Kinetics of the Acid-Catalysed Hydrolysis of Vinyl Acetate in the Presence of Anionic Surfactants

Abstract

Vinyl acetate (VAc) is one of the most frequently investigated and widely used monomers. Multitonnage production of different (co)polymers in the form of lacquers, dispersions, and “beads” of various grades of polyvinyl alcohol and polyvinyl acetals has been based on VAc [1]. The use of new initiating systems and other components of the reaction system can make it possible to improve or even change considerably the service properties of polymers based on vinyl acetate and, thus, to expand the area of their application. The present investigation involved the production of high molecular weight polyvinyl acetate by emulsion polymerisation of vinyl acetate in the presence of initiating systems based on chelate complexes of manganese. The application of the given systems is effective at pH ≤ 4 and therefore presupposes the use of acidic agents. Under the given conditions, vinyl acetate, as an ester, will undergo hydrolysis with the formation of acetaldehyde and acetic acid, which have a negative effect both on the polymerisation process and on the quality of the polymer obtained [2–4]. Therefore, it is of interest to investigate the process of hydrolysis of vinyl acetate in an aqueous medium with real working concentrations of the principal components of the polymerisation system with the aim of determining the possibility of reducing the effect of hydrolysis products. An investigation was made of the influence on hydrolysis of sulphuric and acetic acids in the presence of ionogenic emulsifiers.