Study On The Mixture Of Silica And Polystyrene-butadiene In Emulsion Polymerization With In-situ Method

ESBR is one of the most widely used synthetic rubber at present, mainly applied to produce industrial rubber goods such as tyre, rubber tube and auto parts. As a kind of amorphous polymers with relatively small intermolecular force, ESBR needs a certain quantity of fortifier while being used, traditionally carbon black or silica. However, carbon black may increase rolling resistance of tyre while fortifying, which leads to huge energy consumption. By contrast, silica as a new kind of fortifier, gives tyre smaller rolling resistance and stronger wet grap ability. Meanwhile, silica can improve the tearing resistance and scratch resistance of rubber, and prevent it from spending jumped block. People wish to take full advantage of silica for environmental and legal reasons.In modern industrial manufacturing, people scatter silica into rubber by mechanical blending. This approach often leads to auto-agglutination, caused by the uneven disperse, as well as dust pollution. In this paper, The method of in situ emulsion polymerization is used in the preparation of Silica-SBR. Research indicates that, problems of uneven disperse and silica dust pollution in post processing can be solved by taking this approach.Before preparation of rubber, surface of white silica is modified with Cationic surface active agent 1831. After that, modified silica is characterized by means of DBP absorption value analysis, infrared analysis, thermogravimetic analysis as well as TEM. It turned out that 1831 can increases lipophilicity of silica by improving its surface polarity.Therewith, modified silica and monomer is added into reactor to prepare Silica-SBR. Silica emulsifying experiment, stability and control experiment of conversion rate, contrast experiment between in situ emulsion polymerization and mechanical blending are carried out. A certain conversion rate of SBR is prepared,whose microscopic quantitative and molecular weight are analyzed soon afterwards. Dispersity and dynamic mechanical property are respectively analyzed in both method of in situ emulsion as well as mechanical blending, and compared. Conclusion of experiments are as follows:emulsion dispersion of silica can be realized by reducing its aggregation degree, quantity of silica has no significant effect in micro structure and glass transition temperature of rubber, Silica-SBR prepared by in situ emulsion polymerization has higher silica dispersity more than mechanical blending.