A SYSTEMATIC-APPROACH TO THE STUDY OF MULTICOMPONENT POLYMERIZATION KINETICS - THE BUTYL ACRYLATE METHYL METHACRYLATE/VINYL ACETATE EXAMPLE.2. BULK (AND SOLUTION) TERPOLYMERIZATION/

A systematic study of the terpolymerization of butyl acrylate/methyl m ethacrylate/vinyl acetate (BA/MMA/VAc) is being conducted. In the seco nd stage of this study, bulk (and solution) terpolymerizations of BA/M MA/VAc were performed. The polymers produced were characterized for co nversion, composition and molecular weight. The terpolymerizations exh ibited behaviour similar to vinyl acetate-containing copolymerizations , that is, a ''double gel effect'' was observed. During the first peri od of the reaction the acrylic monomers virtually ''copolymerized'' an d thus the reaction exhibited the characteristics of a ''solution'' co polymerization of the acrylic monomers with the vinyl acetate acting a s the ''solvent''. Typical ''solution'' polymerization behaviour, i. e ., a dampened autoacceleration or gel effect, was in evidence for this first period of the reaction. After the virtual depletion of the acry lic monomers, the remaining vinyl acetate polymerized and exhibited it s own characteristic gel effect. Estimates of the copolymerization rea ctivity ratios obtained previously were found to accurately predict te rpolymer composition up to high conversion levels. Molecular weight re sults indicated that branched polymers were being produced at high con versions in the bulk experiments.