Biodegradable Polymer Composite based on Recycled Polyurethane and Finished Leather Waste

Abstract

The issue of polluting waste has been addressed over the years by means of several methods: depollution, recovery by reuse and/or energy recycling and/or mechanical and/or chemical recycling. In the integrated plastic waste management concept, along with these methods are included the possibilities of reducing the quantities by using biodegradable polymeric materials. The goal paper is to recover footwear waste after use: polymer and finished leather by making new biodegradable polymeric composites. The waste is ground to 1-5 mm and compounded by melt extrusion-granulation, processable by injection into new products (footwear soles) with pre-established advanced features. Biodegradable polymer composite based on post-consumption thermoplastic polyurethane (WTPU) waste compounded with post-consumption finished leather waste, ground and functionalized. This composite will be made into a low-density product, with low cost, recovery and reuse of waste, containing both polymer and protein, 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 of adapting the length of the screw depending on the material (L/D-35). Waste transformation (ground and functionalized) in new value-added products will lead to remarkable improvements in the life cycle of raw materials and the sustainable use of this waste, contributing to sustainability, improving eco-efficiency and economic efficiency and reducing the “pressure” of waste on the environment.