立体复合晶体和柔性链段对聚（L-丙交酯）结晶及拉伸行为的影响

Effect of stereocomplex crystal and flexible segments on the crystallization and tensile behavior of poly(l-lactide).

作者信息

Li Xiaolu, Zhang Xiuqin, Liu Guoming, Yang Zhongkai, Yang Bo, Qi Yue, Wang Rui, Wang De-Yi

机构信息

Beijing Key Laboratory of Clothing Materials R & D and Assessment, Beijing Engineering Research Center of Textile Nanofiber, School of Materials Science & Engineering, Beijing Institute of Fashion Technology Beijing 100029 China

CAS Key Laboratory of Engineering Plastics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China.

出版信息

RSC Adv. 2018 Aug 9;8(50):28453-28460. doi: 10.1039/c8ra05355c. eCollection 2018 Aug 7.

DOI:10.1039/c8ra05355c

PMID:35542484

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9083944/

Abstract

The effects of poly(ethylene glycol) (PEG) and/or poly(d-lactide) (PDLA) blocks on the crystallization and mechanical properties of poly(l-lactide) (PLLA) were investigated systematically differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide-angle X-ray diffraction (WAXD) and tensile testing. The structural evolution during uniaxial stretching of the obtained blends above the glass transition temperature was studied by WAXD. It was observed that the stereocomplex (SC) crystals promoted the nucleation of PLLA homocrystals (α/α' crystal), and flexible PEG blocks could enhance the spherulitic growth rate. The PLLA/PDLA-PEG-PDLA had a higher elongation at break than that of PLLA/PDLA without significant loss in tensile strength and stiffness. WAXD showed that the PLLA/PDLA-PEG-PDLA crystallized faster during stretching. It was shown that the incorporation of SC crystals and flexible PEG blocks could not only accelerate the crystallization but also improve the toughness of PLLA.

摘要

通过差示扫描量热法（DSC）、偏光显微镜（POM）、广角X射线衍射（WAXD）和拉伸试验，系统研究了聚乙二醇（PEG）和/或聚（d-丙交酯）（PDLA）嵌段对聚（l-丙交酯）（PLLA）结晶和力学性能的影响。利用WAXD研究了在玻璃化转变温度以上获得的共混物单轴拉伸过程中的结构演变。观察到立构复合（SC）晶体促进了PLLA均相晶体（α/α'晶体）的成核，并且柔性PEG嵌段可以提高球晶生长速率。与不含PDLA的PLLA相比，PLLA/PDLA-PEG-PDLA具有更高的断裂伸长率，且拉伸强度和刚度没有显著损失。WAXD表明，PLLA/PDLA-PEG-PDLA在拉伸过程中结晶更快。结果表明，引入SC晶体和柔性PEG嵌段不仅可以加速结晶，还可以提高PLLA的韧性。