INTERACTIONS IN SOLUTION BETWEEN A HYDROPHOBIC POLYMER AND VARIOUS KINDS OF SURFACTANTS

Interactions in solution between a hydrophobic polymer and surfactants were studied by viscometry, light scattering and conductimetry measurements. One polymer, poly(2-ethyl hexyl methacrylate) (P2EHMA), five surfactants, sodium dodecyl sulfate (SDS), hexadecyl trimethylammonium bromide (HTAB), hexadecyl pyridinium chloride (HPCl), and ethoxylated nonyl phenol containing 10 or 25 segments of ethylene oxide (NP10 or NP25), and one solvent mixture, THF/6 vol% H2O were used in this work. For the P2EHMA/surfactant mixtures in THF/6 vol% H2O, the viscosity versus surfactant concentration curves are similar in shape for all surfactants. They show a minimum at low surfactant concentration followed at higher concentration by a maximum and a plateau. An interpretation of these curve shapes is proposed. The relevance of these findings to the problem of the polymer/surfactant interactions in latexes and latex films is also discussed.