Dilute solution properties of naphthalene-labeled cationic poly(dimethyl sulfate quaternized acrylamide/N,N-dimethylaminopropylmaleimide copolymer)

The properties of a novel cationic, naphthalene-labeled cationic poly(dimethyl sulfate quaternized acrylamide/N,N-dimethylaminopropylmaleimide copolymer), poly-(DSQADMAPM)/NA in aqueous solution are examined in this study, measuring intrinsic viscosity, reduced viscosity, and ionic strength. This cationic poly(DSQADMAPM)/NA’s intrinsic viscosity is dependent on the type and concentration of salt added to the aqueous solution. The intrinsic viscosity behavior of the cationic poly(DSQADMAPM)/NA resulting from the electrostatic repulsive force of the polymer chain is contrasted with polyampholyte. Smaller anions such as F⁻ with a common cation (K⁺) are found to be the most difficult to be bound to the end group, indicating that a higher intrinsic viscosity of the poly(DSQADMAPM)/NA would be in KF salt aqueous solution. Smaller cations such as Li⁺ with a common anion (Cl⁻) are found to be the most difficult to be bound to the quaternary ammonium group, indicating that a higher intrinsic viscosity of the poly(DSQADMAPM)/NA would also be in LiCI salt aqueous solution. Models are proposed to account for the poly(DSQADMAPM)/NA solution viscometrics.