High-Value Recycling of Isotactic Polypropylene-Based Plastic Waste as a Crystallization Promoter for High-Performance Polypropylene Random Copolymers
Qi Wu, Xiangwei Wang, Min Nie, Qi Wang
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.