Emulsion Polymerization of Vinyl Acetate by a Semicontinuous Polymerization Technique and Its Applications in Latex Paints

The semicontinuous emulsion polymerization of vinyl acetate in the presence of potassium persulfate and Octyl aldehyde sodium bisulfite (OASBS) as a newly developed redox initiation system was studied using polyvinyl alcohol (PVA) as a unique surface active agent. The maximum conversion, conversion percentage per hour, stability, pH, and particle size distribution were investigated. Also, the physical and mechanical properties of latex films such as hardness, impact resistance, ductility, adhesion, and durability were studied as a function of PVA concentration. It was shown that very small amounts of PVA (0.5-1%) in the presence of the newly developed (OASBS) led to the formation of highly stable emulsions, with 40% solid content. The more stable emulsions in the previous series were chosen and incorporated in latex paint formulae for studying their physical and mechanical properties.