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.

由于日益增加的环境问题和广泛采用的向循环经济的过渡，从废物中回收原材料的需求日益增长。对于废旧轮胎，需要不断开发方法和工艺，将橡胶硫化胶脱硫成质量和性能与生胶接近的橡胶制品。目前，最常见的方法是使用商业和典型的脱硫剂在超临界二氧化碳 (scCO _{2 ) 中进行脱硫，因为它在从废橡胶（例如轮胎）中回收生橡胶时效率高且对环境友好。}scCO ₂已被普遍接受为传统液体基脱硫介质的有吸引力的替代品，因为由此产生的脱硫橡胶具有比其他工艺相对更好的质量。例如，当 scCO ₂用于从废旧轮胎（例如卡车轮胎）中回收橡胶，并将回收的橡胶与各种成分的天然天然橡胶（NR）混合，共混物的硫化和机械性能与原始天然橡胶非常接近。常用的脱硫材料（如化学试剂、油和溶剂）的大气毒性和成本使人们能够转向使用更环保（主要是有机物）和容易获得的脱硫化学成分。这篇文献综述文章讨论了对环境产生较小负面影响的橡胶硫化胶化学脱硫方法。一个特别的重点是使用普通有机脱硫剂在 scCO ₂中对废轮胎进行热化学脱硫。