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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Chemical Modifications in Styrene-Butadiene Rubber after Microwave Devulcanization

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Author(s):
Hirayama, Denise ; Saron, Clodoaldo [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Escola Engn Lorena, Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Industrial & Engineering Chemistry Research; v. 51, n. 10, p. 3975-3980, MAR 14 2012.
Web of Science Citations: 25
Abstract

Microwave devulcanization has been studied as a method for elastomer recycling, which is based on the conversion of the reticulated and infusible structure of thermosetting rubbers in free polymeric chains able to be remolded by thermomechanical processing in recycling operations for the manufacture of other products. Elastomeric wastes are often irregularly discarded in nature, producing serious environmental damage, and their mechanical recycling is still considered a challenge. Thus, the development of alternatives for elastomer recycling is directly related to the actions of sustainable development and economic benefits to companies that pay to discard their wastes. The aim of this work is to evaluate the chemical modifications occurring in styrene butadiene rubber (SBR) after microwave devulcanization. Compounds of SBR were vulcanized in the presence of vulcanization agents and variable amounts of carbon black, and then the rubbers were milled and submitted to microwave treatment. Only the SBR with high carbon black content shows some portion of devulcanized material. However, the rubber with lower content of carbon black which was devulcanized by microwave radiation shows an increase in cross-link density. The microwave treatment also causes cross-link breaks mainly in polysulfidic bonds as well as decomposition of chemical groups containing sulfur attached to the chemical structure of SBR, while. the chemical bonds of higher energy such as monosulfidic bonds remain preserved. The improvement of the microwave method for rubber devulcanization represents a way for viable recycling of thermosetting rubbers. (AU)

FAPESP's process: 07/07676-9 - Study of the mechanical recycling of PET and tires wastes by FTIR spectroscopy
Grantee:Clodoaldo Saron
Support Opportunities: Regular Research Grants