室温硫化硅橡胶的制备及阻燃性能

In order to improve the mechanical and flame retardant properties of room-temperature vulcanized silicone rubber, flame-retardant silicone rubber composites were prepared by kneading, smelting and vulcanization processes with epoxy modified silicone rubber as matrix and reinforcing fillers, reinforcing fibers, flame retardants, ceramic fillers and other additives as fillers. The effects of four flame retardants, namely aluminum diethyl phosphinate (ADP), ammonium polyphosphate (APP), aluminum hypophosphite (AHP) and antimony trioxide (Sb₂O3), on the mechanics and flame retardant properties of silicone rubber composites were investigated by changing the type of flame retardants on the basis of fixed fumed silica, aramid fiber and boron-phenolic resin. The results show that when 25 phr of Sb2O3 were added, the tensile strength of the silicone rubber composites reaches 6.70 MPa, the initial decomposition temperature (T5%) is 350.9 ℃, and the carbon residue rate (W800℃) at 800 ℃ is 34.2%. The maximum peak heat release rate (pHRR) of the flame retardant silicone rubber composites is reduced to 228 kW/m², the maximum peak smoke release rate (pSPR) is 0.126 m²/s, and the residual mass after combustion is as high as 54.2%. In addition, the morphology of the carbon residue is relatively dense, indicating that the flame retardant has a good flame retardant effect in the condensed phase.