Recycling waste as raw material for powder coatings

Abstract

According to global market analysis, annual production of polymer composites is expected to increase by an average of 6%, reaching a volume of 13-14 million tonnes by 2024, primarily in the building industry and mechanical engineering sectors. Recycling of polymer composites can be achieved through secondary use or recycling of solid waste. In Russia, about 160 out of 343 polymer producers are engaged in polymer recycling, with a focus on thermoplastics. However, recycling of thermoplastics is a complex process due to the strong polymer matrix structure, varying fillers, and resistance to thermal and chemical degradation. Mechanical grinding of waste polymer composites in powder form is a promising way to obtain a secondary product for decorative and protective coatings. Powder coating is a mixture of polymer powders with target and staining pigments, which sprayed onto the surface of a product and then polymerized at 150-220 °С. This paper compares a commercial polymer powder coating with a powder coating derived from recycled glass-reinforced plastic (GRP) on an epoxy binder. The study shows that the polymer powder coating composition obtained from recycled GRP is comparable to commercial powder coatings in terms of uniformity of distribution over the coated surface.