iPP/POE共混物注塑件中POE表面析出机理  

Migration Mechanisms of POE Surfaces in Injection Molding iPP/POE Blends

作　　者：彭莉 刘正英[1] 杨伟[1] PENG Li;LIU Zhengying;YANG Wei(College of Polymer Science and Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学高分子科学与工程学院,四川成都610065

出　　处：《塑料工业》2024年第7期131-137,154,共8页China Plastics Industry

基　　金：国家自然科学基金项目(52125301)。

摘　　要：等规聚丙烯(iPP)与乙烯-辛烯共聚物(POE)共混物注塑件中,POE相向表面析出的驱动力及影响因素尚未有定论。为此,以4种相对分子质量的iPP和POE8137的共混物注塑样品为研究对象,采用扫描电子显微镜、原子力显微镜等形貌表征技术、广角X射线衍射、小角X射线散射等晶体结构表征技术及动态力学分析研究了150℃温度下退火过程中POE的析出行为与影响因素。研究表明,短时间高温退火时,POE的析出程度与基体树脂iPP的分子量有明显关系:即iPP的分子量越高,iPP/POE样品退火后POE的析出程度越高,推测POE的析出机制类似于非晶共混薄膜体系中的表面偏析效应。退火0~4 h时,iPP在该温度下退火发生结构重构,结晶度提高,非晶区平均厚度增加,非晶区的分子链活动性增强,这些因素均有利于促进POE相的析出。退火4 h后,iPP晶体结构重构完成,POE仍继续发生向析出,进一步说明POE的析出机制是表面偏析效应。The driving force and factors affecting the migration of ethylene-octene copolymer(POE)phase onto the surface of isotactic polypropylene(iPP)/ethylene-octene copolymer(POE)blends remain unclear.Thus,injection molding samples of iPP and POE8137 blends with four relative molecular weights were studied.The migration behaviors and influencing factors of POE during annealing at 150℃were investigated by employing the morphological characterization techniques such as scanning electron microscopy,atomic force microscopy,and the crystallographic structural characterization techniques such as wide-angle X ray diffraction and small-angle X ray scattering,as well as the dynamic mechanical analyses.The results show that the degree of POE migration during short-time high-temperature annealing is significantly related to the molecular weight of the matrix resin iPP.The degree of POE migration after annealing is higher when the molecular weight of iPP increases.It is speculated that the migration mechanism of POE is caused by a surface segregation effect,which is similar to that in amorphous blend film systems.Annealing for 0-4 h,iPP undergoes structural reconstruction,resulting to an increase in crystallinity,the average thickness of the amorphous region,and the mobilty of the molecular chains in the amorphous region.These factors promote the POE migration.After annealing for 4 h,the reconstruction of iPP crystal structure is completed,while the migration of POE still continues,which further illustrates that the migration mechanism of POE is the surface segregation effect.

关 键 词：等规聚丙烯/乙烯-辛烯共聚物共混物 表面析出 结构重构 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]