Data/hora: 09/06/2024 02:53:13

Provedor de dados: | Institutional Archive of Ifreme (ArchiMer)
País: | France
Título: | Oxidation of unvulcanized, unstabilized polychloroprene: a kinetic study
Autores: | Le Gac, Pierre Yves; Roux, Gerard; Verdu, Jacques; Davies, Peter; Fayolle, Bruno.
Data: | 2014-11
Ano: | 2014
Palavras-chave: | Polychloroprene; Oxidation; Radical chain; Kinetics.
Resumo: | Thermal oxidation in air at atmospheric pressure, in the 80-140°C temperature range and in oxygen at 100°C in the 0.02-3 MPa pressure range, of unvulcanized, unstabilized, unfilled polychloroprene (CR) has been characterized using FTIR and chlorine concentration measurement. The kinetic analysis was focused on double bond consumption. A mechanistic scheme involving unimolecular and bimolecular hydroperoxide decomposition, oxygen addition to alkyl radicals, hydrogen abstraction on allylic methylenes, alkyl and peroxyl additions to double bonds and terminations involving alkyl and peroxy radicals was elaborated. The corresponding rate constants were partly extracted from the literature and partly determined from experimental data using the kinetic model derived from the mechanistic scheme in an inverse approach. Among the specificities of polychloroprene, the following were revealed: The rate of double bond consumption is a hyperbolic function of oxygen pressure that allows a law previously established for the oxidation of saturated substrates to be generalized. CR oxidation is characterized by the absence of an induction period that reveals the instability of hydroperoxides. The kinetic analysis also reveals that peroxyl addition is faster than hydrogen abstraction but slower in CR than in common hydrocarbon polydienes.
Tipo: | Text
Idioma: | Inglês

Identificador:

http://archimer.ifremer.fr/doc/00199/31010/29413.pdf

DOI:10.1016/j.polymdegradstab.2014.06.019

http://archimer.ifremer.fr/doc/00199/31010/

Editor: | Elsevier Sci Ltd
Formato: | application/pdf
Fonte: | Polymer Degradation And Stability (0141-3910) (Elsevier Sci Ltd), 2014-11 , Vol. 109 , P. 175-183

Fonte:

2014 Elsevier Ltd. All rights reserved.

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