An overview on waste rubber recycling by microwave devulcanization

This review deals with waste rubber recycling by devulcanization treatment using microwave method. In fact, vulcanized rubbers have been extensively used in various fields due to their superior performances. Subsequently, the massive use of such materials, especially in the automotive industry, has generated a substantial amount of wastes which are not easily to be degraded due to the three-dimensional network formed by the vulcanization process. One of the optimal solutions for the successful recycling of rubber is devulcanization, i.e., the process in which the sulfur bonds in the vulcanized material are selectively broken. Currently, to achieve rubber devulcanization, the microwave treatment has been proposed as a promising alternative process due to its precise manipulation of process variables. Furthermore, the microwave process is easily to be coupled with effects of other elements such as chemical and swelling agents. In this work, different microwave devulcanization methods are reviewed, the utilization of the corresponding devulcanized materials has also been discussed. The reviewed contents are believed to be of great interest to academics and industries since they represent a great challenge from scientific, economic and environmental points of view.