生物基聚(乳酸-蓖麻油酸)的合成与立构复合及改性聚乳酸

项目名称： 生物基聚(乳酸-蓖麻油酸)的合成与立构复合及改性聚乳酸

项目编号： No.51473166

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 黄绍永

作者单位： 中国科学院长春应用化学研究所

项目金额： 95万元

中文摘要： 聚乳酸是具有良好应用前景的生物基可降解型高分子材料，但其结晶速度慢，耐热温度不高，韧性和抗冲击强度差的缺点限制了其广泛应用。文献报道，植物油脂基聚合物具有良好的柔韧性，能有效改善聚乳酸的韧性和抗冲击性能。同时，聚乳酸立构复合体可以改善其结晶行为，提高耐热温度和力学强度。但植物油脂基聚合物与聚乳酸相容性差，而其嵌段共聚物可以消除宏观相分离，且具有丰富的微结构。本项目的重点在于设计合成不同分子形态结构的生物质聚(L-乳酸-蓖麻油酸)(PLLA-b-PRA)和聚(D-乳酸-蓖麻油酸)(PDLA-b-PRA)嵌段共聚物，并研究其分子量及其分布、链段比例、熔融历史、结晶路线、剪切作用等因素对PLLA-b-PRA/PDLA-b-PRA体系结晶规律和结构的影响，通过对共混体系结晶行为和结构的调控，制备结构可控的立构复合物和壳-核复合结构，探索其在改性聚乳酸中的应用，开发高性能化聚乳酸材料。

中文关键词： 生物基高分子；聚乳酸；环境友好；纳米复合材料；生物降解材料

英文摘要： Polylactide (PLA) is a biodegradable and bio-based polymer, which has been used as biomedical and environment-friendly materials.Broader implementation of the materials is limited due to its inherent deficiencies, such as slow growth rate, low heat-resistant temperature, brittleness and bad shock resistance. It is reported that the vegrtable oil-based polymers can be used as modifiers for PLA resion, such as the rubbery poly(ricinolei acid) (PRA),of which its molecular weight of 10 000 g/mol has excellent toughness.PLLA stereocomplex can enhance crystallizaiton, heat-resistant temperature and mechanical strength of PLA.Tough PRA and PLA are strong segregated, more abundant microscopic structures and morphologies can be obtained in crystalline-rubbery PLA-PRA block copolymers without macroscopic separaiton. In the work, PLLA-b-PRA and PDLA-b-PRA with different molecular weight and componment ratio will be synthesized, and the influences of molecular weight, PRA/PLLA (PDLA) ratio, crystallization pathway, shear effect on crystallization and strucure of PLLA-b-PRA/PDLA-b-PRA blend,and heat-resistance and mechanical properties. The crystallization and structure of PLLA-b-PRA/PDLA-b-PRA blends, the relationship between the final strcture, internal factors of the blends, and the external factors including crystallization conditions,will be further infestigated, which are all of importance for the performance of PLA materials. The stereocomplex of PLLA/PDLA can be used as nucleating agent for PLLA homopolymer, of which the nucleation, the crystallization growth rate and crystalline strucutre will be enhanced. The heat-resistance temperature and strength of PLLA material can also be enhanced due to the foramtion of PLLA/PDLA stereocomplex. Furthermore, core-shell structures of Rubbery PRA and PLLA/PDLA stereocomplex can be obtained by self-assemble of the block copolymers and stereocomplex crystallization of PLLA/PDLA, and these microscale and nanoscale structures will enhance the toughness and strength of PLLA.The interfical interaction between PLLA and the rubbery PRA is increased by the addition of PLLA-b-PRA and PDLA-b-PRA block copolymers. Meanwhile, the long PLLA and PDLA chains and the microscale crystals of PLLA/PDLA stereocomplex enhance PLLA chain entanglements, which is favor for the enhancement of PLLA melt strength. The processing of PLLA melt can be improved by increasing the melt strength. Furthermore, core-shell structures of Rubbery PRA and PLLA/PDLA stereocomplex can be obtained by self-assemble of the block copolymers and stereocomplex crystallization of PLLA/PDLA, and these microscale and nanoscale structures will enhance the toughness and strength of PLLA.

英文关键词： bio-based polymers;polylactide;environment-friendly;nanocomposite;biodegradable materials