of acrylamide, and 0.5 kg of xylene, stir evenly, add 0.2 kg of initiator potassium persulfate and 0.5 kg of cross-linking agent glycerol, react for 2 h, boil and wash with deionized water for filtration, then soak in deionized water for 12 h, and filter and dry to obtain the cross-linked product.
[0023] S3. Place 3 kg of diethylenetriamine in an ice-water bath, pass nitrogen, slowly dropwise add 2.4 kg of ethyl acrylate, 1.2 kg of acrylamide, and 4.5 kg of methanol solution. After the dropping is completed, react at room temperature for 2 h, distill off methanol under reduced pressure, heat up to 120 °C, and continue to react for 2 h to obtain the hyperbranched polymer.
[0024] S4. Blend 6 kg of polylactic acid and 0.3 kg of hyperbranched polymer at 150 °C, with a stirring speed of 50 r / min for 5 min to obtain a polylactic acid mixture.
[0025] S5. Mix 5 kg of the polylactic acid mixture, 1.5 kg of the cross-linked product, and 0.05 kg of dibenzoyl peroxide, stir evenly, and place it in a reduced-pressure environment at 80 °C for reaction for 15 h to obtain a polylactic acid composition.
[0026] Example 2
[0027] S1. Keep 10 kg of lactic acid at 120 °C and a vacuum of 350 Pa for 3 h. Add 0.5 kg of stannous chloride catalyst, stir, and introduce nitrogen. Keep the reaction at 150 °C and a vacuum of 130 Pa for 3 h, and then stir and react at 190 °C and a vacuum of 50 Pa for 16 h. After the reaction, add 60 kg of acetone to stir and dissolve, add water for precipitation, filtration, and drying to obtain polylactic acid.
[0028] S2. Heat 10 kg of polyacrylate to 140 °C, add 0.3 kg of benzoyl peroxide, 6 kg of maleic anhydride, 8 kg of acrylamide, and 1 kg of xylene, stir evenly, add 0.5 kg of potassium persulfate initiator and 1 kg of crosslinking agent glycerol, react for 5 h, wash and filter by boiling with deionized water, then soak in deionized water for 24 h, and filter and dry by suction to obtain the crosslinked product.
[0029] S3. Place 3 kg of diethylenetriamine in an ice-water bath, introduce nitrogen, slowly dropwise add 3.6 kg of ethyl acrylate, 2.4 kg of acrylamide, and 6 kg of methanol solution. After the addition is complete, react at room temperature for 6 h, distill off methanol under reduced pressure, heat to 150 °C, and continue to react for 6 h to obtain the hyperbranched polymer.
[0030] S4. Blend 6 kg of polylactic acid and 0.6 kg of hyperbranched polymer at 180 °C, with a stirring speed of 100 r / min for 10 min to obtain the polylactic acid mixture.
[0031] S5. Mix 5 kg of polylactic acid mixture, 3 kg of crosslinked product, and 0.25 kg of benzoyl peroxide, stir evenly, place in a reduced-pressure environment at 100 °C and react for 30 h to obtain the polylactic acid composition.
[0032] Example 3
[0033] S1. Keep 10 kg of lactic acid at 110 °C and a vacuum of 320 Pa for 2 h. Add 0.2 kg of stannous chloride catalyst, stir, and introduce nitrogen. Keep the reaction at 140 °C and a vacuum of 120 Pa for 2 h, and then stir and react at 180 °C and a vacuum of 40 Pa for 10 h. After the reaction, add 40 kg of acetone to stir and dissolve, add water for precipitation, filtration, and drying to obtain polylactic acid.
[0034] S2. Heat 10 kg of polyacrylate to 130 °C, add 0.15 kg of benzoyl peroxide, 5 kg of maleic anhydride, 5.5 kg of acrylamide, and 0.6 kg of xylene, stir evenly, add 0.3 kg of potassium persulfate initiator and 0.6 kg of crosslinking agent glycerol, react for 4 h, wash and filter by boiling with deionized water, then soak in deionized water for 15 h, and filter and dry by suction to obtain the crosslinked product.
[0035] S3. Place 3 kg of diethylenetriamine in an ice-water bath, purge with nitrogen, slowly add dropwise 3 kg of ethyl acrylate, 1.5 kg of acrylamide, and 5 kg of methanol solution. After the addition is complete, react at room temperature for 3 h, distill off methanol under reduced pressure, raise the temperature to 140 °C, and continue to react for 3 h to obtain a hyperbranched polymer.
[0036] S4. Blend 6 kg of polylactic acid and 0.5 kg of hyperbranched polymer at 160 °C with a stirring speed of 60 r / min for 10 min to obtain a polylactic acid mixture.
[0037] S5. Mix 5 kg of polylactic acid mixture, 2 kg of crosslinked product, and 0.1 kg of benzoyl peroxide, stir evenly, and place in a reduced-pressure environment at 100 °C to react for 20 h to obtain a polylactic acid composition.
[0038] Example 4
[0039] S1. Keep 10 kg of lactic acid at 100 °C and a vacuum of 300 Pa for 3 h, add 0.4 kg of catalyst stannous chloride, stir, purge with nitrogen, keep at 150 °C and a vacuum of 120 Pa for 1.5 h, then stir and react at 170 °C and a vacuum of 50 Pa for 12 h. After the reaction is completed, add 50 kg of acetone to stir and dissolve, add water to precipitate, filter, and dry to obtain polylactic acid.
[0040] S2. Heat 10 kg of polyacrylate to 120 °C, add 0.2 kg of benzoyl peroxide, 4.5 kg of maleic anhydride, 6.2 kg of acrylamide, and 0.9 kg of xylene, stir evenly, add 0.4 kg of initiator potassium persulfate and 0.7 kg of crosslinking agent glycerol, react for 4 h, boil and wash with deionized water and filter, then soak in deionized water for 18 h, and filter and dry to obtain a crosslinked product.
[0041] S3. Place 3 kg of diethylenetriamine in an ice-water bath, purge with nitrogen, slowly add dropwise 3.2 kg of ethyl acrylate, 1.8 kg of acrylamide, and 5.4 kg of methanol solution. After the addition is complete, react at room temperature for 4 h, distill off methanol under reduced pressure, raise the temperature to 120 °C, and continue to react for 5 h to obtain a hyperbranched polymer.
[0042] S4. Blend 6 kg of polylactic acid and 0.5 kg of hyperbranched polymer at 160 °C with a stirring speed of 100 r / min for 10 min to obtain a polylactic acid mixture.
[0043] S5. Mix 5 kg of polylactic acid mixture, 2.5 kg of crosslinked product, and 0.15 kg of benzoyl peroxide, stir evenly, and place in a reduced-pressure environment at 80 °C to react for 30 h to obtain a polylactic acid composition.
[0044] Example 5
[0045] S1. Keep 10 kg of lactic acid at 120 °C under a vacuum of 300 Pa for 3 h. Add 0.5 kg of stannous chloride catalyst, stir, and introduce nitrogen. Keep the reaction at 130 °C under a vacuum of 100 Pa for 1 h, and then stir and react at 190 °C under a vacuum of 30 Pa for 15 h. After the reaction is completed, add 60 kg of acetone to stir and dissolve, add water for precipitation, filtration, and drying to obtain polylactic acid.
[0046] S2. Heat 10 kg of polyacrylate to 120 °C, add 0.1 kg of benzoyl peroxide, 3 kg of maleic anhydride, 8 kg of acrylamide, and 1 kg of xylene, stir evenly, add 0.5 kg of potassium persulfate initiator and 0.8 kg of crosslinking agent glycerol, react for 2 h, boil and wash with deionized water and filter, then soak in deionized water for 24 h, and filter and dry to obtain the crosslinked product.
[0047] S3. Place 3 kg of diethylenetriamine in an ice-water bath, introduce nitrogen, slowly dropwise add 3.5 kg of ethyl acrylate, 2 kg of acrylamide, and 5.5 kg of methanol solution. After the addition is complete, react at room temperature for 4 h, distill off methanol under reduced pressure, heat to 150 °C, and continue to react for 3 h to obtain a hyperbranched polymer.
[0048] S4. Blend 6 kg of polylactic acid and 0.3 - 0.6 kg of hyperbranched polymer at 150 - 180 °C with a stirring speed of 50 - 100 r / min for 5 - 10 min to obtain a polylactic acid mixture.
[0049] S5. Mix 5 kg of polylactic acid mixture, 2 kg of crosslinked product, and 0.2 kg of dibenzoyl peroxide, stir evenly, place in a reduced-pressure environment at 100 °C and react for 30 h to obtain a polylactic acid composition.
[0050] Comparative Example 1
[0051] S1. Keep 10 kg of lactic acid at 100 °C under a vacuum of 300 Pa for 1 h. Add 0.1 kg of stannous chloride catalyst, stir, and introduce nitrogen. Keep the reaction at 130 °C under a vacuum of 100 Pa for 1 h, and then stir and react at 170 °C under a vacuum of 30 Pa for 8 h. After the reaction is completed, add 30 kg of acetone to stir and dissolve, add water for precipitation, filtration, and drying to obtain polylactic acid.
[0052] S2. Place 3 kg of diethylenetriamine in an ice-water bath, introduce nitrogen, slowly dropwise add 2.4 kg of ethyl acrylate, 1.2 kg of acrylamide, and 4.5 kg of methanol solution. After the addition is complete, react at room temperature for 2 h, distill off methanol under reduced pressure, heat to 120 °C, and continue to react for 2 h to obtain a hyperbranched polymer.
[0053] S3. Blend 6 kg of polylactic acid and 0.3 kg of hyperbranched polymer at 150 °C with a stirring speed of 50 r / min for 5 min to obtain a polylactic acid mixture.
[0054] S4. Mix 5 kg of the polylactic acid mixture and 0.05 kg of benzoyl peroxide, stir evenly, and place it in a reduced-pressure environment at 80 °C for reaction for 15 h to obtain a polylactic acid composition.
[0055] Comparative Example 2
[0056] S1. Keep 10 kg of lactic acid at 100 °C and a vacuum degree of 300 Pa for 1 h, add 0.1 kg of catalyst stannous chloride, stir, pass nitrogen, keep the temperature at 130 °C and a vacuum degree of 100 Pa for reaction for 1 - 3 h, then stir and react at 170 °C and a vacuum degree of 30 Pa for 8 h. After the reaction, add 30 kg of acetone to stir and dissolve, add water for precipitation, filtration, and drying to obtain polylactic acid.
[0057] S2. Heat 10 kg of polyacrylate to 120 °C, add 0.1 kg of benzoyl peroxide, 3 kg of maleic anhydride, 5 kg of acrylamide, and 0.5 - 1 kg of xylene, stir evenly, add 0.2 kg of initiator potassium persulfate and 0.5 kg of crosslinking agent glycerol, react for 2 h, boil and wash with deionized water for filtration, then soak in deionized water for 12 h, and filter and dry to obtain a crosslinked product.
[0058] S3. Mix 5 kg of polylactic acid, 1.5 kg of the crosslinked product, and 0.05 kg of benzoyl peroxide, stir evenly, and place it in a reduced-pressure environment at 80 °C for reaction for 15 h to obtain a polylactic acid composition.
[0059] Comparative Example 3
[0060] S1. Keep 10 kg of lactic acid at 100 °C and a vacuum degree of 300 Pa for 1 h, add 0.1 kg of catalyst stannous chloride, stir, pass nitrogen, keep the temperature at 130 °C and a vacuum degree of 100 Pa for reaction for 1 h, then stir and react at 170 °C and a vacuum degree of 30 Pa for 8 h. After the reaction, add 30 kg of acetone to stir and dissolve, add water for precipitation, filtration, and drying to obtain polylactic acid.
[0061] S2. Mix 5 kg of polylactic acid and 0.05 kg of benzoyl peroxide, stir evenly, and place it in a reduced-pressure environment at 80 °C for reaction for 15 h to obtain a polylactic acid composition.
[0062] Performance Test:
[0063] Determine the degradation rate of Examples 1 - 5 and Comparative Examples 1 - 3 under natural conditions. The determination method is as follows: According to the method of GB / T18006.2 - 1999, make the polylactic acid in the above examples and comparative examples into 16 cm2 Square plates with a thickness of 5 mm are dispersedly arranged in the measurement site. Observe daily and record the date when the mildew and deformation area on the surface of the sample reaches more than 50% of the total area of the sample, which is recorded as the mildew days, and record the date when the sample fragments, which is recorded as the fragmentation days.
[0064] Prepare samples for the above-mentioned examples and comparative examples according to the general test method in ISO-527-1-2012, and measure their tensile properties.
[0065] Table 1
[0066]
[0067]
[0068] As can be seen from Table 1, the polylactic acid polymers prepared in Examples 1 to 5 have good degradability and better tensile strength.
[0069] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a modified degradable polylactic acid composition, characterized in that: The following steps are involved: S1. Keep lactic acid at 100-120°C and vacuum degree of 300-350 Pa for 1-3 h, add stannous chloride as a catalyst, stir, pass nitrogen, keep the reaction at 130-150°C and vacuum degree of 100-130 Pa for 1-3 h, then stir and react at 170-190°C and vacuum degree of 30-50 Pa for 8-16 h, add acetone after the reaction is completed, stir and dissolve, add water to precipitate, filter and dry to obtain polylactic acid; S2, heating the polyacrylate to 120-140°C, adding benzoyl peroxide, maleic anhydride, acrylamide and xylene, stirring evenly, adding initiator potassium persulfate and cross-linking agent glycerol, reacting for 2-5 h, boiling, washing and filtering with deionized water, soaking with deionized water for 12-24 h, filtering and drying to obtain a cross-linked product; S3, placing diethylenetriamine in an ice water bath, passing nitrogen, slowly dropping ethyl acrylate, acrylamide and methanol solution, reacting at room temperature for 2-6 hours after the dropwise addition is complete, removing methanol by reduced pressure distillation, raising the temperature to 120-150°C, and continuing the reaction for 2-6 hours to obtain a hyperbranched polymer; S4, blending polylactic acid and hyperbranched polymer at 150-180° C., stirring at a speed of 50-100 r / min for 5-10 min to obtain a polylactic acid mixture; S5. Mix the polylactic acid mixture, the cross-linked product and dibenzoyl peroxide, stir evenly, and place in a reduced pressure environment at 80-100° C. to react for 15-30 h to obtain a polylactic acid composition.
2. The method for preparing a modified degradable polylactic acid composition according to claim 1, characterized in that: In step S1, the mass ratio of lactic acid, stannous chloride and acetone is 1:0.01-0.05:3-6.
3. The method for preparing a modified degradable polylactic acid composition according to claim 1, characterized in that: In step S2, the mass ratio of polyacrylate, benzoyl peroxide, maleic anhydride, acrylamide, xylene, initiator potassium persulfate, and crosslinking agent glycerol is 1:0.01~0.03:0.3~0.6:0.5~0.8:0.05~0.1:0.02~0.05:0.05~0.
1.
4. The method for preparing a modified degradable polylactic acid composition according to claim 1, characterized in that: In step S3, the mass ratio of diethylenetriamine, ethyl acrylate, acrylamide and methanol solution is 1:0.8-1.2:0.4-0.8:1.5-2.
5. The method for preparing a modified degradable polylactic acid composition according to claim 1, characterized in that: In the step S4, the mass ratio of polylactic acid to hyperbranched polymer is 1:0.05-0.
1.
6. The method for preparing a modified degradable polylactic acid composition according to claim 1, characterized in that: In the step S5, the mass ratio of the polylactic acid mixture, the cross-linked product, and dibenzoyl peroxide is 1:0.3-0.6:0.01-0.
05.
7. An application of a polylactic acid composition prepared by the preparation method according to any one of claims 1 to 6, characterized in that: The polylactic acid composition is used in plastic films, 3D printing, medical equipment, electronic products and plastic products.