Polyvinyl alcohol content in commercial vinyl-acrylic latexes

摘要

A significant quantity of polyvinyl alcohol (PVOH) in commercial vinyl-acrylic latexes was observed while establishing a HNMR method for compositional determination of vinyl acetate/butyl acrylate latex copolymers. A range of vinyl-acrylic latexes was examined to determine the average level of PVOH in commercial vinyl-acrylic latex copolymers as a function of vinyl-acrylic polymer type including vinyl acetate/butyl acrylates, ethylene/vinyl acetates, and vinyl-acrylic/branched vinyl ester copolymers. The PVOH level is provided in terms of the percent hydrolyzed polyvinyl acetate on a molar and weight basis, and the total weight percent PVOH based on compositional determination from ~1HNMR. The PVOH content accounts for T_g deviation from the theoretical T_g predicted from the feed monomer composition. The high levels of PVOH also provides an explanation for the well-known inferior performance characteristics of vinyl-acrylic latexes and offers an opportunity to significantly improve conventional vinyl-acrylic latex coatings.