Study On The Preparation Of Nano Silica And Its Application In Styrene-Butadiene Rubber

As the "green tire" is developing very fast, the maket of silica which used in tire was very big. The precipitated silica was prepared using sodium silicate and sulfuric acid as raw materials and generally had a lot of hydroxy, unsaturated bond, and adsorbed water. When the silica was used in the SBR, Its dispersibility in SBR was low, the corroborative ness of SBR was low too. To improve the process to produce highly disperse silica had been activity.In this paper, the influence of the concentration of sodium silicate, reaction time, the temperature of the reaction, the volume of ethanol,the time to add ethanol, drying method on the BET surface and DBP absorption value of silica were investigated. The structure of silica was investigated using TEM during the reaction in order to find the most important step of process. The results show that:The optimum conditions of preparing SiO2were at which the concentration of sulfuric acid was2.40mol/L, the concentration of SiO2was7.5%, the concentration of alcohol was1.26%, the temperature was80℃, the stiring peed was700rpm and final pH value was5.5-6.The influence of concentration of hydroxyl carboxylic acid on the BET surface and DBP absorption value of silica were investigated. The highly disperse silica was produced at the concentration25%of lactic acid and100%of citric acid respectively.The silica produced was applied to make ruber processing. Its dispersibility in SBR was improved, the DBP absorption value was higher, and the mechanical property of SBR was better.