Konstantinou Pavlina C, Stephanou Pavlos S
Department of Chemical Engineering, Cyprus University of Technology, P.O. Box 50329, 3603 Limassol, Cyprus.
Polymers (Basel). 2023 Aug 7;15(15):3322. doi: 10.3390/polym15153322.
Based on the Generalized bracket, or Beris-Edwards, formalism of non-equilibrium thermodynamics, we recently proposed a new differential constitutive model for the rheological study of entangled polymer melts and solutions. It amended the shortcomings of a previous model that was too strict regarding the values of the convective constraint release parameter for the model not to violate the second law of thermodynamics, and it has been shown capable of predicting a transient stress undershoot (following the overshoot) at high shear rates. In this study, we wish to further examine this model's capability to predict the rheological response of industrial polymer systems by extending it to its multiple-mode version. The comparison with industrial rheological data (High-Density Polyethylene resins), which was based on comparison with experimental data available in (a) Small Amplitude Oscillatory shear, (b) start-up shear, and (c) start-up uniaxial elongation, was noted to be good.
基于广义括号，即贝里斯 - 爱德华兹非平衡热力学形式体系，我们最近提出了一种新的微分本构模型，用于研究缠结聚合物熔体和溶液的流变学。它修正了先前模型的缺点，即该模型对对流约束释放参数的值要求过于严格，以至于不违反热力学第二定律，并且已经证明它能够预测高剪切速率下的瞬态应力下冲（跟随上冲）。在本研究中，我们希望通过将该模型扩展到多模式版本，进一步检验其预测工业聚合物体系流变响应的能力。与工业流变数据（高密度聚乙烯树脂）的比较基于与（a）小振幅振荡剪切、（b）起始剪切和（c）起始单轴伸长中可用的实验数据的比较，结果显示良好。
