Prediction of the flow‐induced crystallization in high‐density polyethylene by a continuum model |
| |
Authors: | Fengyuan Yu Hongbin Zhang Zhigang Wang Wei Yu Chixing Zhou |
| |
Affiliation: | 1. School of Chemistry and Chemical Technology, Advanced Rheology Institute, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China;2. CAS Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China |
| |
Abstract: | In this work, the isothermal flow‐induced crystallization (FIC) of high‐density polyethylene (HDPE) under a simple shear flow was investigated. Two experimental modes, including steady shear and preshear treatment, were performed on the polymer melt. Based on the nonequilibrium thermodynamic theory, the FIC process of HDPE was predicted through the modification of a continuum FIC model. The theoretical predictions of the evolution of both the viscosity in steady shear flow and the complex modulus under preshear treatment were essentially related to the crystallinity of HDPE, in agreement with the experimental findings. Both experimental and predicted results showed that the applied flow field could accelerate the crystallization kinetics of HDPE significantly. However, the effect of the intensity of shear flow on the crystallization of HDPE was finite, showing a saturation phenomenon, namely, the accelerated degree of crystallization tending to level off when the shear rate was large enough. In additional, it was found that the predicted crystallinity of HDPE was very low in induction period either in steady shear flow or by preshear treatment. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 531–538, 2009 |
| |
Keywords: | crystallization crystallization kinetics HDPE kinetics (polym.) modeling polyethylene (PE) preshear flow rheology shear steady shear flow |
|
|