Optimization of process condition of silica white modified by coupling agents

In order to improve the surface hydrophobicity of inorganic material, silica white was modified by the silane coupling agent KH-550, KH-560, KH-570 and ester titanate coupling agent. Based on single factor experiment, the effect of proportion of titanate, temperature and mixing time on the surface modification of silica white was analysed by orthogonal experiment. The results showed that ester titanate coupling agent had the best result of modification. When the concentration of titanate was 60%, modification temperature was 100℃and the mixing time was 45min, activation index should increases to 99.75% and oil absorption value should decrease to 196.0mL/100g. Results of canning electron microscopy (SEM) showed that ester titanate coupling agent could decrease the aggregation of the silica white. Silica white particles were successfully modified with its organic functional groups on the surface, the hydrophobic property and the dispersion in organic solvent of silica white were improved. The results of organic modification was well.