Accelerated environmental degradation of gamma irradiated polypropylene and thermal analysis

Abstract

Polypropylene (PP) is one of most important plastic commodities in the world. It can be used in many applications due to its relation of outstanding properties at low cost. However, PP has very low environmental degradation rate, therefore the discarded PP can accumulate in the environment. The aim of this study is the degradation control of PP using gamma radiation. Dumbbell samples were manufactured by injection molding and after irradiated using gamma radiation with different doses: 5 kGy, 12.5 kGy and 20 kGy. The irradiated samples were exposed to environmental aging during 90 days and characterized by Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TG) and Differential Scanning Calorimetry (DSC). The dumbbell samples PP 5 kGy, 12.5 kGy and 20 kGy, exposed to environmental aging, showed intense oxidation with presence of surface cracks compared with the PP non-irradiated.