Thermodynamics of the Densification Process for Polymer Glasses
Thermodynamics of the Densification Process for Polymer Glasses
复制标题
聚合物玻璃致密化过程的热力学
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
R. Simha
中科院分区：
文献类型：
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作者：
J. McKinney;R. Simha
定量描述了玻璃在高压下形成的致密化过程。唯象关系的推导，或证明，这允许估计致密化速率κ′（相对于形成压力）从各种热力学量和玻璃化转变行为。此外，应用Simha和Somcynsky的空穴理论，可以方便地估计K′。利用这些关系式估算了κ′，并对玻璃化转变温度为150 ~ 455 K的23种不同有机聚合物的数据进行了比较。致密化的量似乎受到玻璃化温度和有效分解温度随压力增加而明显收敛的限制。给出了极限值的一些估计。最后，由致密化引起的折射率的变化估计从观察到的，或预测，致密化率。
A quantitative description is given for the densification process of glasses resulting from glass formation at elevated pressures. Phenomenologieal relations are derived, or justified, which allow estimation of the densification rate κ′ (with respect to formation pressure) from various thermodynamic quantities and glass transition behavior. In addition, the estimation of K′ may be facilitated by the application of the hole theory of Simha and Somcynsky. Using these relations κ′ is estimated, and the results from the different methods are compared for data from 23 different organic polymers with glass transition temperatures ranging from 150 to 455 K. The amount of densification appears to be limited by the apparent convergence of the glass temperature and effective decomposition temperature with increasing pressure. Some estimates of limiting values are presented. Finally, changes of refractive index resulting from densification are estimated from the observed, or predicted, densification rates.