Gamma irradiation of polypropylene fibers in the presence of carbon tetrachloride

摘要

AbstractPolypropylene (PP) fibers have been irradiated with60Co γ rays in the presence of carbon tetrachloride, in the absence of oxygen. Irradiations have been carried out between dose rates of 0.078 and 0.664 Mrad/hr, and the effects of absorbed dose and temperature on the CCl formation in the PP fibers have been investigated.G(CCl) values were higher at lower dose rate.G(HCl) values were found to be much higher than theG(CCl) values, and IR absorption studied indicated increasing unsaturation with increasing dose. The number average molecular weights (M̄n) were evaluated from intrinsic viscosity measurements in decalin at 408 K and theM̄nvalues decreased with increasing dose and temperature.G(scission) −G(crosslinking) values were calculated and it was found that theGs−Gxvalues are higher at lower doses and higher dose rates. The thermal characteristics of the irradiated fibers were investigated by thermogravimetry (TG) analysis in air or argon and with differential scanning calorimetric (DSC) studies. The TG data indicated slightly less thermal stability for the modified fibers both in air as well as argon. The DSC data indicated very little change in the melting points of the samples, the melting points being arou