Biodegradable polymeric composite based on recycled polyurethane and rubber wastes: material for green shoe manufacturing

This paper presents the process of obtaining biodegradable polymeric composites based on post-consumption thermoplastic polyurethane and post-consumption vulcanized rubber waste, in various ratios (5, 10, 20, 30, 50%), cryogenically ground to min. 100 nm, and maleic anhydride grafted polyethylene as compatibilizer between the two phases. This composite will be formed into a low-density product, with low cost, recovery and reuse of waste, containing post-consumption polymers, and last but not least, biodegradable. The methodology for making the new materials involves the following steps: sorting waste, grinding, functionalization and compounding. These operations are easy to manage and do not involve new equipment. Compounding, the most important operation, will be carried out on a corotating twin-screw extruder-granulator with the possibility to adjust parameters such as temperature and speed depending on the material, having a screw ratio (L/D-35). The tested biodegradable composites were characterized structurally and physico-mechanically. Waste transformation (ground and functionalized) into new value-added products will lead to remarkable improvements in the life cycle of raw materials and the responsible use of this waste, contributing to sustainability, improving eco-efficiency and economic efficiency and reducing the “pressure” of waste on the environment.