Combined Effect of High-Temperature Shear Grinding and Gamma-Radiation on the Thermal Properties of Polyethylene
| Autor: | A. T. Kapasharov, Sadulla R. Allayarov, K. D. Semavin, V. G. Nikol’skii, Sergei Demidov, G. V. Malkov, Yu. V. Podval’naya |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
chemistry.chemical_classification 010304 chemical physics Annealing (metallurgy) Polymer Crystal structure Polyethylene 01 natural sciences Grinding law.invention chemistry.chemical_compound Crystallinity chemistry law 0103 physical sciences Melting point Physical and Theoretical Chemistry Crystallization Composite material |
| Zdroj: | High Energy Chemistry. 54:130-135 |
| ISSN: | 1608-3148 0018-1439 |
| DOI: | 10.1134/s0018143920020137 |
| Popis: | During γ-irradiation of polyethylene, its gradual amorphization accompanied by a decrease in the melting point and the heat of melting occurs. Almost complete amorphization of the polymer with crosslinking occurs at a dose of 1400 Mrad according to DSC data. In this case, the polymer retains insignificant crystallinity with a melting heat of 6.2 J/g, which is almost an order of magnitude lower than the melting heat of 118 J/g of unirradiated polyethylene. Depending on the radiation dose, there are three conditional ranges of change in DSC curve parameters: at doses up to 200, from 200 to 800, and over 800 Mrad, associated with different dose dependences of the simultaneously occurring processes of crosslinking and degradation of polymer macromolecules, as well as with radiation annealing of strained areas. High-temperature shear grinding of polyethylene, destroying the crystalline structure, leads to a decrease in the absolute value of the heats of melting and crystallization of the polymer. |
| Databáze: | OpenAIRE |
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