Sustainable thermoplastic elastomers based on thermoplastic polyurethane and ground tire rubber

Abstract In this research, blends are prepared of thermoplastic polyurethane (TPU), ground tire rubber (GTR) and its devulcanized version (dGTR). The primary objective is to produce thermoplastic elastomers wherein TPU is partially substituted by GTR or dGTR obtained from used tires, thereby forming a blend with a favorable cost/value ratio and a smaller environmental footprint. Throughout the experiment, the rubber content of the blends is varied between 0 and 50 wt% and the effect on mechanical properties is investigated. The blends are compounded with a twin‐screw extruder, after which sheet samples are produced by injection molding. With a view to a possible future industrial application, it is important that both the compounding and the injection molding of the specimens are easy to perform, even with a 50 wt% filler content. Increasing the amount of rubber phase reduce the tensile strength and elongation at break of the blends. Unfortunately, devulcanization did not significantly improve the properties of the blends. Overall, even at a (d)GTR content of 50 wt%, an elongation at break of 300% is achieved, which allows the use of the blends as thermoplastic elastomers. In addition, dynamic tests show that the rubber phase increases the damping capacity of the samples.