The characterization of the time-dependent nonlinear viscoelastic of an LDPE melt using a simple thixotropy model

• 来源期刊: 力学学报（英文版）
• 年，卷（期）: 2005,（4）
• 页码范围: 330-335
• 页数: 6页
• 语种: 英文

摘要

A new simple thixotropy model was proposed in the present paper to characterize the thixotropy-loop experiments and the start-up experiment of an LDPE (PE-FSB23D022/Q200) melt. The thixotropy model is a combination of a viscoelastic-component and a postulated kinetics process of structure change, which is constituted in terms of the indirect microstructural approach usually adopted in the characterization of thixotropy. The descriptions of the thixotropy model on both the thixotropy-loop tests and the startup test show good agreement with the experimental values, indicating the good capability of the model in characterizing the time-dependent nonlinear viscoelastic. The stress overshoot phenomenon and the stress relaxation after cessation of the thixotropy loop test can be described well by the model, whereas both of the typical viscoelastic phenomena could not be described in our previous work with a variant Huang model.