Admicellar polymerization in a continuous stirred tank reactor : effects of nonionic surfactant

Abstract

In order to reduce the production cost of the modified silica, mixed surfactants of cationic and nonionic surfactants, cetyltrimethyl ammonium bromide (CTAB) and Triton X-100, were employed in the admicellar polymerization to replace the use of CTAB alone. In this study, the effect of the molar ratio of CTAB to Triton X-100 and the adsorption structure of surfactants, monolayer and bilayer, were investigated on the admicellar polymerization compared with the polymerization using only CTAB in terms of the compatibility between rubber and silica. The results indicated tha the improvement in the overall properties of rubber compound was achieved with 3:1 and 1:3 CTAB/Triton X-100 molar ratios when compared to the case with only CTAB. Interestingly, the modified silica with the monolayer adsorption structure of the mixed surfactants at all molar ratios gave better overall properties of rubber compound than those with the bilayer structure.