Gamma radiation effect of polymethylvinylphenylsiloxane rubbers under different temperatures

The gamma radiation effect on polymethylvinylphenylsiloxane (PMVPS) rubbers is investigated by irradiation exposure of PMVPS rubbers to a maximum dose of 200 kGy in the temperature range 28-110 degrees C. Compared with unirradiated PMVPS rubber, the elongation at break of irradiated PMVPS rubber decreases while its elastic modulus increases with the increase of absorbed dose or radiation temperature. DSC, ATR-FTIR, XPS, and H-1-NMR indicate that slight degradation and oxidation reaction occur during the irradiation of PMVPS. Solvent swelling and gel fraction study confirms that the crosslinking density of PMVPS rubbers increases gradually with increasing absorbed dose or radiation temperature. Therefore, radiation-induced crosslinking of PMVPS is dominant reactions for the chosen dose or temperature range. Furthermore, synergistic effect exists in the high-temperature radiation process for PMVPS rubbers. (C) 2017 Wiley Periodicals, Inc.