【作者】 陈放； 郭朝霞； 于建；

【Author】 CHEN Fang;GUO Zhaoxia;YU Jian;Key Laboratory of Advanced Materials(MOE),Department of Chemical Engineering,Tsinghua University;

【机构】 清华大学化工系先进材料教育部重点实验室；

【摘要】 <正>聚合物纳米合金一般是指分散相尺寸小于100纳米的合金,因其特殊的微观结构与优异的性能受到领域内学者们的关注。本课题组之前的工作中通过向iPP粒料中扩散单体苯乙烯(St)引发聚合的方法,实现了iPP/PS聚合物纳米合金的制备。本文从反应动力学的角度,研究苯乙烯在聚丙烯粒料中的聚合反应过程。在扩散聚合开始后一定时间向体系内添加过量的阻聚物质,有效地终止反应,研究合金粒料中PS含量、PS的分布与PS分散相形态随时间更多还原

【Abstract】 Nanoblends,in which the dispersed-phase domains exhibit length scale of 100 nm or less,is of growing interest due to the potential for enhanced properties.In the previous work of our group,iPP/PS nanoblends were prepared by the polymerization of styrene in PP pellets.In this paper,polymerization kinetics of styrene in PP pellets is studied.After terminating the polymerization at certain time,the changes of PS content,PS distribution and dispersed phase morphology in pellets with polymerization time were studied.Polymerization rate of styrene in PP pellets is relatively high.After initiation,autoacceleration occurs at 30 min to 60 min caused by restricted movement of macroradicals.The curve of PS distribution as a function of the distance from one end of the diameter gradually turn from "-" shape(30 min) with even distribution to "M" shape(180 min) with a nearly homogeneous distribution of PS inside the pellet and an increase of PS on approaching the pellet edge.Dispersed phase size increases from nanoscale to submicron level size from 30 min to45 min,and dispersed phase morphology becomes coexisting of micron level size and nanoscale phase at last.This study allows us to know the nanostructure of the alloy pellets at certain polymerization time,and thus has an important significance in design and preparation of nanoblends with different nanostructures.更多还原