含原位聚合物核壳粒子聚丙烯共混物的流变学研究  

Rheology Study on Polypropylene Blends with in situ Core-Shell Dispersed Particles

作　　者：李明钊 祝良海 陈锋[1,2] 吴强[3] 上官勇刚[1,2] 郑强[1,2] Ming-zhao Li;Liang-hai Zhu;Feng Chen;Qiang Wu;Yong-gang Shangguan;Qiang Zheng(MOE Key Laboratory of Macromolecular Synthesis and Functionalization,Department of Polymer Science and Engineering,Zhejiang University,Hangzhou 310027;International Research Center for X Polymers,Zhejiang University,Haining 314400;College of Chemistry and Materials Engineering,Zhejiang Agriculture&Forest University,Hangzhou 311300)

机构地区：[1]高分子合成与功能构造教育部重点实验室浙江大学高分子科学与工程系,杭州310027 [2]浙江大学高分子新物质创制国际研究中心,海宁314400 [3]浙江农林大学化学与材料工程学院,杭州311300

出　　处：《高分子学报》2022年第11期1399-1408,共10页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51973192);浙江大学高分子新物质创制国际研究中心资助项目.

摘　　要：制备了含原位聚合物核壳粒子的聚丙烯/乙丙橡胶/高密度聚乙烯(PP/EPR/HDPE)共混物,并通过动态流变方法对其熔体结构稳定性进行了研究.动态时间扫描结果表明,PP/EPR/HDPE共混物具有较好的热稳定性.动态频率扫描结果表明,当EPR含量较低时,共混物中聚合物核壳粒子分散相的存在导致体系的长时松弛行为更加显著.当熔体结构在大应变下遭到破坏后,含核壳粒子分散相的共混物具有比普通PP/EPR共混物更快的结构回复速率,且结构回复速率随着核壳粒子的尺寸增大而加快.通过增大普通PP/EPR体系的EPR含量使其橡胶粒子尺寸与三元共混物中原位聚合物核壳粒子尺寸接近时,两者呈现类似的流变行为,这表明PP/EPR/HDPE体系的熔体结构稳定性源于核壳粒子结构导致的分散相尺寸增大的作用.Polypropylene/ethylene-propylene random copolymer/high density polyethylene(PP/EPR/HDPE)blends with core-shell particles were prepared by melting mixing to study the effects of core-shell particles on rheological behaviors of PP based system.Morphology observation through SEM confirmed the core-shell structure of dispersed particles.Different rheological behaviors were studied by rheometer through dynamic test,stress relaxation test,cycled strain sweep test and modulus recovery test.Results showed PP system with core-shell particles presented obvious long-time relaxation,which was not observed in PP/EPR binary blend with low EPR content.It was believed the obvious long-time relaxation came from interfacial relaxation of dispersed phase with larger size,leading to a relaxation plateau.While for PP/EPR binary blend with low EPR content,relaxation modulus showed a quick drop.The different relaxation behaviors between above samples indicated that the introduction of HDPE in PP/EPR system could enlarge the size of dispersed phase through formation of coreshell particles.Cycled strain sweep test proved that PP/EPR/HDPE had satisfactory structure stability after loading large strain,meaning that materials performance could quickly recover once the external strain was unloaded.It was believed that long-time relaxation and structure stability of PP/EPR/HDPE both resulted from larger dispersed phase.This study proved again that HDPE could work as equivalent rubber in PP system by formation of core-shell particles.

关 键 词：聚合物核壳粒子 聚丙烯共混物 流变行为 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]