Vulcanized rubber, due to its superior mechanical properties has long been used in various industries, especially automotive. The rubber industry has evolved and expanded over the years to meet the increasing global demands for tires. Today tires consist of about 19% natural rubber and 24% synthetic rubber, while plastic polymer and metal, filler and additives make up the rest. Over 1.6 billion new tires are produced annually and around 1 billion waste tires are generated. Tires are extensively designed with several complex processes to make them virtually indestructible. Since tire rubber does not decompose easily, their disposal at the end of service life creates a monumental environmental impact. However, waste tire rubber (WTR) consist of valuable rubber hydrocarbon, making its recovery or regeneration highly desirable. The conventional recovery method of WTR tends to produce undesirable products due to the destruction of the polymeric chain and exponentially degenerates the vulcanizates’ physical properties. Since then, multiple devulcanization processes were introduced to effectively and selectively cleave vulcanizate’s crosslinks while retaining the polymeric networks. Different devulcanization methods such as chemical, mechanical, irradiation, biological and their combinations that have been explored until now are reviewed here. Besides, an overview of the latest development of devulcanization by ionic liquids and deep eutectic solvents are also described. While such devulcanization technique provides new sustainability pathway(s) for WTR, the generated devulcanizate also possesses comparable physical properties to that of virgin products. This further opens the possibility of novel circular economic opportunities worldwide.

硫化橡胶，由于其优越的机械性能，长期以来一直用于各种行业，尤其​​是汽车行业。多年来，橡胶工业已经发展壮大，可以满足全球对轮胎日益增长的需求。如今，轮胎由大约19％的天然橡胶和24％的合成橡胶组成，而其余部分则由塑料聚合物和金属，填料和添加剂组成。每年生产超过16亿个新轮胎，并产生约10亿个废轮胎。轮胎经过了广泛设计，并采用了几种复杂的工艺，使其几乎坚不可摧。由于轮胎橡胶不易分解，因此在使用寿命结束时将其丢弃会对环境造成巨大影响。但是，废轮胎橡胶（WTR）由有价值的橡胶碳氢化合物组成，因此非常需要回收或再生。WTR的传统回收方法由于破坏了聚合物链，往往会产生不希望的产品，并且使硫化橡胶的物理性能呈指数下降。从那时起，引入了多种脱硫工艺，以有效和选择性地裂解硫化橡胶的交联，同时保留聚合物网络。到目前为止，我们已经探讨了不同的脱硫方法，例如化学，机械，辐照，生物学及其组合。此外，还概述了离子液体和深共熔溶剂脱硫的最新进展。虽然这种脱硫技术为WTR提供了新的可持续性途径，但生成的脱硫剂也具有与原始产品相当的物理性能。