Studies of adsorption onto synthetic latices

Despite the importance of reactions at the polymer‐water interface of synthetic latices very little work has been reported on the adsorption of surfactants or water‐soluble macromolecules at this site. In the studies reported here the adsorption isotherms of sodium lauryl sulfate onto polystyrene and poly(n‐butyl methacrylate) and of hydroxyethyl cellulose onto poly(n‐butyl methacrylate) are shown to be of the Langmuir type. Other water‐soluble macromolecules and latex substrates were studied at a single macromolecule content and a single latex solids level. The effective surface area of the sodium lauryl sulfate molecule, at the critical micelle concentration, was found to be 58.5 Å2 for both polystyrene and poly(n‐butyl methacrylate). This is in good agreement with results obtained by soap titration. The adsorption of macromolecules is strongly influenced by macromolecule type as well as by the latex substrate, i.e., the type of surfactant on the latex surface as well as the polymeric composition of the latex.