聚乙烯的动态流变行为分析

Analysis of dynamic rheology behavior of PE

采用动态流变测试研究了角频率、黏度、储能模量、损耗模量、损耗因子等的变化规律,并讨论了它们与聚乙烯分子结构的关系。结果表明:交点模量(G_x)对应的频率越低,聚乙烯的重均分子量越大;G_x的纵向位置越低,聚乙烯的相对分子质量分布越宽;宽分布可以使聚乙烯剪切变稀行为更加明显,但不能排除长支链的影响;通过动态黏度-虚数黏度曲线和损耗因子随角频率的变化可以判断树脂结构中是否含有长支链。

Dynamic rheological tests were conducted to investigate the laws of the angular frequency,viscosity,storage modulus,loss modulus,and loss factors,whose function with the molecular structure of polyethyelene were discussed as well.The results show that the lower the frequency corresponding to module of intersection(Gx)is,the larger the weight average molecular weight of PE is.The lower the longitudinal position of Gx is,the wider the molecular mass distribution of the resin is.Wide distribution can make the resin shear thinning behavior more obvious,but it fails to eliminate the effect of long chain branching.The long-chain branching can be judged by the changes of dynamic viscosity-imaginary viscosity curve and loss factor as a function of angular frequency.