Grafting of styrene and 2-vinylnaphthalene onto silicone rubber to improve radiation resistance

Styrene (St) and vinyl naphthalene (2VN) were grafted onto silicone rubber (SR) as "antirads" agents for internal radiation protection. The styrene grafted onto silicone rubber (SR-g-St) sheets were synthesized by the direct gamma radiation method in hexane/ethyl acetate solutions of styrene, and SR-g-2VN in tetrahydrofuran (THF) solutions of 2-vinylnaphtalene at room temperature. The grafting reaction was carried out at doses of 10–100 kGy, at a dose rate of 8.36 kGy h−1. The resistance to irradiation of modified silicone rubber was tested at doses from 100 to 1000 kGy at a dose rate of 8.36 kGy/h. After irradiation of the un-grafted and grafted silicone materials, the crosslinking density, the average molecular weight between crosslinks (Mc), elastic modulus, and thermal properties were studied. The results show that 2-vinylnaphthalene has better radiation protection than styrene, with a protection coefficient of 0.83 compared with 0.80 for styrene. The changes in the properties of silicone rubber due to radiation were examined by infrared (FTIR-ATR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and various mechanical properties.