【摘要】 对聚对苯二甲酸乙二醇酯(PET)进行不同频率下的温度扫描试验和不同温度下的频率扫描试验，得到PET材料的玻璃化转变温度及动态黏弹性参数随测试温度、频率的变化特性。根据时间-温度等效原理构建出宽广频域的PET动态黏弹性主曲线，得到相应的移位因子，利用WLF方程对温度移位因子进行拟合，拟合结果与试验结果吻合较好。此外，研究表明，PET损耗模量主曲线和损耗因子主曲线均呈现明显的峰值，且峰值两边具有非对称性，因此，引入改进的分数阶Zener模型(mFDZ)对PET的动态黏弹性试验主曲线进行综合分析，通过建立合适的目标函数，基于Matlab平台对mFDZ模型进行参数识别，得到了统一的模型参数值。根据得到模型参数计算的mFDZ模型曲线与PET黏弹性试验主曲线、非对称的Cole-Cole曲线及Wicket曲线均吻合良好，这表明，mFDZ模型能较好地描述PET材料动态黏弹性的非对称性，可适用于描述PET材料在宽广频域内的动态黏弹性能。更多还原

【Abstract】 The temperature scanning tests and frequency scanning tests were performed on Polyethylene terephthalate(PET) material to obtain the glass transition temperature and dynamic viscoelastic properties varying with the test temperature and frequency. According to the time-temperature superposition principle, dynamic viscoelastic master curves of PET were constructed, and the corresponding shift factors were obtained. The WLF equation was used to fit the temperature shift factors, and the fitting results were in good agreement with the experimental results. Moreover, the modified fractional Zener model(mFDZ) was introduced to analyze the dynamic viscoelastic test curves of PET. An appropriate objective function was established, the model parameters were identified and optimized iteratively using Matlab optimization toolbox, and the unified model parameter values were accurately obtained. The mFDZ model curves calculated according to the model parameters were in good agreement with the dynamic viscoelastic master curves, Cole-Cole curve and Wicket curve of PET material. It showed that the mFDZ model could well describe the asymmetry of the dynamic viscoelasticity, and can be used to describe the dynamic viscoelasticity of PET materials in a wide frequency domain.更多还原