Effect Of Functional Fillers On The Properties Of High Temperature Vulcanized Silicone Rubber

In this paper,the effects of reinforced filler silica aerogel,hydrophobic fumed silica,hydrophobic precipitated silica and three functionally modified fillers graphene,molybdenum disulfide and tungsten disulfide on the properties of high temperature vulcanized silicone rubber(HTV)were studied.Explored the relationship between the microstructure and dosage of inorganic fillers and the physical and mechanical properties,static and dynamic mechanical properties,wear resistance and thermal properties of high-temperature vulcanized silicone rubber,and analyzed from DMA,SEM,AFM and FTIR,etc.From the micro and macro perspectives,study the interaction mechanism between high-temperature vulcanized silicone rubber and different inorganic fillers to prepare functional high-temperature vulcanized silicone rubber materials.The addition of three hydrophobic silica nanoparticles can effectively improve the mechanical properties of HTV,among which aerogel reinforced silicone rubber composites have the best performance.The tensile strength of aerogel vulcanizate was increased from0.28 MPa to 9.52 MPa,and the elongation was increased from 78% to 750%.The addition of aerogel improved the tensile strength and elongation at break of silicone rubber and showed excellent elastomer properties.At the same time,the modified aerogel silicone rubber composite has higher tear strength(33.98 k N/m),high hydrophobic contact angle(124°),high hardness(70 HA),and low wear rate(0.04 g/cm2),low thermal conductivity(0.11W·m-1·K-1).The dynamic thermomechanical analysis(DMA)test results show that the Tg of the blended vulcanizates are negative,the blended vulcanizates have excellent low temperature performance.On the basis of aerogel reinforced silicone rubber,the effects of functional graphene-like materials molybdenum disulfide and tungsten disulfide on the properties of high-temperature vulcanized silicone rubber were further studied and compared with the effects of graphene materials.The study found,graphene has no significant effect on the performance of silicone rubber,and has an enhanced effect on the hardness of silicone rubber,with a maximum hardness of 81 HA.The elongation at break of molybdenum disulfide silicone rubber increased from 640% to 1041%,and the tear strength was up to 36.3k N/m.Tungsten disulfide significantly reduces the tensile strength,shore hardness and impact resilience of silicone rubber composites.When the added amounts of molybdenum disulfideand tungsten disulfide are both 4 wt%,the cross-linking degree of the tungsten disulfide silicon rubber composite is 74.8%,which is significantly lower than that of the molybdenum disulfide silicon rubber composite 92.9%.