Environmentally friendly polymer-rubber composites obtained from waste tyres: A review

The paper is transdisciplinary. The complex overview on changes in policy and approach to waste tyres that leads to both solving environmental problem of post-consumer tyres and creating environmentally friendlier novel materials are presented. It is shown that in the world, the amount of polymer wastes increases every year. Most of them are in the form of post-consumer tyres. Recycling and recovery of such tyres is a serious environmental problem due to their very complex structure and composition. Moreover, storage of the whole post-consumer tyres takes a lot of space in landfills and pollute the environment. However, recently it has been reported a great progress in sustainable management of waste tyres. An important role in the progress of tyre recovery has played the establishment of the restrictive regulations, which prohibits stockpiling of tyres in landfills. This legislative steps have contributed to significant impact on the progress in the development of car tyres recovery. The most important is introducing of monitoring for improper stockpiling, producer responsibility for wastes tyres and the new tax system. With the help of mentioned changes and introducing environmentally friendlier technologies it appeared that the utilization of tyres can be cost effective. The applied technology can transform post-consumer tyres into a source of energy or valuable raw materials, from which can be obtained a wide range of sustainable polymeric composite materials characterized by quite good mechanical and functional properties. This new approach to post consumer tyres is undertaken in U.S., China, Japan and EU. From the overview it is clear that the grinded used tyres should not be treated any more as a pollutant but rather as a source of sustainable materials. Those materials belong to modern polymer-rubber composites obtained mainly from elastomers (natural and synthetic rubbers) or thermoplastics (PE, PP, PVC). The very important factor in making good composites is get the knowledge about the influence of amount, size and morphology of rubber granulate grains on interactions that occur in composites between the polymer matrix and tyre rubber grains and thus the properties. That last item was discussed in the final part of the overview.