A Quantitative Model of Super-Arrhenian Behavior in Glass-Forming Polymers
A Quantitative Model of Super-Arrhenian Behavior in Glass-Forming Polymers
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DOI：
10.1021/acs.macromol.8b02413
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发表时间：
2019-02
期刊：
影响因子：
5.5
通讯作者：
G. Medvedev;J. Caruthers
中科院分区：
文献类型：
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作者：
G. Medvedev;J. Caruthers
迁移率的超阿累尼安温度依赖性是玻璃形成聚合物的关键特征，其中随着温度降低至 Tg，迁移率可降低 10 个数量级或更多。已经开发了超阿伦尼行为的基本描述，包括迁移率的压力依赖性。具体来说，log a 迁移率与 B/Hc 成正比，其中 B 是与材料相关的常数，Hc 是液体和玻璃态焓之间的差，该差是根据实验测量的热容量数据确定的。 1/Hc 迁移率模型具有两个材料参数，定量描述了 12 种玻璃形成聚合物的迁移率对温度和压力的依赖性，这些聚合物是唯一有足够实验数据进行分析的聚合物。研究了类似的基于构型的 B/Uc（内能）和 1/TSc（熵）模型。 1/TSc模型，即传统的Adam-Gibbs模型，可以描述1 atm数据...
The super-Arrhenian temperature dependence of the mobility is a key signature of glass-forming polymers, where the mobility can decrease by 10 orders of magnitude or more as the temperature is decreased toward Tg. A fundamental description of the super-Arrhenian behavior has been developed, including the pressure dependence of the mobility. Specifically, the log a mobility is proportional to B/Hc, where B is a material-dependent constant and Hc is the difference between the liquid and glassy enthalpies which are determined from experimentally measured heat capacity data. The 1/Hc mobility model has two material parameters and quantitatively describes the temperature and pressure dependence of the mobility for 12 glass-forming polymers, which are the only polymers where there is sufficient experimental data for analysis. Similar configurational-based B/Uc (internal energy) and 1/TSc (entropy) models were examined. The 1/TSc model, which is the traditional Adam–Gibbs model, can describe the 1 atm data...