An Investigation Into The Preparation And Properties Of Precipitated Silica Specially Used In Organic Silicon Rubber

The structure characters of silica (White Carbon) and silicon rubber wereintroduced completely in the present paper. Reinforcing mechanism of silica (WhiteCarbon) as reinforcing agent on silicon rubber was discussed in detail. The effect ofsurface character of precipitated silica on silicon rubber was testified by experiments.Other metallic ions and inorganic impurities can be removed efficiently by usingfabricating agent A to purify raw material water glass and using soft water to react andwash in the whole process of synthesizing silica. This solved the problem of siliconrubber becoming yellow as using native common silica as raw material and obtainedgood applying effect. Silica of different surface characters was obtained throughcontrolling the silica synthesizing technical conditions. Characteristic parameters ofsilica which suit to produce organic silica rubber were optimized by reviewing theeffects of precipitated silica surface structure characters on the reinforcing abilities ofsilicon rubber basing on surface areas, porosity volume(oil absorptions)and averageparticle-size of aggregated silica. The novel surface modifying agent (VTES) wasused to modify the precipitated silica surface, so the surface properties of silicaparticles, dispersing property of silica in silicon rubber and the reinforcing abilities ofsilica to silicon rubber were improved efficiently, especially in the tear strength. Thecontrast test of mixing rubber compounds between precipitated silica produced underthe prim technical condition and foreign products were made, the results exhibitedthat the quality of the precipitated silica product has achieved or exceeded theimported product (NIPSILLP). The reinforcing abilities and the tear strength ofprecipitated silica modified by VTES have exceeded that of fumed silica M-5 and were closedto that of foreign reelection product (R-972).