Organic chemical devulcanization of rubber vulcanizates in supercritical carbon dioxide and associated less eco-unfriendly approaches : A review

There is a growing need to recover raw materials from waste due to increasing environmental concerns and the widely adopted transition to circular economy. For waste tyres, it is necessary to continuously develop methods and processes that can devulcanize rubber vulcanizates into rubber products wit...

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Publié dans:Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA. - 1991. - 40(2022), 5 vom: 08. Mai, Seite 490-503
Auteur principal: Gumede, Jabulani I (Auteur)
Autres auteurs: Hlangothi, Buyiswa G, Woolard, Chris D, Hlangothi, Shanganyane P
Format: Article en ligne
Langue:English
Publié: 2022
Accès à la collection:Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA
Sujets:Journal Article Review Supercritical carbon dioxide devulcanization devulcanizing agents eco-friendly waste tyre recycling reclamation Organic Chemicals Carbon Dioxide 142M471B3J plus... Rubber 9006-04-6
Description
Résumé:There is a growing need to recover raw materials from waste due to increasing environmental concerns and the widely adopted transition to circular economy. For waste tyres, it is necessary to continuously develop methods and processes that can devulcanize rubber vulcanizates into rubber products with qualities and properties that can closely match those of the virgin rubber. Currently, the most common, due to its efficiency and perceived eco-friendliness in recovering raw rubber from waste rubbers, such as tyres, is devulcanization in supercritical carbon dioxide (scCO2) using commercial and typical devulcanizing agents. The scCO2 has been generally accepted as an attractive alternative to the traditional liquid-based devulcanization media because of the resultant devulcanized rubber has relatively better quality than other processes. For instance, when scCO2 is employed to recover rubber from waste tyres (e.g. truck tyres) and the recovered rubber is blended with virgin natural rubber (NR) in various compositions, the curing and mechanical properties of the blends closely match those of virgin NR. The atmospheric toxicity and cost of the commonly used devulcanization materials like chemical agents, oils and solvents have enabled a shift towards utilization of greener (mainly organic) and readily available devulcanization chemical components. This literature review paper discusses the approaches, which have less negative impact on the environment, in chemical devulcanization of rubber vulcanizates. A special focus has been on thermo-chemical devulcanization of waste tyres in scCO2 using common organic devulcanizing agents
Description:Date Completed 20.04.2022
Date Revised 20.04.2022
published: Print-Electronic
Citation Status MEDLINE
ISSN:1096-3669
DOI:10.1177/0734242X211008515