Kinetics of Nanocrystallization in Regular Alternating Terpolymers of Ethene and Propene with Carbon Monoxide
| Autor: | Valery P. Privalko, Antonín Sikora, Eleonora G. Privalko, V. B. Dolgoshey |
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| Rok vydání: | 2003 |
| Předmět: |
Materials science
Polymers and Plastics Crystallization of polymers Kinetics Thermodynamics General Chemistry Condensed Matter Physics law.invention Propene chemistry.chemical_compound chemistry Nanocrystal law Polymer chemistry Materials Chemistry Copolymer Crystallization Glass transition Carbon monoxide |
| Zdroj: | Journal of Macromolecular Science, Part B. 42:953-962 |
| ISSN: | 1525-609X 0022-2348 |
| Popis: | Composition-dependent kinetics of nanocrystallinity development in regular alternating terpolymers of Et and Pr with CO was studied by DSC in the interval between the temperatures of glass transition at T g ≈290 K, and of the onset of endothermal effects of nanocrystals melting at T′ m ≈325 K. Very low levels of nanocrystallinity in the initial, well-aged specimens were tentatively explained by shorter longitudinal dimensions of Et/CO nanocrystals compared to the critical size of chain-folded crystallization nuclei expected for other copolymers. The nanocrystallization half-times exceeded by many orders of magnitude those typical for the melt crystallization of polymers by chain-folding; the best-fit values of the Kolmogorov-Avrami shape parameter n around or below unity were considered consistent with the lateral aggregation of Et/CO blocks as the basic anticipated mechanism of nanocrystallization. In terms of the standard bi-exponential equation for crystallization rate, the extraordinarily slow develop... |
| Databáze: | OpenAIRE |
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