Comparative Study Of Radiation Effects Of Graphene Oxide And Phenyl On Silicone Rubber

Silicone rubber is a kind of polymer material with repeated unit Si-O bond as main chain and methyl,vinyl,phenyl and other organic groups as side chain.Because of the special structure,the silicone rubber is determined with excellent high and low temperature resistance,solvent resistance,aging resistance,weather resistance,electrical insulation and other advantages,which has been widely used in nuclear industry,aerospace industry,etc.However,the irradiation of high energy rays will deteriorate the performance and affect the use of silicone rubber products.Therefore,it is of great theoretical significance and application value to improve the radiation resistance of silicone rubber.In order to improve the radiation resistance of silicone rubber with two methods of "Guard protection" and "internal protection" to start,Si O2-graphene oxide(GO)/MVQ and Si O2/MVPQ were designed and prepared.We studied the compatibility of GO and silicone rubber system and the irradiation effect of GO-SiO2/MVQ,the influence of phenyl on the irradiation effect of MVPQ.We examined the compatibility of GO and silicone rubber matrix and its dispersion in silicone rubber.The results showed that when the adding amount of GO is 2 phr,the silicone rubber synergistic reinforcement effect is the best,compared with only adding Si O2 silicone rubber.And the 100% tensile strength was increased by 37%,the tensile strength was increased by 17%,the elongation was increased by8%,the initial dynamic modulus was increased by 115%.After adding GO,the Payne and relaxation effect of the composite materials are increased,and from another point of view,GO and Si O2 form a better filler network in common.SEM showed that GO can be uniformly dispersed in the silicone rubber?In the third chapter,based on the compatibility of GO and silicone rubber matrix and its dispersion in the silicone rubber,irradiation effect of GO-SiO2/MVQ composites were studied.The tensile test showed that the mechanical properties of silicone rubber decreased significantly after the addition of GO,and the optimum dosage of GO is 2 phr.After the irradiation of 500 k Gy,the tensile strength andelongation at break of MVQ only containing Si O2 were 3.9Mpa and 96%,which were decreased by 30% and 77% compared with that before irradiation.The tensile strength and elongation at break with MVQ containing 2 phr GO were 5.1Mpa and142%,and decreased by 23% and 68%,compared with that before irradiation.It illustrates that GO can improve the irradiation resistance of MVQ obviously.This is attributed to the quenching effect of GO on the free radicals produced by irradiation,and its good gas barrier properties,can reduce the irradiation aging caused by O2.so it has good effect of radiation protection.The dynamic mechanical properties of the composites showed that the initial storage modulus of the composites increased with the add of GO after irradiation,which indicated that the crosslinking reaction induced by irradiation was dominant.After irradiation,the storage modulus of silicone rubber with 2 phr GO rarely changed,which indicated that the effect of radiation crosslinking was the least,and the radiation resistance was the best.The TGA analysis showed that the thermal stability of GO-Si O2/MVQ composites decreased in different degrees after irradiation,which was caused by the degradation of silicone rubber molecular chain affected by radiation.Without GO of MVQ weightlessness 5% of decomposition temperature reduced the most.The influence of phenyl on the irradiation effect of MVQ were investigated.The result showed that,after the radiation of 500 k Gy,the tensile strength and elongation at break of MVQ decreased 30% and 77%.And that of MVPQ with 10%diphenyl were reduced by 16% and 16%,respectively.The results of tests showed that the scale of decrease of tensile strength and elongation at break of silicone rubber decreased after irradiation.With the increase of phenyl content,the radiation resistance increased firstly and then decreased slightly.This is attributed to the large bond of benzene ring,which can disperse and absorb the radiation energy,but when the phenyl content is too high,it will hinder the vulcanization and reduce chemical reinforcement.The results of dynamic mechanical tests and relaxation experiments showed that the larger contents of phenyl groups in the silicone rubber,the hindering effect on the radiation crosslinking was more obvious.