Amphiphilic copolymers of styrene with a surfactant-like comonomer: gel formation in aqueous solution

We report on the synthesis and the properties of a novel water soluble poly mer based on two comonomers, one hydrophobic and one amphiphilic: styrene a nd dimethylhexadecyl(vinylbenzyl)ammonium chloride, respectively. The behav ior of aqueous solutions of the copolymer has been studied by rheology and compared with the properties of its polyelectrolyte and polysoap homologues . At concentration as low as 2% (w/w), they exhibit gel characteristics des pite the low degree of polymerization of the copolymer chains (DPn congruen t to 70). By analogy to surfactants, this suggests the formation of elongat ed aggregates involving several polymer chains. The birefringence shown by the solutions is a way to probe the formation of these superstructures insi de the solution. (C) 2000 Elsevier Science B.V. All rights reserved.