Preparing sulfur nanoparticles and determining their effect on the photodegradation of polycarbonates

This study involved the preparation of sulfur nanoparticles using the extract of Ziziphus-spina leaves and examined their effect on the photodegradation of polycarbonate membranes with a thickness of (60±5) microns, after adding various concentrations of the nano additive (0.1%, 0.05%, 0.025%, 0.0125%, 0.00625%) to a polycarbonate solution dissolved in chloroform. Sulfur nanoparticles were characterized using different techniques such as SEM, XRD, and FT-IR. A band at 460 cm-1 was identified according to FT-IR analysis, indicating the formation of sulfur nanoparticles. Photodegradation of polycarbonates, both with and without the additive, was monitored using UV-Visible analysis at a wavelength of 356 nm over varying irradiation times (0, 30, 60, 120, 180 hours), calculating the rate constant of photolytic fragmentation for the polymer additive. The results showed an increase in the photodegradation of polymer films with an increase in the concentration of the nanomaterial compared to films without the additive. Using FT-IR analysis, the carbonyl absorption coefficient was calculated and found to increase with the concentration of the added nanosulfur, consistent with the Kd values (rate constant of photolytic fragmentation). Additionally, the average molecular weight of the polymer, the degree of disintegration, and the numerical rate of polymer chain scission were calculated using a viscometer. It was observed that the average molecular weight of the polymer decreases with increasing irradiation time and the rate of chain scission increases.