Copolymerization of styrene and reactive surfactants in a microemulsion: control of copolymer composition by addition of nonreactive surfactant

The gamma-ray-induced copolymerization of styrene and the surfactant monomer (surfmer) (11-acryloyloxy)undecyltrimethylammonium bromide, 1, - with and without the presence of the nonreactive surfactant N-dodecyltrimethyammonium bromide, 2, - was studied in a single-phase (1 Phi) oil-in-water microemulsion. Upon exchange of 50 weight percent of 1 against 2 the 1 Phi region could be increased to higher styrene content. Upon gamma-ray irradiation a copolymer is formed: this copolymer exhibits a larger styrene-to-surfmer ratio than the original monomer mixture. This allowed the styrene-to-surfmer molar ratio in the resulting polymer to be varied from 0:1 to 4.3:1. The larger styrene-to-surfmer ratio originates from the simultaneous formation of homopolymer P-l, which is in accordance with the Candau-Leong-Fitch model of polymerization. Further information on particle size and material properties of the copolymers, which is not accessible by other preparation methods, is also given.