The Effects of Gamma Radiation on the Microstructure and Mechanical Properties of Polypropylene

Abstract

In this study, polypropylene (PP) samples were manufactured using the hot-pressing technique. The influence of gamma ray irradiation exposure time (0, 2, 4, and 6 hours) on the microstructure and mechanical properties of commercial polypropylene (PP) has been investigated using an optical microscope and tensile test. All the samples were subjected to gamma irradiation in the presence of air. The microstructure and tensile tests were performed for non-irradiated and irradiated samples. The results show that the microstructure of polypropylene changes from a rough surface to fracture-like defects at 2, 4, and 6 hours. The stress and strain of polypropylene (PP) are increased markedly at an exposure time of 4 hours. It is identified that the tensile stress and strain have increased to 21.5 MPa and 7.2%, respectively, which amounts to an improvement of 30.3% and 24.1%, respectively. On the other hand, the irradiation exposure time of 6 hours can deteriorate the mechanical properties; it is identified that the stress and strain are decreased to 19.42 MPa and 6.6%, respectively.