A kind of fully stereotactic high toughness polylactic acid stereocomplex and preparation method thereof

The technology of a stereocomplex and polylactic acid is applied in the field of fully stereotactic high-toughness polylactic acid stereocomplex and its preparation, which can solve the problems of low crystallization temperature, low crystallinity of stereocomplex, slow speed, etc. Simple preparation process, improved stereocomplex crystallinity and toughness, and good market prospects

Active Publication Date: 2021-08-17
云南利翀科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, stereocomplex polylactic acid is usually prepared by melting and blending L-polylactic acid and D-polylactic acid and then cooling and crystallizing. The stereocomplex crystallinity of the obtained product is low, and the crystallization temperature is low and the speed is slow, and the product is severely brittle

Method used

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  • A kind of fully stereotactic high toughness polylactic acid stereocomplex and preparation method thereof
  • A kind of fully stereotactic high toughness polylactic acid stereocomplex and preparation method thereof
  • A kind of fully stereotactic high toughness polylactic acid stereocomplex and preparation method thereof

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preparation example Construction

[0040] The present invention also provides a method for preparing a completely stereotactic high-toughness polylactic acid stereocomplex, comprising the following steps:

[0041] a) Melt blending 50 parts by weight of L-polylactic acid, 50 parts by weight of D-polylactic acid, 10-20 parts by weight of a compatible blend and 10-20 parts by weight of a toughening agent to obtain a blended melt;

[0042] The compatible blend comprises polyvinyl acetate and / or polyracemic lactic acid; the toughening agent comprises vinyl acetate-vinyl laurate copolymer and / or racemic lactic acid-caprolactone copolymer;

[0043] b) performing isothermal crystallization on the blended melt to obtain a completely stereoscopic high-toughness polylactic acid stereocomplex;

[0044] The temperature of the isothermal crystallization is 90-140°C.

[0045] In the preparation method provided by the present invention, firstly, the L-polylactic acid, the D-polylactic acid, the compatible blend and the toughe...

Embodiment 1

[0054] 50 parts by weight of L-polylactic acid (99% optical purity) with a weight average molecular weight of 300,000, 50 parts by weight of D-polylactic acid (99% optical purity) with a weight average molecular weight of 100,000, and poly 10 parts by weight of vinyl acetate, 20 parts by weight of a vinyl acetate-vinyl laurate copolymer (the molar content of the polymer repeating unit corresponding to vinyl laurate in the copolymer is 8%) with a weight average molecular weight of 30,000, Vacuum dry at 80°C until the moisture content is lower than 200ppm; put the mixed materials into the internal mixer, melt and blend at 240°C for 10 minutes, and then make a sheet with a thickness of 1mm on a flat vulcanizer at 240°C and 10MPa. Isothermal crystallization at 90° C. for 60 minutes to obtain a completely stereoscopic high-toughness polylactic acid stereocomplex sheet.

[0055] Carry out performance evaluation to gained sheet material, specific evaluation index is as follows:

[0...

Embodiment 2

[0064] 50 parts by weight of L-polylactic acid (96% optical purity) whose weight average molecular weight is 100,000, 50 parts by weight of D-polylactic acid (98% optical purity) whose weight average molecular weight is 200,000, poly 20 parts by weight of racemic lactic acid, 10 parts by weight of racemic lactic acid-caprolactone copolymer (the molar content of the polymer repeating unit corresponding to caprolactone in the copolymer is 20%) with a weight average molecular weight of 200,000, Vacuum dry at 80°C until the moisture content is lower than 200ppm; put the mixed material into the internal mixer, melt and blend at 220°C for 5 minutes, and then make a sheet with a thickness of 4mm on a flat vulcanizer at 220°C and 10MPa, The isothermal crystallization was carried out at ℃ for 3 minutes to obtain a completely stereoscopic high-toughness polylactic acid stereocomplex sheet.

[0065] The evaluation method of Example 1 is used to evaluate the performance of the obtained sh...

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Abstract

The invention belongs to the field of polymer composite materials, and in particular relates to a completely stereotactic high-toughness polylactic acid stereocomplex and a preparation method thereof. The polylactic acid stereocomplex provided by the present invention is prepared by isothermal crystallization after melt blending of raw materials; the raw materials include: 50 parts by weight of L-polylactic acid; 50 parts by weight of D-polylactic acid; compatible blend 10 ~20 parts by weight; 10~20 parts by weight of toughening agent; said compatible blend includes polyvinyl acetate and / or polyracemic lactic acid; said toughening agent includes vinyl acetate-vinyl laurate copolymer And / or racemic lactic acid-caprolactone copolymer; the temperature of the isothermal crystallization is 90-140°C. The present invention strictly controls the dosage ratio of L-polylactic acid and D-polylactic acid in raw materials, and adds compatible blends and toughening agents, and adopts an isothermal crystallization process, so that the polylactic acid stereocomplex provided Stereocomplex crystallinity and toughness have been significantly improved.

Description

technical field [0001] The invention belongs to the field of polymer composite materials, and in particular relates to a completely stereotactic high-toughness polylactic acid stereocomplex and a preparation method thereof. Background technique [0002] Polylactic acid is a polymer material that is chemically synthesized after fermenting lactic acid from plant resources. After being discarded, it can be completely decomposed into water, carbon dioxide and organic matter under the action of microorganisms, etc., without polluting the environment. It is a typical plant source. biodegradable plastic. Since polylactic acid has the advantages of complete plant origin, complete biodegradability, biocompatibility, bioabsorbability and easy processing, it is an ideal substitute for petroleum-based polymer materials, whether it is in the field of biomedical materials, Or in the field of general-purpose plastics, they all show broad application prospects, which can effectively solve ...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C08L67/04C08L31/04C08J5/18B29B7/00
CPCB29B7/002C08J5/18C08J2367/04C08J2431/04C08J2467/04C08L67/04C08L2205/025C08L2205/03C08L2205/035C08L2205/06C08L2205/08C08L31/04
Inventor于彦存边俊甲韩常玉董丽松
Owner云南利翀科技有限公司