Gamma-ray induced polymerization of styrene in the presence of methanol

The kinetics and molecular weight distributions (MWD) of the gamma-ray induced polymerization of styrene in methanol were studied at 35°C, at low conversions and over a dose rate range of 2.76 × 10³ to 2.74 × 10⁴ rad/hr. The data obtained at low initial methanol content agreed with previously obtained results and the MWD of the polystyrene formed yielded a single unimodal peak with M?_n in the range of 35,000–480,000. However, at high initial methanol content and low dose rates, at least three peaks were clearly discernible over wide molecular weight distributions. The existence of these peaks is related to the kinetic data and the formation of three distinguishable regions in the polymerization system.