POLY(SULFOBETAINE)S AND CORRESPONDING CATIONIC POLYMERS .3. SYNTHESISAND DILUTE AQUEOUS-SOLUTION PROPERTIES OF POLY(SULFOBETAINE)S DERIVEDFROM STYRENE-MALEIC ANHYDRIDE

The copolymer prepared by copolymerizing styrene and maleic anhydride was imidized with N,N'-dimethylaminopropyl amine. The styrene-N,N'-dim ethylaminopropyl maleimide (SDMAPM) copolymer obtained was then reacte d with propane sultone to yield a styrene-[N,N'-dimethyl(maleimidoprop yl)ammonium propane sulfonate] (SDMMAPS) copolymer. The cloud point an d intrinsic viscosity of this ampholytic SDMMAPS copolymer were determ ined in aqueous salt solutions. The effects of counter ions on the clo ud point and intrinsic viscosity of SDMMAPS were similar to their effe cts on these properties of other zwitterionic poly(sulfobetaine)s. The Huggins constants for SDMMAPS in aqueous salt solutions, however, wer e quite different than those of other sulfobetaine homopolymers, such as poly[N,N'-dimethyl(acrylamidopropyl) ammonium propane sulfonate], [ poly(DMAAPS]. The value of the constant was negative and increased as the intrinsic viscosity and salt concentration increased. This phenome non is mainly attributed to the presence of the styrene segment, a hyd rophobic group, in the SDMMAPS copolymer. (C) 1997 Elsevier Science Lt d.