Dynamics affected memory for crystallization behaviors of poly (d-lactic acid)

Autor: Jizhong Chen, Huiying Wen, Shaoyong Huang, Hongfei Li, Tongxin Lv, Jingqing Li, Shichun Jiang
Rok vydání: 2020
Předmět:
Zdroj: Polymer. 211:123078
ISSN: 0032-3861
DOI: 10.1016/j.polymer.2020.123078
Popis: Dynamics of polymer chains not only is a fundamental bridge between the structures and properties of polymers but also plays a crucial role in the formation of polymer structures. The slow crystallization caused low crystallinity of Poly (lactic acid) (PLA) is the bottleneck for its applications. The chain dynamics affected memory for recrystallization morphology and behavior of poly ( d -lactic acid) (PDLA) were observed by POM and characterized by DSC. The POM images showed that the PDLA could outline the morphology of original banded spherulites after recrystallization from melting of the original spherulites. The re-formed crystal inherited the crystalline location from the original crystalline morphology, forming a circle ring morphology that is following up the initial banded spherulites, even though the circle ring was constructed of smaller spherulites. DSC results showed various crystallization behaviors of PLA recrystallization with different thermal history. The influence of heating temperature, keeping time, and cooling rate on the recrystallization morphology were investigated and discussed. It was proposed that the adjustment and change of PDLA chain conformation is more difficult in various states between the crystalline and melt than that of other polymers, which relates to the strength of melt and entropy.
Databáze: OpenAIRE