Microwave treatment in waste rubber recycling – recent advances and limitations

Environmentally-friendly microwave heating is increasingly used in polymer chemistry and technology. The selectivity and highly efficiency in the heat transfer present a huge advantage in systems based on recycling, improving theirproductivity and economic competitiveness. In case of the industrial recycling of waste rubbers, especially end-of-life tires,microwave-induced devulcanization and pyrolysis are nowadays considered as promising approaches. This work aims toreport the recent progress in microwave treatments of vulcanized rubbers with different compositions. Special attention isfocused on the correlation between microwave processing parameters and devulcanization/pyrolysis efficiency, which havea significant impact on the structure-property relationships of the obtained products. Moreover, the main challenges affectingthe future of the industrial application of the microwave technology in rubber recycling are also discussed.