POLY(SULFOBETAINE)S AND CORRESPONDING CATIONIC POLYMERS .5. SYNTHESISAND DILUTE AQUEOUS-SOLUTION PROPERTIES OF POLY(SULFOBETAINE)S DERIVEDFROM ACRYLAMIDE MALEIC-ANHYDRIDE COPOLYMER

The copolymer prepared by copolymerizing acrylamide with maleic anhydr ide was imidized with N,N-dimethylaminopropylamine. The obtained acryl amide-N,N-dimethylaminopropylmaleimide (ADAPM) copolymer was then reac ted with propane sultone to yield a novel acrylamide-N,N-dimethylmalei midopropylammonium propanesulfonate (ADMMAPS) copolymer. The propertie s of this ampholytic ADMMAPS copolymer in aqueous salt solution were s tudied by measurement of reduced viscosity and intrinsic viscosity. Th e intrinsic viscosities of this polyampholyte were related to the type and concentration of the added salts. 'Soft' salt cations and anions were more easily bound to the quaternary ammonium (R(4)N(+)) and sulfo nate group (SO3-) of ADMMAPS than were 'hard' salt cations and anions. The tendency of the intrinsic viscosity for ADMMAPS in various aqueou s salt solutions is similar to that of other zwitterionic poly(sulfobe taine)s. The Huggins constant for ADMMAPS in an aqueous salt solution shows a marked distinction from the sulfobetaine copolymer, styrene-N, N-dimethylmaleimidopropylammonium propane sulfonate (SDMMAPS). This ph enomenon is attributed mainly to the presence of the acrylamide/styren e segment, a hydrophilic/hydrophobic group, on the ADMMAPS/SDMMAPS cop olymer, respectively. Copyright (C) 1996 Elsevier Science Ltd.