P(GA-co-LA)纤维由于具有优异的拉伸强度和合适的体内降解速率而作为手术缝合线被大量应用，我国目前正在开发的P(GA-co-LA)纤维在关键性能上与国外产品仍有不小差距，主要原因是外场条件下可共晶链结构对结晶行为的影响规律及其精确调控这个关键科学问题未深入研究。本项目采用不同LA含量的P(GA-co-LA)共聚酯，通过调节制备工艺条件来调控P(GA-co-LA)纤维加工过程中的共晶结构，主要利用同步辐射WAXD/SAXS联用测试平台，离线及在线深入系统研究P(GA-co-LA)纤维在热拉伸和热定型过程中聚集态结构特别是共晶的形成和演化、以及这种结构演化与最终纤维的力学性能和降解性能之间的关系，揭示外场作用下共晶的形成与演化的内在机理，实现链结构和工艺条件对可共晶的P(GA-co-LA)聚集态结构形成和演化的调控，为提升P(GA-co-LA)纤维的性能奠定理论和工艺基础。

P (GA-co-LA) fibers are widely used as sutures due to their excellent tensile strength and suitable degradation rate in vivo. At present, the P (GA-co-LA) fiber developed in China still has a large gap with foreign products in the key properties. The main reason is that the influence of isomorphous chain structure on the crystallization behavior and its precise modulation have not been thoroughly studied. This project, based on the modulation of isomorphous structure of P(GA-co-LA) fibers during processing by adjusting the preparation process conditions, using P(GA-co-LA) copolyesters with different LA contents and WAXD/SAXS technology in Synchrotron Radiation Facility, offline and online in-depth researches the formation and evolution of the aggregation structure, especially the isomorphous structure, of P(GA-co-LA) fiber during hot-stretching and thermal setting, and the relationship between the structural evolution and the mechanical properties and degradation properties of the fibers. The aim of this project is to reveal the intrinsic mechanism of the formation and evolution of polymer isomorphous crystals under the external field, and modulate the formation and evolution of isomorphous P(GA-co-LA) aggregates by chain structure and process conditions. This project can provide the theoretical and technological foundation for improving the properties of P (GA-co-LA) fibers.