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...
Main Authors: | , , , , |
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Format: | Article |
Language: | English |
Published: |
Sociedade Brasileira de Química
2006-01-01
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Series: | Journal of the Brazilian Chemical Society |
Subjects: | |
Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532006000300027 |
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. |
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ISSN: | 0103-5053 1678-4790 |