Waste Rubber Recycling Technologies and Reclaimed Rubber Applications

Abstract

Waste rubber has emerged as a critical global concern, with its annual production skyrocketing. These discarded rubber products, resistant to decomposition, not only consume vast land resources but also release harmful substances, polluting soil and groundwater. Moreover, they pose a high - risk fire hazard and emit foul odors, severely degrading the surrounding environment. Simultaneously, as rubber resources are scarce, over 70% of natural rubber in China relies on imports. This review delves into the evolution of reclaimed rubber production technologies, from the 1846 lime chloride boiling method—plagued by pollution and low yields—to contemporary physical (microwave, ultrasound, twin - screw extrusion), chemical, biological, and thermochemical methods. New - age green technologies like supercritical devulcanization are enhancing eco - friendliness and production efficiency. Applications in building materials (such as asphalt modification and rubber concrete) and as fillers in rubber products are also explored. These technologies not only enhance resource utilization by converting waste into value - added materials but also adhere to circular economy principles, supporting environmental protection and contributing to carbon neutrality and the UN Sustainable Development Goals.