ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
A detailed study of the polymorphism of poly(3,3-dimethyloxetane) was carried out by differential scanning calorimetry and X-ray diffraction. From the relaxed melt state, two modifications, Form II (monoclinic) and Form III (orthorhombic), are separately obtained depending on crystallization temperature. When the crystallization is accomplished for a given modification, this one is stable at any temperature below its melting temperature. However, if the crystallization of a given modification is not complete, the other modification can be crystallized from the amorphous phase. Thus, a possibility of obtaining both forms exists. The kinetic and thermodynamic factors which govern this process are analyzed. The free energies were calculated and the conclusion is that modification II is thermodynamically the most stable one at all temperatures below its melting point.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1985.021860822
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