Portal de Periódicos da CAPES

Effect of irradiation on the degradability of polypropylene in the natural environment

1995; Elsevier BV; Volume: 49; Issue: 2 Linguagem: Inglês

10.1016/0141-3910(95)87014-8

1873-2321

Fumio Yoshii, Gamal A. Meligi, Takashi Sasaki, Keizo Makuuchi, Abdelgawad Rabie, Sei‐ichi Nishimoto,

Microplastics and Plastic Pollution

In order to understand the accelerated degradation of waste plastics in natural environments, the effect of irradiation on the degradation of polypropylene (PP) and PP with a nucleating agent (NA) during storage has been investigated. Relatively low doses in the range 10–30 kGy led to considerable degradation during storage when samples were placed on the roof. The original Mn of 4.49 × 104 (before irradiation) of PP was reduced to 2.8 × 104 on electron beam irradiation of 100 kGy and further reduced to 3.8 × 103 during five months' storage. It was confirmed by chemiluminescence that the degradation during roof storage after irradiation is due to oxidation. NA resulted in the disappearance of elongation of PP by irradiation before storage testing, but the reduction of molecular weight during storage after irradiation was smaller in PP with NA than without NA. This is due to the fact that NA greatly changes the morphology of PP. From these findings, it was demonstrated that the degradation of PP during outdoor storage is accelerated by irradiation. Accordingly, it was concluded that the acceleration in the degradation of irradiated polymer in the natural environment should contribute to the reduction of the load on the environment.