等规聚丙烯纤维结构与性能研究——中粗旦FDY成型过程中的结构变化

STUDY ON THE STRUCTURE AND PROPERTY OF IPP FIBER——STRUCTURE CHANGES OF MID-COARSE FDY IN FORMING PROCESS

本文主要对中粗旦聚丙烯 FDY 在成形过程中结构与性能的变化作了详细地研究。X-射线衍射、扫描电镜、DSC、纤维取向因子等测试结果表明,随拉伸倍数的提高,纤维的断裂伸长线性下降,而强度在拉伸5.8倍时出现极大值;纤维的取向度随拉伸倍数的提高线性增大,计算机分峰结果表明,在高应力状态下,纤维中次晶的生成速率大于α晶。随着拉伸倍数的不断提高,纤维逐渐出现裂缝、微孔及原纤化,结构的破坏导致纤维强度的下降。

The variations of structures and properties in fiber forming for mid-coarse polypropylene FDY areinvestigated by means of X-ray diffraction,scanning electron microscope(SEM),differential scan-ning calorimetry(DSC)and sonic orientation test.It is found that withe the increase ot drawn ratiothe elongation at rupture decreases linearly,the strength increases before 5.8 times and then decreas-es.With increaing draw ratio,the degree of orientation increases linearly,the crystalinity comes up toa maxmum at 5.2 times and then decrease.The resolved calculation of X-ray diffraction curvesshows that the growth rate of paracrystal is larger than that of a-crystal at high stress.At high drawnration the morphology is destroyed,therefore,the strength of the fiber decreases.