摘要
利用高级流变扩展系统(ARES)研究了碳黑(CB)填充的高密度聚乙烯—乙烯和醋酸乙烯共聚物(HDPE/EVA)体系的流变学行为。研究发现在高填充份数时低频区出现似固体的“第二平台”、损耗因子峰以及强剪切变稀行为,这些现象的出现均与CB颗粒之间以及颗粒和高分子链之间的相互作用所形成的网络结构有关。通过粘度随碳黑含量的变化可以看出,当填充碳黑的量达到20 phr时体系即出现所谓的“流变逾渗”结构。体系在辐照之后流变学行为与辐照前相比发生了很大的变化:在低频区的损耗因子峰消失,储能模量(G′)对频率的依赖关系减小,显示辐照对聚合物分子产生交联作用。而高剂量下模量的微小回复估计与聚合物分子的部分降解有关。
The rheological property of HDPE/EVA system filled with carbon black （CB） is studied with Advanced Rheology Expand System （ARES）. It is found that the appearance of the solid-like ＂second plateau＂ and the peak of loss factor in the low frequency region as well as the strong shear thinning effect are all related to the network formed by the interactions between particles and particles/polymer chains. The accelerated increase of complex viscosity with increasing of filler loading above 20 phr indicates that a rheological percolation structure of the filler has formed. Irradiation with gamma-ray affects the rheological behavior of the system greatly, i.e., the peak of loss factor disappears and the dependence of the G＇ on frequency becomes smaller, indicating cross-linking of the polymer molecules. At dose of 100 kGy an abnormal behavior is observed which can be partly attributed to the degradation of polymers.
出处
《核技术》
EI
CAS
CSCD
北大核心
2007年第4期361-365,共5页
Nuclear Techniques
基金
中国科学院上海应用物理研究所<人才引进项目>(90120432)资助
