Recycling polypropylene waste packaging

Abstract

This study addresses the use of radiation processing in the reuse of polypropylene (PP) waste derived from municipal products (MSW), evaluating its physical and chemical properties after e-beam (EB) irradiation in a wide range of doses between 12.5 and 500 kGy. The results show that EB irradiation up to 50 kGy has proven more efficient than conventional recycling methods, promoting molecular modifications and achieving convenient molecular rearrangements. Chemical and thermal analyses show the irradiation interference in PP after 25 kGy, and the melting temperature decreased when irradiated with a dose of up to 250 kGy, impacting the morphological and crystallinity phases, due to molecular cross-linking, especially in the PPrec samples. It was observed that the Vicat tests did not interfere with PPrec recycling, for secondary applications. The doses exceeding 100 kGy up to 500 kGy crosslinking allow PP to be a proper material as fillers, industrial applications, or utilized as an energy source, enhancing environmental sustainability. The use of EB in polymer processing presents a significant advantage as an alternative energy source, positioning it as a more sustainable and eco-friendly approach compared to traditional plastic recycling methods.