Preparation And Properties Of Heat Resistance Vulcanized Phenyl Ether Silicone Rubber

In this paper, the high temperature silicon rubber was prepared by phenyl ether silicone rubber and other ingredients. Phenyl ether silicone rubber is a special rubber which has good high temperature tolerance. The processing conditions and vulcanization characteristics were studied. The effect of heat resistant additives, silazane and sericites on the mechanical properties, heat-resistant properties and electronic properties were also involved.With benzyl ether silicone rubber, hydroxyl silicone oil, silica, dicumyl peroxide(DCP), heat-resisting additive as the basic formula, the optimum curing temperature was determined by the rubber vulcanization instrument analysis, and the curing time was determined by measuring mechanical properties of silicone rubber sample in different curing time. The result showed that the optimum curing temperature is 170℃, and the corresponding curing time is 8 min. The post cure conditions as follows: 150℃×1h, 170℃×1h, 230 ℃×4h, the physical properties of phenyl ether silicone rubber remained basically stable.The effects of ferric oxide and soluble H801 CT on mechanical properties of silicone rubber were studied. Two heat-resisting additives have a very small impact on electric properties of vulcanized rubber. The tensile strength first increased then decreased with the increase of heat-resisting additive content. The results showed that ferric oxide and soluble H801 CT could significantly improve the thermal stability of phenyl ether silicone rubber in high temperature, and the optimum dosages were 3phr and 1phr, respectively.Hexamethyl-disilazane(HMDS) could obviously affect the mechanical properties of vulcanized rubber. With HMDS content increased from 0phr to 2phr, the tensile strength increased first and then decreased, but elongation at break and hardness increased all along. HMDS also improved the electrical properties. The results indicated that the HMDS can improve the heat resistance of phenyl ether silicone rubber. When the dosage is 0.5phr, the retention tensile strength and elongation at break were 84% and 91.2% respectively through 0.5 hours of ageing at 350 degrees.Replacing part of silica with sericite can make processing easy, but the sericite have a negative effect on mechanical properties of the vulcanizates. With the increase of sericite content, the tensile strength of vulcanizate decreased. The adhesion of sericite to silicone rubber was weaker than silica by scanning electron microscope. Sericite also can help improve the heat resistance of phenyl ether silicone rubber, its dosage is bigger, the better the results.