电纺等规聚丙烯纤维诱导同质基体结晶

利用静电纺丝技术得到较细的等规聚丙烯(iPP)纤维,然后将电纺纤维引入到处于过冷态的iPP基体中制备了均质复合体系.重点研究了电纺iPP纤维诱导成核能力.由于纤维和基体同质,所以它们具有完美的晶格匹配及良好的表面润湿性,使电纺iPP纤维有很强的诱导成核能力,且在160℃引入纤维时,界面主要形成α横晶.通过将所制得的复合体系在160℃松弛一段的时间,α横晶再次出现,表明横晶的形成与纤维引入时产生的剪切作用无关.将复合体系熔融再结晶时观察到有"记忆效应"产生,即在原生成横晶的部分区域仍生成横晶,其晶型与最初形成的横晶一致.

Electrospun Isotactic Polypropylene Fiber Induced Transcrystallization of iPP Matrix

The fine iPP fibers were fabricated via electrospining,and then iPP fiber/ iPP composites were prepared through introducing the as-electrospun iPP fibers into supercooled iPP melts.The nucleating ability of the electrospun iPP fibers to the iPP matrix was investigated.When the fibers were introduced at 160 ℃,the transcrystallization layer was mainly composed of α-modification.However,the α-transcrystallization had nothing to do with the shear involved during the fiber introduction,proved by the fact that the relaxed composites at 160 ℃ at different times had no influence on the crystallization form.The results showed that iPP fiber exhibited higher nucleation capacity towards the iPP matrix,which should be associated with the perfect lattice matching and the good wettability.When melting and recrystallizing the iPP fiber/iPP composites,the α-modification iPP partly appeared in original place once more,showing a "memory effect".