Study On Preparation And Properties Of Fluorine-containing Gradient RTV Contamination Flashover Resistance Coating

RTV coating has favorable hydrophobicity, recovery of hydrophobicity and transfer of hydrophobicity, owns good anti-contamination flashover properties; it has a relative long lifetime, and is easy to be cleaned; besides, it is available to every kinds of running environment. So, RTV coating has been used in the electric field extensively, being coated on insulator to resist contamination flashover. The RTV contamination flashover resistance coating used nowadays has the following defects:the mechanic properties of RTV is poor, and that cause the destroy of it when the weather is stormy; flame resistance property is bad, so the occurrence of arcs on the surface of the coating may lead to combustion, which will damage the electric power facilities; Hydrophobicity, recovery and transfer of it should be improved. All the problems above are the key points of RTV contamination flashover resistance coating.The influence of four kinds of fillers to the mechanic of RTV silicone rubber was investigated. Firstly, the reinforcement effect of two kinds of fumed silica with different particle size was studied, then, we compared the reinforcement effect of nano-MDH and micro-ATH, and find out that nano-MDH has a better reinforcement effect in this situation, besides, they both has a synergistic reinforcement effect. The influences of component flame retarders to mechanic and flame resistance properties were investigated.In order to improve the hydrophobicity, recovery and transfer of it, HFSR, a component with lower surface energy, was added to obtain gradient films with HFSR enriching on the surfaces of air-film. We investigated the influences of category of solvents and substrates, the amounts of curing agent and fillers to the structures of self-stratifying coatings:the solvent systems of toluene/petroleum ether and cyclohexanone/petroleum ether can promote the HFSR to move towards to the surface of the coating; substrates with different surface energy have significant impact to the movement of HFSR; besides, the increasing of the amounts of curing agent and fillers will reduce the enrichment of HFSR on the surface.According to the results above, two kinds of fluorine-containing silicone compound were used to improve the hydrophobicity of coating, and distribution of F-109 and HFSR cross sections of coatings were measured by SEM-EDS; HFSR has the tendency to move to the surface of coatings, while the concentration of F-109 is gradient distributed cross sections of coatings. Hydrophobicity and recovery of it are improved with the increasing of fluorine-containing silicone compound. When 25% fumed silica,12% EBPDE,4% sb2o3,30%MDH,4%HFSR and 1.5%F-109 are added, the tensile and tear strength of coating are 4.41 MPa and 14.5 KN/m respectively, flame retardant rating is FV-0, the CA of water is 118.3°...