Stereo regularity in polymer materials is known that can gives significant effect on the development of semi crystalline structure via a strain induced crystallization. The content of D-isomer plays an important role in the stereo regularity of Poly(Lactic) Acid polymer. This study is about the effect of D-isomer contents of 2%, 4% and 12% under uniaxial drawing with the speed of 6 s_-1 at temperature ${80}^{\circ }\text{C}$ on the crystallization behaviour of Poly(Lactic) Acid. The evolution of PLA samples crystallization were studied based on WAXD patterns data recorded within time resolved stretching experiment at synchrotron radiation. This study found that the crystallization began after drawing has ceased completely for all samples regardless the content of D-isomer. The uniaxial drawing only gives affects on the increment of polymer molecular orientation prior to the onset of crystallization. The crystallization occured after deformation and it was influenced by the polymer molecular orientation, where, the crystallization rates and degree of crystallinity is low when D-isomer content is high. PLA random copolymer with 12% D-isomer have crystallized at draw ratio 6.0, while compared with the PLA random copolymer containing 2% and 4% D-isomer have crystallized at draw ratio around 3.0. The rate of crystallization for 12% D-isomer was just 0.28 s_-1 when compared with around 4.0 s_-1 for PLA samples with 2% and 4% D-isomer contents respectively. The PLA random co-polymer studied in this work have been crystallized into α’ crystal structure with some degrees of crystallinity. The degree of crystallinity is inversely correlated and the size of crystallite is directly correlated with the D-isomer content.

已知聚合物材料中的立体规则性可以通过应变诱导结晶对半结晶结构的发展产生显着影响。D-异构体的含量在聚乳酸聚合物的立构规整度中起重要作用。这项研究是关于在温度下以6 s _-1的速度单轴拉伸下D-异构体含量分别为2％，4％和12％的影响${80}^{\circ }\text{C}$聚乳酸的结晶行为 根据WAXD模式数据记录了PLA样品结晶的演变，该数据在同步加速器辐射的时间分辨拉伸实验中记录。这项研究发现，对于所有样品，无论D-异构体的含量如何，结晶都在拉制后完全停止。单轴拉伸仅影响结晶开始之前聚合物分子取向的增加。结晶在变形后发生，并且受聚合物分子取向的影响，其中，当D-异构体含量高时，结晶速率和结晶度低。具有12％D-异构体的PLA无规共聚物以6.0的拉伸比结晶，与含有2％和4％D-异构体的PLA无规共聚物相比，其拉伸比约为3.0。12％D-异构体的结晶速率仅为0.28 s_-1时，D-异构体含量分别为2％和4％的PLA样品的时长约为4.0 s _-1。在这项工作中研究的PLA无规共聚物已经结晶成具有一定结晶度的α'晶体结构。结晶度成反比，微晶尺寸与D-异构体含量成正比。