ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Influence of the type of activator and emulsifier on heterogeneously initiated polymerization of styrene

V. Chrástová, P. Citovický, D. Mikulášová, and J. Schenkmayer

Department of Chemical Technology of Plastics and Fibres, Slovak Technical University, CS-812 37 Bratislava

Abstract: In the emulsion polymerization of styrene initiated by hydrogen peroxide of the oxidized isotactic polypropylene at 30 °C the influence of the activator FeS0₄ —disodium salt of ethylenediaminetetraacetic acid (EDTA) and of the ionic (Mersol H) as well as nonionic (Slovasol 2430) type of emulsifier on the course of polymerization was investigated. The method of planned experiment was used for determining the optimum concentration of activator (c_em = 0.89 x 10^-3 mol dm^{- 3} ) and Slovasol 2430 (c_em = 7.4x 10^-2 mol dm^{- 3} ) in emulsion. For these concentrations the 90.7 % degree of conversion of styrene was obtained after 60 min polymerization. Provided the combination of the FeS0₄ —EDTA activator with Mersol H was used, an increase in activator concentration had negative effect on the rate of styrene polymerization, which might be due to rapid consumption of available peroxides. It has been found that FeS0₄—EDTA also affects the pH value of medium because of acidification of the metallic component. Owing to its basic character, the nonionic emulsifier Slovasol 2430 is capable, to a certain extent, to restrain this influence of activator, which has not been observed with the ionic emulsifier Mersol H.

Full paper in Portable Document Format: 404a499.pdf

Chemical Papers 40 (4) 499–507 (1986)