高聚物熔体松弛时间谱的计算

The Calculation of the Discrete Relaxation Time Spectra of Polymer Melts

松弛时间谱是描述聚合物熔体粘弹性质的重要参数 ,它不能通过实验直接获得 .基于聚合物熔体储能模量和耗能模量 ,给出了采用最小二乘线性回归得到熔体松弛时间谱的计算方法 .通过一个算例检验该算法的有效性 ,分析了松弛时间及松弛模态数的选取对计算结果的影响 。

It is well known that the relaxation spectrum characterizes the linear viscoelastic properties of a polymer melt, but the relaxation spectrum is not directly accessible by an experiment. Based on the data of storage and loss moduli the calculation method of the relaxation time spectrum is attained by use of the least square linear regression. The availability of the algorithm is tested by an example.The relaxation time and the number of relaxation mode are very important to the calculation of the relaxation spectra. How to choose the relaxation time and the number of the relaxation mode is analysed in this article and some measures are given to improve the calculation results.