剪切改性对长链支化聚丙烯流变性能的影响  

Effect of shear modification on the rheological properties of long chain branched polypropylene

作　　者：罗祎玮[1] 信春玲[1,2] 朱伟林[1] 郑大龙[1] 何亚东[1,2] 

机构地区：[1]北京化工大学机电工程学院,北京100029 [2]北京化工大学教育部高分子材料加工装备工程研究中心,北京100029

出　　处：《北京化工大学学报（自然科学版）》2016年第1期56-61,共6页Journal of Beijing University of Chemical Technology(Natural Science Edition)

摘　　要：利用密炼机对长链支化聚丙烯(LCB-PP)施加剪切,通过改变密炼机转子转速、物料在密炼机中的停留时间,得到了具有不同剪切历程的样品。采用熔体流动速率(MFR)、挤出胀大比(SR)以及动态流变特性等表征方法,研究了剪切改性对于LCB-PP流变性能的影响规律。结果表明,施加剪切历程会使LCB-PP的MFR变大,SR变小,造成低频下的储能模量和复数黏度减小;并且剪切历程越长,流变性能下降越明显。另外,末端效应和ColeCole图等的分析结果也证明了剪切改性过程中长支链发生解缠结和取向现象。To obtain long chain branched polypropylene （LCB-PP） with different shear histories, samples were processed in an internal batch mixer with different rotor speeds and residence times. The effects of shear modifica- tion on the rheological properties of LCB-PP were characterized by melt flow rate （MFR）, swelling ratio （SR） and dynamic rheological data. The results indicate that shear history caused higher MFR and lower SR, as well as lower storage modulus and complex viscosity at low frequency, while longer shear history resulted in greater depression of the rheological properties. In addition, the disentanglement and alignment of side chains along the backbone during shear modification were verified by analyses of terminal behavior and Cole-Cole plots.

关 键 词：长链支化聚丙烯 剪切改性 剪切历程 流变性能 

分 类 号：TQ322.2[化学工程—合成树脂塑料工业]