聚乳酸共混体系的拉伸性能、微观结构及结晶行为  

Study on tensile properties,microstructure and crystallization behavior of polylactide blends

作　　者：刘阳[1] 史学涛[1] 张广成[1] 李楠[1] 高文[1] 

机构地区：[1]西北工业大学理学院应用化学系,西安710129

出　　处：《功能材料》2014年第19期19010-19014,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51303149)

摘　　要：研究了不同含量的丁二醇-己二酸-对苯二甲酸共聚酯(PBAT)与聚丁二酸丁二醇酯(PBS)增韧聚乳酸(PLA)的二元共混体系以及添加LAK粒子(硫酸盐)的三元共混体系拉伸性能、微观结构以及结晶行为,并利用Avrami方程对结晶过程进行了模拟。结果表明,PBAT与PBS的添加都不同程度地改善了PLA的断裂伸长率,在拉伸强度下降较小的前提下大幅度提高了其韧性;LAK粒子能进一步提高PLA-10%PBS二元体系的断裂伸长率;拉伸破坏试样断面的SEM照片表明,两种聚合物界面处以及PLA和粒子之间在外力作用下形成的空洞化是共混体系韧性提高的主要原因;PBAT与PBS的添加均促进了PLA的结晶,PBS还引起了PLA晶型的转变;LAK粒子能够起到成核剂的作用,进一步缩短了两种增韧剂体系的半结晶时间;添加LAK粒子的增韧体系的Avrami方程拟合曲线平行,其成核方式及生长过程相似。The tensile properties,micro-structure and crystallization behavior of polylactide binary composites with butylene glycol - adipic acid - ternary terephthalate polyester (PBAT)or polybutylene succinate (PBS)and their ternary composites with further addition of rigid filler LAK (sulfate ingredient)were investigated in this work.The mechanical study indicated that the addition of PBAT or PBS resulted in great improvement of the elongation at break and enhanced the poor toughness of PLA.The addition of LAK particles into 10wt% PLA-PBS system also resulted in the improvement of its elongation at break.The morphology study of PLA tensile fracture surface by SEM indicated the dominated deformation mechanism of toughened PLA blends was attribu-ted to the cavitation formation from the interface between PLA and the second polymer or the rigid particles. Both the addition of PBAT and PBS promoted the crystallization behavior of PLA,and the addition of PBS also resulted in the different type of PLA crystalline.LAK particles acted as nucleating agents in the PLA ternary composites and further decreased the half-crystallization time.Based on the parameters calculated by Avrami equation,the addition of LAK particles into both PLA-PBAT and PLA-PBS system have the similar crystal nu-cleating and growth process.

关 键 词：聚乳酸 共混 增韧 微观结构 结晶 

分 类 号：TQ311[化学工程—高聚物工业]