Permanently antimicrobial waterborne coatings based on the dual role of modified poly(styrene-co-maleic anhydride)

Poly(styrene-alt-maleic anhydride) was successfully (partially) modified with N,N-dimethylaminopropylamine to yield the corresponding N-substituted maleimide with dangling tertiary amine functionality. The remaining maleic anhydride units were ammonolyzed to create a water-soluble polymer. This polymer was used as a polymeric surfactant in the emulsion copolymerization of styrene and n-butyl acrylate. The tertiary amine-functional polymer was further shown to possess antibacterial and antifungal properties. When post-added to a poly(styrene-co-butyl acrylate) latex, the antimicrobial activity was not homogeneously present on a coating film made from the latex. However, when the tertiary amine-functional polymer was used as surfactant in the preparation of the latex, the antimicrobial activity was homogeneous and consistent over the entire coating surface.