Recycling of Waste Rubber by Thermo-Mechanical Treatment in a Twin-Screw Extruder

The recycling of waste tires is a significant environmental and economic issue. One of the leading recycling routes is the shredding of tires, resulting in the generation of ground tire rubber. This material can be easily introduced into various polymer matrices as a filler, reducing the use of conventionally applied petroleum-based materials. In such cases, it is essential to ensure sufficient interfacial compatibility, which can be achieved by the proper modification of the rubber surface. Different treatments of ground tire rubber aim to activate its surface and introduce functional groups, providing the possibility for interfacial interactions and the incorporation of significant amounts of recycled material. Therefore, in the presented paper, we examined the impact of thermo-mechanical treatment in a twin-screw extruder on the appearance and chemical structure of ground tire rubber. Moreover, for each set of process parameters, the specific mechanical energy required for processing was calculated, providing essential insights for the potential industrial application of the analyzed process. The energy demand should be considered as a very important issue during the development of “greener” processes and materials.