【摘要】 为了比较3种基于Adam-Gibbs(AG)理论的焓松弛现象学模型的预测力,文章利用差示扫描量热仪(DSC)分析木糖醇玻璃体系的焓松弛行为,在10 K/min的升温速率下测定经历不同降温速率(0.5～20K/min)的木糖醇在玻璃化转变温度(Tg)前后的比定压热容(cp),并运用Adam-Gibbs-Vogel(AGV)、Gmez Ribelles(GR)和Hutchinson(H)3种现象学模型对实验数据进行曲线拟合。结果表明,3种模型均能很好地重现经历不同降温速率木糖醇玻璃体系实验升温cp曲线,但模型预测的Adam-Gibbs温度(T2)普遍小于由其他实验方法分析(如Williams-Landel-Ferry(WLF)方程分析、介电松弛法等)得到的T2值,H模型对实验数据的预测力强于AGV和GR模型。更多还原

【Abstract】 In order to compare the predictive power of three kinds of enthalpy relaxation phenomenological models based on Adam-Gibbs(AG) theory,the enthalpy relaxation behavior of xylitol glass system was analyzed by differential scanning calorimetry(DSC).A series of specific heat capacity(cp) near the glass transition temperature(Tg) were measured while heating at a rate of 10 K/min as the cooling rate varied between 0.5 K/min and 20 K/min.Three phenomenological models of Adam-Gibbs-Vogel(AGV),Gmez Ribelles(GR) and Hutchinson(H) were used in the curve fitting of experimental data.The results show that all of the three models are able to reproduce the experimental cp curves of xylitol,but the values of Adam-Gibbs temperature(T2) predicted by these models are lower than those by other approaches,such as Williams-Landel-Ferry(WLF) equation analysis and dielectric relaxation analysis.It can be concluded that H model works better than other two models in the presented study.更多还原