Experimental information on the viscosities, η, of polymer solutions and of polymer melts as a function of shear rate is modeled by means of an approach that describes the diminution of ln η as a function of shear stress, τ, in terms of an exponential decay. The approach uses the following three adjustable parameters: the zero‐shear viscosity of the system, a characteristic shear stress, quantifying its susceptibility toward shear thinning, and a dimensionless parameter stating the magnitude of the effect. This procedure gives access to the Newtonian behavior also in cases where direct measurements are impractical or impossible; it discloses two phenomena not reported so far: a qualitative change in the efficacy of τ at a characteristic concentration and indicates the occurrence of two different disentanglement mechanisms in thermodynamically unfavorable solvents.

中文翻译：

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剪切稀化：通过非牛顿地区的测量确定零剪切粘度

关于聚合物溶液和聚合物熔体的粘度η与剪切速率的函数关系的实验信息是通过一种方法建模的，该方法描述了lnη随剪切应力τ的函数的指数衰减。 。该方法使用以下三个可调参数：系统的零剪切粘度，特征剪切应力，量化其对剪切稀化的敏感性以及无量纲参数说明影响的大小。在直接测量不可行或不可能的情况下，该程序还可以访问牛顿行为。它揭示了两种目前尚未报道的现象：