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 polymer based on two comonomers, one hydrophobic and one amphiphilic: styrene and dimethylhexadecyl(vinylbenzyl)ammonium chloride, respectively. The behavior 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 despite the low degree of polymerization of the copolymer chains (DPn congruent to 70). By analogy to surfactants, this suggests the formation of elongated aggregates involving several polymer chains. The birefringence shown by the solutions is a way to probe the formation of these superstructures inside the solution. (C) 2000 Elsevier Science B.V. All rights reserved.