Crystallization of poly(ethylene oxide) fractions: Crystallization isotherms
โ Scribed by Beech, D. R. ;Booth, C. ;Dodgson, D. V. ;Hillier, I. H.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1972
- Tongue
- English
- Weight
- 832 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0449-2978
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โฆ Synopsis
Abstract
The crystallization kinetics of a range of fractions of poly(ethylene oxide) are presented and analyzed. It is concluded that deviations from the Avrami equation with exponent of 3 are mainly due to rejection of low molecular weight molecules for the low molecular weight fractions (Mฬ~n~ < 6,000) and to a process of crystal perfecting for the high molecular weight fractions (Mฬ~n~ > 6,000).
๐ SIMILAR VOLUMES
Raman longitudinal acoustic mode (LAM) spectra have been obtained during isothermal crystallization from the melt at various temperatures of a poly(ethylene oxide) (PEO) fraction of molecular weight about 3000 and an a,v-methoxylated fraction (MPEO) derived from it. For both fractions, we find that
The crystallization rates of fractions of poly(ethylene oxide) have been studied microseopically and dilatometrically. Nucleation theory has been adapted to take account of the finite molecular weight and the molecular weight distribution of the fractions. It is found that the free energy of formati