A comparative study of the effect of gamma and electron beam irradiation on the optical and structural properties of polyurethane

Abstract

The effects of both gamma and electron beam irradiation on the color changes of polyurethane were investigated. Samples from polyurethane were classified into two groups. The first group was exposed to gamma doses at levels between 20 and 200 kGy. The second group was exposed to an electron beam with similar doses. The transmission of these samples in the wavelength range 370–780 nm, as well as any color changes, was studied. The Commission International de E'Claire (CIE units X, Y and Z) methodology is used in this work for the description of the colored samples. Additionally, the color differences between the non-irradiated sample and those irradiated with different gamma or electron beam doses were calculated. The results indicate that the polyurethane polymer acquires color changes under gamma or electron beam irradiation, but the response of polyurethane to color changes by electron beam irradiation is higher than the response to gamma irradiation. The structural modifications in the gamma and electron beam-irradiated polyurethane samples have also been studied as a function of the dose using the refractive index and Fourier transform infrared (FTIR) spectroscopy.