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Etude cinétique de la dégradation du poly(oxytétraméthylèneoxytéréphtaloyle)

✍ Scribed by Devaux, Jaques ;Godard, Pierre ;Mercier, Jean-Pierre

Publisher
Wiley (John Wiley & Sons)
Year
1978
Weight
398 KB
Volume
179
Category
Article
ISSN
0025-116X

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✦ Synopsis

Abstract

The kinetics of thermal degradation of poly(oxytetramethyleneoxyterephthaloyl) was studied. This polyester undergoes a pyrolysis reaction in the temperature range of processing via a statistical mechanism proceeding by a random scission of the carbon‐oxygen bondings. This phenomenon is characterized by an energy of activation of 189,2kJ/mol (45,2kcal·mol^−1^) and by a negative entropy of activation [−20,3J·mol^−1^·K^−1^ (−4,84cal·mol^−1^·K^−1^)]. Like most of the esters with a hydrogen atom in β position, this polyester undergoes degradation by an intramolecular mechanism involving the formation of a cyclic transition state. The very high value of the degradation constant of this polycondensate is probably a result of the presence, in this chain, of the very flexible tetramethylene segment.

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