Synthesis of poly(vinyl acetate-acrylic acid) and its application in emulsion polymerization

The poly(vinyl acetate-acrylic acid) P(VAc/AA) emulsion was synthesized with hydrophilic acrylic acid and lipophilic vinyl acetate by the soap-free emulsion polymerization.The effect of the charging method and the ratio of monomer on emulsion stability was studied,the resulted showed that using multi-stage emulsion polymerization the polymerization stability and storage stability were better when the mass ratio of vinyl acetate and acrylic acid was (0.5-2.5)∶1;the higher pH value was in the emulsifier,the better storage stability was in room temperature.P(VAc/AA)emulsion with hydrophilic carboxyl groups from acrylic acid and lipophilic vinyl acetate chain units from vinyl acetate was a the polymeric emulsifier,which was used in vinyl acetate emulsion polymerization.The results indicated that,in comparison with the conditional OP-10/SDS emulsifier system,when using P(VAc-AA) as the emulsifer the dilution stability of emulsion was enhanced,the water absorption of film,the particle size and the viscosity decrease,and the compress shear strength reduced.