PGLA纤维拉伸过程中结晶与取向的变化

Crystallinity and orientation of PGLA fiber during drawing

为更好地控制乙交酯-l-丙交酯共聚(PGLA)纤维力学性能和降解特征,研究PGLA纤维拉伸过程中结晶与取向的变化。结果表明:随拉伸条件的变化,PGLA纤维结晶度呈现出明显的分段线性变化规律;应变诱导结晶主导了纤维拉伸中的结晶形成;在实验条件下,结晶过程存在不同的动力学阶段。根据非晶区取向函数对结晶度呈现的正相关性,同时结合DSC升温扫描的冷结晶峰随拉伸条件变化的结果,认为PGLA纤维拉伸过程中的结晶机制为应变诱导结晶。

For better control of mechanical properties and degradation characteristics of poly（glycolide-co-l-lactide） （PGLA） fiber,the influences of drawing on the crystallinity and orientation of PGLA fiber were studied. It was found that as the drawing condition changes, the crystallinity of PGLA fiber presents a section-based linear transformation rule markedly. The strain-induced crystallization dominates the crystal formation during fiber drawing. Under the experimental conditions, kinetics varies with stages during crystallization process. Owing to the fact that there is positive correlation between the amorphous orientation function and the crystallinity and considering the peaks of cold crystallization vary with drawing conditions, as shown by DSC, it is suggested that the crystallization mechanism of PGLA fiber during drawing is strain-induced crystallization.