Use of synthetic branched carboxylic soaps in the emulsion copolymerisation of styrene and butadiene

Abstract

Abstract Sodium soaps of highly branched saturated monocarboxylic acids, in particular those containing 15–20 carbon atoms, are valuable substitutes for both rosin acid soaps and sodium stearate in cold emulsion polymerisation SBR recipes such as ASTM types 1500, 1502, and 1509. Indications are that they possess various process advantages over the normal types of emulsifier. At comparable concentrations they give higher rates of polymerisation than do the commercially available rosin acid emulsifiers and their solutions do not gel at temperatures between 5° and 20°, as is the case with sodium stearate. Moreover, they show a relatively good tolerance towards hard water. Potassium, ammonium and lithium salts of these synthetic acids are also excellent emulsifiers for the preparation of SBR latices.