Mechanochemical Recycling and Processing of Waste Crosslinked Polymers: Waste Tire Rubber and Waste Xlpe from Cable Scraps

The accumulation and disposal of polymer wastes including waste plastics, waste rubber, waste synthetic fibers and waste composites is a worldwide concern. Until now, there are many technical barriers in recycling polymer wastes with crosslinked structure, such as vulcanized rubber, crosslinked polyolefine and other thermoset materials. In this study, a mechanochemical approach was used to conduct the devulcanization of waste tire rubbers (WTR) and de-crosslinking of waste crosslinked polyethylene (XLPE) from cable scraps, for turning WTR and waste XLPE to re-formable materials. The stress-induced mechanochemical devulcanization of waste tire rubber and decrosslinking of XLPE at ambient temperature can be achieved through self-designed solid-state mechanochemical reactor. Several high-valued composites, such as natural rubber/WTR, nitrile rubber/WTR, HDPE/XLPE, thermoplastic vulcanizates (TPVs) from partly de-crosslinked XLPE scrap and partly devulcanisized WTR, with improved mechanical properites were obtained through mechanochemical processing. The objective of the present research is to develop a feasible technique for reusing unsegregated waste crosslinked polymer materials.