Novel reactive surfactants for latex emulsion polymerization

 
Surfactants play a key role in emulsion polymerization, emulsifying vinyl monomers and stabilizing the resulting dispersion. However, their presence in latex-based coatings can also have deleterious effects. Migration of conventional surfactants creates hydrophilic domains within the polymer matrix, leaving it vulnerable to water penetration. Reactive surfactants offer a potential solution to these issues. With the inclusion of a reactive double bond the surfactant becomes covalently bound to the polymer, preventing migration within the coating film. Stepan has developed a novel, patent pending, APE/VOC free class of reactive surfactants. Multiple product concepts were screened for a variety of properties, including leaching and wet scrub resistance. The degree of surfactant incorporation into the latex was evaluated using LCMS. These novel chemistries offer greater water resistance and adhesion, coupled with lower foaming, when compared with commercial (reactive) benchmarks.