Light decomposition characteristics of UV-irradiated polycarbonate

In this paper, the polycarbonate (PC) materials were aged using a monochromatic light source of wavelength 185 nm using a model UV-O₃ Clear for a study of light decomposition. The Fourier Transform infrared spectroscopy (FTIR) results showed that intensities of the peak bands corresponding to C=O, C-O, -O-CH- at 1690 cm^-1, 1160-1254cm^-1, 1050cm^-1, decreased with the increase of the aging time, respectively. But the isopropyl at 1380cm^-1 didn't show obvious change. In addition, it was found that after the aging test, the thermal decomposition temperatures of the PC samples increased by 21%. Moreover, UV-Visible absorption spectroscopy showed that a band at 290 nm could be contributed to increase of phenolic OH content during aging. Transmittance spectroscopy revealed that the transmittance of the samples decreased with the aging time. And there were not significant changes in the transmittance due to the aging when the samples were exposed to UV radiation for 3 hours above 500 nm.