双向拉伸过程中聚丙烯薄膜结构与性能的演变

Evolution of Polypropylene Film Structure and Properties during Biaxial Stretching

通过同步双向拉伸方法制备了双向拉伸聚丙烯(BOPP)薄膜,研究了不同拉伸倍数下双向拉伸过程中BOPP薄膜的结构和性能演变。结果表明,双向拉伸过程中取向诱导结晶与取向过程中晶区的破碎并存,最终导致结晶度随双向拉伸倍数的增加变化不大;取向度随拉伸倍数的增加而显著增加,且较高的拉伸倍数下可以有效地减少薄膜中应力集中区域的面积,提升BOPP薄膜的取向均匀性;双向拉伸倍数的增加对BOPP薄膜力学性能影响显著。

Biaxially oriented polypropylene(BOPP)films were prepared by simultaneous biaxial stretching method,and the evolution of the structure and properties of BOPP films during biaxial stretching at different drawing ratio was investigated.The results show that orientation-induced crystallization and fragmentation of crystalline regions during the biaxial stretching process coexist,which ultimately leads to little change in crystallinity with the increase of drawing ratio.The orientation increases significantly with the increase of drawing ratios,and the higher drawing ratios can effectively reduce the area of stress concentration region in the film and improve the orientation uniformity of BOPP film.The increase of drawing ratio has a significant effect on the mechanical properties of BOPP film.