Devulcanization of styrenebutadiene (SBR) waste tire by controlled oxidation

This work describes the devulcanization of vulcanized SBR (Styrene Butadiene Rubber) based on controlled oxidation with nitric acid. IR, ¹H and 13C-NMR, CHN elemental analyses, TG, GPC and TPD-MS (Temperature Programmed Decomposition-Mass Spectrometry) experiments suggest that nitric acid promotes t...

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Bibliographic Details
Main Authors: Rios Rachel R.V.A., Gontijo Manuela, Ferraz Vany P., Lago Rochel M., Araujo Maria Helena
Format: Article
Language:English
Published: Sociedade Brasileira de Química 2006-01-01
Series:Journal of the Brazilian Chemical Society
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532006000300027
Description
Summary:This work describes the devulcanization of vulcanized SBR (Styrene Butadiene Rubber) based on controlled oxidation with nitric acid. IR, ¹H and 13C-NMR, CHN elemental analyses, TG, GPC and TPD-MS (Temperature Programmed Decomposition-Mass Spectrometry) experiments suggest that nitric acid promotes two processes: (i) devulcanization by oxidation of the sulfide crosslinks and (ii) oxidation of the carbon framework leading to the formation of -COOH and -NO2 groups. Under aggressive conditions (HNO3, reflux) the polymer chain is strongly oxidized and fragmented to a highly oxygenated low molecular weight fraction, which is soluble in water.
ISSN:0103-5053
1678-4790