Electrostatically and sterically stabilized microemulsion polymerization of styrene in the presence of macroinimer

Abstract

Oil-in-water microemulsion polymerizations of styrene initiated by ammonium peroxodisulfate (APS) and sodium thiosulfate (STS) redox system with and without the macromonomeric azoinitiator [4,4′-azobis-valeronitrile(4-vinylbenzyl(poly(ethylene glycol)ether), macroinimer or MIM] were investigated. The microemulsion polymerizations were performed with either sodium dodecyl sulfate (SDS) or the nonionic Tween 20 as stabilizer. The polymerization kinetics is characterized by two non-stationary rate intervals determined from conversion– time curves. This behavior is the result of continuous particle nucleation during the entire reaction. The macroinimer favors additional particle nucleation and thus influences the kinetics of microemulsion polymerization considerably. The rate of polymerization is strongly influenced by the choice of the stabilizer where the nonionic Tween 20 causes much higher rates than the anionic SDS.

Acknowledgements This project was supported by TUBITAK-NATO-B1. The first author acknowledges TUBITAK (Scientific and Technical Research Council of Turkey), for the award of a research fellowship and Klaus Tauer for helpful discussions as well as all co-workers of the Department of Polymerization Reaction at the Polymer Institute (Slovak Academy of Sciences, Bratislava, Slovakia). One of the authors appreciates the support by VEGA through the grant number 2/1014/21.