KINETIC-STUDIES ON EMULSION COPOLYMERIZATION OF VINYL-ACETATE AND ACRYLICS IN THE BATCH PROCESS

The batch emulsion copolymerization of vinyl acetate and acrylic monom ers (acrylic acid, methyl acrylate and acrylamide) was investigated at 25 degrees C with a redox initiator system and a complex emulsifier. The kinetic behaviour of the copolymerization and the structure of the resulting copolymers, as well as the particle size and the number den sity of the latexes, were studied as a function of the conversion and the reaction time. The results show that the copolymerization process has a three-stage feature under the conditions of the optimum concentr ation of the initiator and the emulsifier being 0.2 wt% and 2.0 wt%, r espectively. During the process, the particle size and the number dens ity change drastically and finally reach limiting values of 110 nm and 2.5 x 10(14) mL(-1), respectively, for VAc-AA-AM terpolymer. A specia l mechanism of particle formation is proposed. Copyright (C) 1996 Else vier Science Ltd