论文部分内容阅读
对某些中等浓度聚合物溶液,在它们的不同流变函数之间,存在一条重要的经验定律,即Cox—Merz关系式。另一方面,对该类溶液,已知其动态流变性能(G′、G″),可通过Rouse谱加以解释。在Rouse模型理论中,如果在溶液的两种速度场之间——微观分子链附近的溶剂速度场和宏观可测量的溶液平均速度场之间引入一种与宏观速度梯度▽■相关的滑动函数,则理论的预言能力大为改善,而这种滑动函数可通过Cox-Merz关系式加以确定。本工作介绍了非仿射变形假定和滑动函数的基本概念,为一类浓度适中的聚合物溶液确定滑动函数的形式,作为推论,进一步确定了剪切流场中的物质函数——ψ_1、ψ_2、η~+、η~-。一些公开发表的实验数据被引证,与理论结果吻合良好。
For some medium-strength polymer solutions, there is an important empirical law between their different rheological functions, the Cox-Merz relationship. On the other hand, the dynamic rheological properties (G ’, G ") of these solutions are known and can be explained by the Rouse spectrum. In the Rouse model theory, if between two velocities of the solution - microscopic The introduction of a sliding function related to the macro-velocity gradient ▽ ■ between the solvent velocity field near the molecular chain and the macroscopically measurable solution velocity field greatly improves the theoretical predictive power which can be obtained by Cox- Merz equation.The basic concepts of non-affine deformation assumptions and sliding functions are introduced in this work, and the form of sliding function for a moderate concentration of polymer solution is determined. As a corollary, the material in shear flow field is further confirmed Functions --ψ_1, ψ_2, η ~ +, η ~ - Some published experimental data are cited and agree well with the theoretical results.