制样方法对超拉伸聚乙烯纤维DSC熔融行为的影响

The effect of methods of preparing samples on DSC melting bahavior of UHMW-PE fibers

用切断、揉球、定长三种制样方式测定不同拉伸倍率的ＵＨＭＷ－ＰＥ纤维的ＤＳＣ曲线存在着很大差别，切断使纤维处于完全松驰状态，ＤＳＣ曲线上只出现表征正交晶系串晶的熔融峰和六方晶系结晶熔融的小峰，定长方式抑制了纤维的收缩，使串晶的熔点提高，并促进其向六方晶系转化，表征六方晶系结晶熔融的小峰变大，而揉球方式制样测得高倍拉伸ＵＨＭＷ－ＰＥ纤维的ＤＳＣ曲线则出现多重熔融峰。

The samples of UHMW-PE with various drawing ratios were prepared by three methodsi.e.cut, random coil and fixed length and were determined by using DSC respectively.DSC curves of the samples prepared by the three methods are different from one another.The sample prepared by using cut method is under relax state and the small melting peaks of the shish-kebob orthorhombic crystal and hexagonal system appears only.The sample prepared by using fixed length method may restrain the shrink of fibers,and raise the melting temperature of the shish-kebob crystal,and promote the transform of crystal form into hexagonal system and enlarge the melting peak of kexagonal system.The sample prepared by using random coil method makes the fibers shrink partly and the melting bahavious is between the previous two.