Role of Stretching-induced Crystallization on Mesoscale Morphology Transition of UHMWPE during Hot Stretching  

作　　者：Kai Huang Jia-Jia Mo Wen-Jing Shi Shi-Tong Wang Hong-Hui Shi Chun-Guang Shao Chun-Tai Liu Bao-Bao Chang 

机构地区：[1]National Engineering Research Center for Advanced Polymer Processing Technology,Zhengzhou University,Zhengzhou,450002,China

出　　处：《Chinese Journal of Polymer Science》2025年第1期188-198,I0013,共12页高分子科学(英文版)

基　　金：supported by the National Natural Science Foundation of China(Nos.52003249,12072325 and 52273027);the Natural Science Foundation of Henan(No.242300421236).

摘　　要：In this work,a morphology transition mode is revealed in ultra-high molecular weight polyethylene(UHMWPE)when stretching at 120℃:moving from the slightly deformed region to the necked region,the morphology transfers from small spherulites to a mixture of transcrystalline and enlarged spherulites,and finally to pure transcrystalline;meanwhile,the lamellae making up the transcrystalline or spherulite were fragmented into smaller ones;spatial scan by wide-angle X-ray scattering(WAXS)and small angle X-ray scattering(SAXS)revealed that the crystallinity is increased from 25.3%to 30.1%and the crystal orientation was enhanced greatly,but the lamellae orientation was quite weak.The rise of enlarged spherulites or a mixture of transcrystalline and spherulites can also be found in UHMWPE stretched at 140 and 148℃,whereas absent in UHMWPE stretched at 30℃.In situ WAXS/SAXS measurements suggest that during stretching at 30℃,the crystallinity is reduced drastically,and a few voids are formed as the size increases from 50 nm to 210 nm;during stretching at 120℃,the crystallinity is reduced only slightly,and the kinking of lamellae occurs at large Hencky strain;during stretching at 140 and 148℃,an increase in crystallinity with stretching strain can be found,and the lamellae are also kinked.Taking the microstructure and morphology transition into consideration,a mesoscale morphology transition mode is proposed,in the stretching-induced crystallization the fragmented lamellae can be rearranged into new supra-structures such as spherulite or transcrystalline during hot stretching.

关 键 词：UHMWPE Stretching induced crystallization Lamellae fragmentation Mesoscale structural transition 

分 类 号：TQ3[化学工程]