熔体挤出-拉伸iPP薄膜的结晶行为和性能Crystallization Behavior and Mechanical Properties of Melt Extrusion-stretching Isotactic Polypropylene Films
刘忠柱;秦琦;李睢水;郑国强;米立伟;
摘要(Abstract):
通过挤出-拉伸法分别制备了iPP和β成核剂改性iPP薄膜,研究了β成核剂和拉伸速率对薄膜结晶行为和力学性能的影响。采用二维广角X射线衍射、二维小角X射线散射、差示扫描量热法、扫描电镜(SEM)和拉伸试验对薄膜微观结构和力学性能进行了相关分析测试。结果表明:β成核剂的加入使得iPP薄膜中的晶型发生改变;当β成核剂质量分数为0.2%且拉伸速率为30cm/min时,薄膜内部β晶发生明显支化现象,并且在其内部至少形成了三种不同形貌的β晶;试样的断裂伸长率和韧性均增大;随着拉伸速率的增加,试样中β晶含量减小。
关键词(KeyWords): 等规聚丙烯;β成核剂;拉伸速率;结晶行为;力学性能
基金项目(Foundation):
作者(Authors): 刘忠柱;秦琦;李睢水;郑国强;米立伟;
参考文献(References):
- [1]LUO F,GENG C Z,WANG K H,et al.New understanding in tuning toughness ofβ-polypropylene:the role ofβ-nucleated crystalline morphology[J],Macromolecules,2009,42(23):9325-9331.
- [2]LIU Z Z,LIU X H,ZHENG G Q,et al.Mechanical enhancement of melt-stretchedβ-nucleated isotactic polypropylene:the role of lamellar branching ofβ-crystal[J].Poly Test,2017,58(2):227-235.
- [3]ZHU P W,EDWARD G.Orientational distribution of parent-daughter structure of isotactic polypropylene:a study using simultaneous synchrotron WAXS and SAXS[J].J Mater Sci,2008,43(19):6459-6467.
- [4]LIU Z Z,LIU X H,ZHENG G Q,et al.New insight into lamellar branching ofβ-nucleated isotactic polypropylene upon melt-stretching:WAXD and SAXS study[J].J Mater Sci,2015,50(2):599-604.
- [5]CHO K,SAHEB D N,YANG H,et al.Memory effect of locally orderedα-phase in the melting and phase transformation behavior ofβ-isotactic polypropylene[J].Polymer,2003,44(14):4053-4059.
- [6]ZHAO P,WANG K,YANG H,et al.Excellent tensile ductility in highly oriented injection-molded bars of polypropylene/carbon nanotubes composites[J].Polymer,2007,48(19):5688-5695.