Polymerization of vinyl acetate in microemulsions stabilized with a mixture of dodecyltrimethylammonium bromide and didodecyldimethylammonium bromide

Polymerization of vinyl acetate (VA) in three component oil/water (o/w) mic roemulsions stabilized with a mixture of two cationic surfactants (DTAB/DDA B in a weight ratio of 3), was carried out at 40, 50 and 60 degrees C using a water soluble initiator, V-50. In all cases studied, stable latexes cont aining particles with diameters between 70 and 110 nm were obtained. Partic le size increased with conversion yielding uncommonly large particles for m icroemulsion polymerization, probably because particle coagulation. Multimo dal molar mass distributions with average molar masses between 1.2 to 2.0x1 0(6) g/mol were obtained. Chain transfer to polymer and bimolecular termina tion reactions play important roles in the microemulsion polymerization of this monomer.