Biodegradable Polymer Composite Based on Polyvinyl Chloride and Poly (Ethylene-Vinyl Acetate) Waste

This paper presents experiments on developing and characterizing biodegradable polymer composites based on polyvinyl chloride and expanded poly(ethylene vinyl acetate) (EVA) post-consumer waste. This type of waste is a thermoplastic material collected from the footwear industry, residues from the production of outer and intermediate soles and used footwear. It is used due to its shock absorption properties and low density (0.6-0.8 g/cm3). To make these products, EVA is injected into molds, a process that generates waste that cannot be reused. In this paper, a method of EVA waste recovery is presented and the possibility of developing a recycled product is investigated. Expanded EVA waste is cryogenically ground to sizes of min. 500 nm, functionalized by a mechanical process at temperature with polydimethylsiloxane (PDMS) and mixed in the composite in various proportions (10, 20, 50%). This composite will be made into a low-density product, with low cost, recovery and reuse of waste, 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 performed on an extruder-granulator. The experimented biodegradable composites were physico-mechanically characterized. Waste transformation (ground and functionalized) into 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.