Abstract
This article analyzes the features of peroxide modification of recycled polyethylene and polypropylene as one of the promising approaches to improving the quality of recycled polymer materials. The mechanisms of peroxide crosslinking of polyolefins, the influence of organic peroxides and coagents on the formation of a three-dimensional network structure, and the resulting changes in the thermal and mechanical properties of materials are discussed. The efficiency of peroxide modification is shown to depend on the polymer type, peroxide nature and concentration, processing conditions, and the use of coagents. Recycled polyethylene exhibits a higher tendency toward network structure formation, whereas recycled polypropylene is more significantly affected by macromolecular degradation processes. Published data on the influence of peroxide crosslinking on gel content, crystallinity, thermal stability, and the mechanical properties of recycled polyolefins are summarized and analyzed. The obtained results demonstrate the potential of peroxide modification as an effective approach for improving the quality of recycled polyolefins and expanding their application areas. The findings may be used in the development of polymer waste recycling technologies and in the production of materials with enhanced performance properties for the petrochemical industry.