高分子熔体和浓溶液的流变性能研究(Ⅲ)线性粘弹性的标度指数与其对起始分子量和测试个数的依赖性

Study on the Rheological Behaviors of Polymer Melts and Concentrated Solutions (Ⅲ) Scalling Exponent of Linear Viscoelasticity and It's Dependence of Primary Molecular Weight Distribution and Testing Number of Polymers

基于多重缠结和多重蠕动模型及高分子熔体内能量耗散机理，高分子熔体的粘弹性是由高聚物起始分子量及其分布和缠结链组（点）在高分子链上的序列分布（N_ijk）三重效应所决定,其三者的统一体现物理量就是高分子链远近程缠结空间的平均限制维数和．又称之为标度指数。根据多重缠结和蠕动粘弹性分子理论，推导出（单分散试样）和（多分散试样），和为第k个高分子体系中i体缠结链组在第j类高分子链上序列分布函数。根据线性粘弹性的定义又计算出η0和η0对起始分子量和分布间定量关系式，并以大量实验结果加以证实。结果表明它们能同实验很好符合。首次证实了和因分子量大小与分布和高聚物品种及所选用的分子量范围而稍有改变等事实。

Based on the m ultiple entanglements and rcptation model and the mechanism ofenergy dispersion, a new relation of linear viscoelastic functions to themolecular weight, molecular weight distribution of primary polymers and the number oftesting polymer system were derived from the theory of viscoelasticity . It is show that the relations are in good agreement with experiments. Basing on the two mechanisms of relaxahon for entanglements on polymer chain, the average constrained dimensional number ofentanglements or scalling exponent in entanglement spacings was derived. It may beexpressed as , where i is the constrained dimensionalijknumber in entanglement spacings, Nijk represent the ith entanglement sequence distribution function on j th polymer chain in k the polymer system. Experimental results showthat the scalling exponent varies with the molecular weight, its distribution of polymer andthe number or lesting polymer system.