A Quantitative Model of Super-Arrhenian Behavior in Glass-Forming Polymers
| Autor: | Grigori A. Medvedev, James M. Caruthers |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Mobility model Materials science Polymers and Plastics Internal energy Organic Chemistry Thermodynamics 02 engineering and technology Polymer Pressure dependence 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Heat capacity Quantitative model Glass forming 0104 chemical sciences Inorganic Chemistry Temperature and pressure chemistry Materials Chemistry 0210 nano-technology |
| Zdroj: | Macromolecules. 52:1424-1439 |
| ISSN: | 1520-5835 0024-9297 |
| Popis: | 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... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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