High-Value Recycling of Isotactic Polypropylene-Based Plastic Waste as a Crystallization Promoter for High-Performance Polypropylene Random Copolymers

Abstract

Highly efficient recycling of nonrenewable resources is increasingly important at the global concern of resource crisis and environmental issue. Here, a new strategy for value-added application of isotactic polypropylene (iPP)-based plastic waste as a crystallization promoter was proposed, and cigarette packaging film (CPF) waste as a typical single-component iPP was used as a representative example to demonstrate the successful application. First, the CPF wastes were pulverized into ultrafine powders under three-dimensional shearing force generated by solid-state shear milling equipment. Then, the CPF powders as a crystallization promoter were incorporated into a polypropylene random copolymer (PPR) in the presence of a β-nucleator by utilizing high-chain stereoregularity and strong crystallization nature to cultivate rich β-crystals. Finally, the outstanding combination of strength and toughness of the as-prepared PPR sample was exemplified by the increases of 66 and 25.8% in elongation at break and impact strength over a pure PPR sample at the guarantee of mechanical strength. This simple blending approach also can be extended easily to the recycling of the other polypropylene-based waste plastics and thus is an important step toward solving global plastic pollution.