Radiation effects on styrene–butadiene–styrene copolymer

Styrene–butadiene–styrene copolymer (SBS) of different configuration and block ratio were irradiated by 60Co γ-rays at 20 °C and 120 °C. The gel fraction and thermal properties before and after irradiation were discussed. The gel fraction increased with both absorbed doses and temperature. This means higher crosslinking efficiency was obtained at higher temperature. The radiation chemical yields were calculated according to the Charlesby–Pinner equation. The DSC analysis indicated that the crosslinking had taken place in the polybutadiene (PB) block while the chain scission of polystyrene (PS) block was dominant when irradiated at elevated temperature.