Interaction between styrene–ethylene oxide block copolymers and sodium lauryl sulfate in aqueous solution

Abstract

AbstractInteractions of water‐soluble AB block copolymers of polystyrene and poly(ethylene oxide) with sodium lauryl sulfate (SLS) in aqueous solution were investigated by high‐resolution proton magnetic resonance (NMR). The viscosity in aqueous SLS solution was also measured. From the NMR results in D2O, it appears that molecular motions of the polystyrene blocks of the copolymer in aqueous solution are activated by interaction between the polystyrene blocks and the added SLS. From solution viscosity, on the other hand, it is apparent that a complex is formed between the copolymer and SLS and that it exhibits typical polyelectrolyte properties. The polyelectrolyte character is attributable largely to intrachain repulsions between like charges of the SLS anions adsorbed on the poly(ethylene oxide) blocks of the copolymers since the polystyrene blocks are insoluble in water and the styrene content is less than 10%.