Study On Preparation And Application Of Crosslinked Silicone Rubber Powder

Silicone rubber powder is a kind of spherical organic silicon powder with a particle size from 0.1 to 100 μ m. Silicone rubber powder can exhibit the general performance of silicone rubber and also show many special functions in the synthesis process by controlling the particle size, introducing characteristic groups, crosslinking density, or grafting with a variety of functional materials.In this paper, the silicone rubber powder with different properties is synthesized by using different crosslinkers and catalysts. Furthermore, the silicon rubber powder microspheres are also prepared by the modification to silicone rubber powder emulsion.As a result, better dispersion of silicon rubber powder in the GPPS resin is obtained while the transmittance, haze and mechanical properties of GPPS resin are also improved..It can control the silicon rubber powder particle size through controlling the phase inversion process. The results show that the amount of water and adding method in the phase inversion process have a great effect on the latex particle size. The particle size of silicone rubber powder emulsified by using particle size analyzer and the result shows a range of 0.2~15 μ m. The result of thermal analysis shows that the decomposition temperature of silicon rubber microspheres is 480℃ which indicates that the silicone rubber powder exhibits excellent heat resistance. The high heat resistance property ensures that the structure of silicone rubber powder microspheres structure will not be destroyed when blended into the resin. The scanning electron microscope result indicate that the silicone rubber shows smooth surface and spherical shape with little defect. Stereo microscope shows that the silicone rubber powder microsphere is a kind of transparent organic silicon sphere. The effect of silicone rubber powder content and particle size on the resin’s light transmittance / haze is tested by dispersing the silicon rubber powder microspheres with different particle size into GPPS resin. When the particle size is smaller and the content is higher of silicon rubber powder, the resin exhibit lower light transmittance and higher haze. When the silicone rubber powder in the GPPS resin is contented 0.3%, the rubber powder size increases from 0.17μm to 8.1μm, the transmittance increases from 65.1% to 87.8%,haze decreased from 94.2haza to 55.5haza.The effect of silicon rubber powder on the mechanical properties of GPPS resin is investigated. When the elastomer microspheres are added into the GPPS resin, the tensile strength and elongation at break of the resin are increased, and the impact strength is also improved. When the content of GPPS resin was 0.1%, the tensile strength increased 33%, and the elongation at break was increased by 800%.The silicone rubber powder prepared by hydrochloric acid catalysis method through the TAG thermal analysis shows a good heat resisitance of the silicone rubber microspheres and the decomposition temperature is 513℃. The transmission electron microscopy analysis shows good dispersion in GPPS resin of the silicone rubber powder which keeps spherical shape well. The transmittance and haze of GPPS resin can be significantly modified by silicon rubber powder. When the silicon rubber powder content was 0.2%, the haze reached 92.3haza and the transmission rate can be maintained at 72.3%. The mechanical properties of GPPS resin can be obviously improved by the adding of silicone rubber powder: with the increase of the silicone rubber powder content, the elongation at break and impact strength of GPPS resin are improved obviously.Through the experiments by using different crosslinking agents and modified by styrene, we find that: when KH570 and methyl trimethoxy silane are used as cross-linking agent, the silicone rubber powder exhibits large particle size when modified by styrene,it can be 0.46μm and 0.72μm.The effect of different silicon rubber powder on the transmittance and haze of GPPS resin is studied. We find that the modified silicone rubber powder by styrene show higher transmittance and haze.Transmittance/haze is 78.8/90.5,when the silicon rubber modified by the styrene and transmittance/haze is 81.9/76.5,when the silicon rubber is unmodified.The study on the effects of different silicon rubber powder on the mechanical properties of GPPS resin shows that the use of modified silicon rubber powder by styrene in GPPS resin can significantly help to improve responding mechanical properties, and the improvement on the GPPS elongation at break and beam impact strength is most obvious.The elongation at break increased by 1100%, and the impact strength increased by 560%.