文献类型：期刊文献

中文题名：立构二嵌段聚乳酸微纳米纤维的制备与结晶性能

英文题名：Preparation and Crystallization Properties of di-Stereoblock Polylactides Micro/Nanofibers

作者：钟郭程[1];陈涛[1,3];赵黎明[2,3];邱勇俊[2,3];徐梦帆[1]

机构：[1]华东理工大学材料科学与工程学院,上海市先进聚合物材料重点实验室,上海200237;[2]华东理工大学生物工程学院,上海200237;[3]华东理工大学中国轻工业生物基材料工程重点实验室,上海200237

年份：2020

卷号：46

期号：4

起止页码：480

中文期刊名：华东理工大学学报（自然科学版）

外文期刊名：Journal of East China University of Science and Technology

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD_E2019_2020】；

基金：国家重点研发计划项目(2017YFB0309301,2017YFB0309302);上海市自然科学基金(17ZR1407200)。

语种：中文

中文关键词：聚乳酸;立构嵌段;立构复合;静电纺丝

外文关键词：polylactide;stereoblock;stereocomplex;electrospinning

摘要：以羟基封端D型聚乳酸(HO-PDLA)作为大分子引发剂引发L-丙交酯(L-LA)本体开环聚合制备了不同数均分子量的线性立构二嵌段聚乳酸(di-sb-PLA),并应用静电纺丝技术制备了亚微米级纤维。结果表明:所合成的di-sb-PLA形成了完全的立构复合(sc)晶型,熔点均超过了215℃,热稳定性得到改善并表现出良好的韧性,浇注膜的断裂伸长率可达250%。电纺纤维膜中聚乳酸(PLA)分子链呈高度无定形状态,通过冷结晶生成大量的sc晶体,比熔融淬火样有更强的结晶能力。sc晶体的生成与甲基和羰基的相互作用有关。
By controlling the molar ratio of D-enantiomer to L-enantiomer of the lactide,a series of di-stereoblock polylactides(di-sb-PLA)bearing similar block sequences between poly(D-lactide)(PDLA)and poly(L-lactide)(PLLA)were synthesized by ring-opening polymerization of L-lactide(L-LA)using hydroxyl terminated PDLA(HO-PDLA)as a macromolecular initiator.Micro/nanofibers were then fabricated by electrospinning di-sb-PLAs from their dichloromethane(DCM)and hexafluoroisopropanol(HFIP)mixtures.The thermal and mechanical properties,fiber morphology and crystallization properties of di-sb-PLAs were analyzed.The results of DSC showed that di-sb-PLA formed complete stereocomplex(sc)crystals with the melting point higher than 215℃,and no homocrystal was formed.The crystallization ability of sc was decreased with an increase in length of each block.It is worth to note that sc of stereoblock PLA was formed on molecular-scale without post-processing compared with PLA homopolymers,which enhanced the heat resistance and improved the elongation at break of solution-cast film to 250%without losing tensile strength,especially for di-sb-PLAs that has higher molecular weight.After electrospinning,the as-spun micro/nanofibers of di-sb-PLA were homogeneous and smooth,in which PLA molecules were almost amorphous.A large amount of sc crystals were then formed by cold crystallization during heating-up process,and the melting points of sc crystals in these fibers were increased by 8℃ as compared with the melt-quenched samples.Moreover,the results of in-situ ATR-FT-IR at variable temperature disclosed that the formation of sc crystals was related to the interactions between side methyl groups and carbonyl groups in PLA.The results hold promise for the further application of di-sb-PLA.