聚乳酸立构三嵌段共聚物的结晶和相分离竞争机制研究

项目名称： 聚乳酸立构三嵌段共聚物的结晶和相分离竞争机制研究

项目编号： No.21506167

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 罗春燕

作者单位： 西安工业大学

项目金额： 21万元

中文摘要： 聚乳酸(PLA)以其良好的生物相容性和生物可降解性受到广泛关注。PLA有左旋聚乳酸(PLLA)(结晶性)、右旋聚乳酸(PDLA)(结晶性)和消旋聚乳酸(PDLLA)(非晶)三种立构体。三者因有相同的化学组成而热力学相容性好，却有不同的结晶性。首先，本申请拟定量考察以PLLA、PDLA、PDLLA为端嵌段的PLA-PEG-PLA共聚物中相分离、结晶及结晶动力学。第二，本项目拟将三种立构体设计合成为聚乳酸三嵌段立构共聚物，既整链具有相同的化学组成，但各嵌段具有不同结晶能力，考察立构共聚物的分相、结晶行为及结晶动力学。第三，立构体组成的共聚物各嵌段相容性较好，为弱相互作用系统，本申请拟利用MC方法模拟弱相互作用系统的分相及构象分布情况，对完善微相分离和结晶之间的竞争机制提供帮助。聚乳酸立构共聚物区别于传统上不同化学成分组成的共聚物，将进一步完善聚乳酸共聚改性机理和共聚物相分离及结晶竞争机制。

中文关键词： 嵌段共聚物；聚乳酸；相分离；结晶动力学；模拟

英文摘要： Poly(lactide) (PLA) has been widely concernned due to the biocompatibility and biodegradability. There are there enantiomeric poly(lactides): poly(D-lactide) (crystallizable), poly(L-lactide) (slow crystallizable) and poly(D,L-lactide) (amorphous), which have good miscibility due to the same composition but different crystallization behavior. Firstly, the phase separation, crystallization behavior and crystallization dynamics in PLA-PEG-PLA triblock copolymers with PLLA, PDLA and PDLLA as end blocks will be investigated, respectively. Secondly, the triblock copolymers composed of the three enantiomeric poly(lactides), which have a homogeneous chemical composition but different crystallinities for each blocks, will be designed and synthesized in this work. The phase separation, crystallization behavior and crystallization dynamics will be investigated. Thirdly, there is a good miscibility and a weak interaction between blocks in enantiomeric poly(lactides) triblock copolymers. The monte carlo (MC) simulation method will be used to investigate the phase separation behavior and the chain conformation in triblock copolymer with weak interaction between blocks, which will be helpful to the improvement of competition mechanism between phase separation and crystallization. This study is different from the traditional investigation on phase separation and crystallization behavior of the coplymer composed by different chemical components, which will be helpful to the further understand of the copolymerization modification of PLA and the competition mechanism between crystallization and phase separation behavior.

英文关键词： block copolymer;Poly(lactide) ;phase separation;Crystallization dynamics;simulation