Preparation and properties of filler modified low viscosity and high-temperature resistance silicone rubber adhesive
In response to the performance and process requirements of silicone rubber adhesive in high-temperature ablation environments,a low viscosity phenyl silicone rubber base adhesive was synthesized,and the molecular weight distribution,phenyl content,and viscosity of base adhesive were characterized.The prepared base adhesive had a phenyl content of 22.5%to 23.8%,a viscosity of 6 530 to 11 500 mPa·s,and a volatile content of 0.30%to 0.37%.This indicated that both the viscosity and volatile content of base adhesive were at a low level,which was conducive to good processability.Subsequently,the room temperature vulcanizing silicone rubber adhesive was prepared by mixing phenyl silicone rubber base adhesive with white carbon black,iron oxide red,and chopped carbon fiber.A three-factor,three-level orthogonal experiment was used to investigate the effects of inorganic fillers on the viscosity,tensile shear strength,and temperature resistance of silicone rubber adhesive.The research results showed that,(1)From the range analysis of viscosity and tensile shear strength,it could be seen that white carbon black had the greatest impact on viscosity,followed by chopped carbon fiber.Adding white carbon black would increase both tensile shear strength and viscosity.Therefore,within the allowable range of viscosity,increasing the amount of white carbon black could improve tensile shear strength.(2)The range analysis of residual carbon rate showed that iron oxide red had a much greater impact on residual carbon rate than white carbon black and chopped carbon fiber.Iron oxide red could significantly improve the thermal stability of silicone rubber adhesive.When the amount of iron oxide red added was 10 parts,the swelling and exhaust during the heating process were significantly suppressed.
万方数据
维普
