FRS-XRSA与SAXS研究硬弹性聚丙烯的结晶度、取向与超结构Ⅲ应变与回复

应用全倒易空间Ｘ 射线散射理论分析（ＦＲＳ ＸＲＳＡ）与ＳＡＸＳ研究了ＨＥＰＰ在应变（ε）与回复（Ｒ）过程中结晶、取向与超结构的变化．结果指出，ε可以诱发结晶，但当ε≥３０％后，结晶度（ＸＷＣ）趋于不变：ε可以导致晶粒破碎；ε与Ｒ对取向分布与平均取向基本上无影响，这符合片晶平行分离模型，而非叶簧弯曲模型；发现，在ε≤３０％时，层状片晶的分离为主要过程，而当ε＞３０％后，则分离的片晶会发生断层滑移；ε可以诱发微孔，类似地当ε＞２０％，微孔尺寸亦趋不变．从凝聚态结构阐明了ＨＥＰＰ在ε Ｒ过程中不同阶段的结构变化

STUDIES ON THE CRYSTALLINITY,ORIENTATION AND SUPERSTRUCTURE OF HARD ELASTIC POLYPROPYLENE BY FRS XRSA AND SAXS Ⅲ. THE STRETCHING AND RECOVERY

The work is to investigate the effect of the stretching and recovery processes on the microstructure,orientation texture and superstructure of hard elastic polypropylene (HEPP) fibers by FRS XRSA and SAXS.The results show that strain induced crystallization,but when ε ≥30%, X W C approaches a conatant,～90%;strain induced the fragmentation of crystallites;strain induced the lamellae separation in parallel,not induced leaf spring bending,i.e.as ε increases,the orientation distribution of crystallites does not change;when ε ≤30%,the lamellae separation is the main process,when ε >30%,the lamellae layers occur fracture and slip along the fiber axis,thus,before and after ε =30% the atrain mechaniem of the hard elaticity is different;strain induced microvoids in HEPP,but as ε ≥20%,the microvoids'size approaches a definite value.These results have successfully been used to interpret the relationships between the structure and properties of HEPP.