COMPARISON OF THE DEGRADABILITY OF IRRADIATED POLYPROPYLENE AND POLY(PROPYLENE-CO-ETHYLENE) IN THE NATURAL-ENVIRONMENT

Evaluation of the degradability of irradiated polymers under natural e nvironmental conditions may give useful information about the possible rapid degradation of waste polymer materials for environmental conser vation. The degradability in various environments of poly(propylene-co -ethylene), CPP, after irradiation has been investigated. The degradab ility of the CPP in the natural environment, evaluated by strength and elongation tests, during storage after irradiation was slower than th at of polypropylene (PP). Thus, CPP required a larger dose to achieve the same degradability as PP. However, molecular scission of the CPP d uring roof storage was almost the same as that of PP. The CPP has a lo wer crystallinity and a smaller spherulite size than PP. Thus, the deg radability measured by the tension test of irradiated CPP during stora ge was different from that of PP. However, it was confirmed that irrad iation was effective in accelerating degradation of CPP during outdoor storage.