Colloidal stability of styrene-acrylic latexes using anionic and nonionic polymerizable surfactants by seeded emulsion polymerization for waterborne paints

This work summarizes strategies to enhance the colloidal stability of styrene-acrylic latexes under industrial-relevant operating conditions, using anionic alkenyl ether phosphate (Maxemul (TM) 6106) and nonionic alkenyl ethoxylated polymerizable surfactants (Maxemul (TM) 5010) for waterborne paints. The influence of polymerizable surfactants mixed with conventional anionic surfactant and semi-batch seeded emulsion polymerization on the colloidal stability, particle size, zeta potential, electrolyte stability, water absorption of the polymer films, wet scrub resistance, and water absorption of the paint films were investigated. The contribution of semi-batch seeded operating conditions on the colloidal stability of poly(St/BA/AA/AM) latexes and on the waterborne paints was studied. The results showed a significant improvement in the latex stability against coagulation and end-use properties when compared to unseeded latex. The use of semi-batch seeded emulsion polymerization enhanced the application properties of the latex and paints based on the polymerizable surfactant mixtures. When polymerizable surfactant was used together with conventional anionic surfactant in semi-batch seeded conditions, stable latexes, particle sizes ranging from 105 to 130 nm, and better scrub resistance of the paint films were obtained. The use of polymerizable surfactants helps to reduce the total amount of surfactant in the latex recipe. Furthermore, the use of semi-batch seeded conditions helps in the control of particle size, coagulum content, electrolyte stability of the latexes, and increased wet scrub resistance of the paint films. The use of a seed latex prepared in situ provides additional insights for the production of poly(St/BA/AA/AM) latexes characterized by an increase in both colloidal stability and wet scrub resistance of the paint films.