Synthesis and characteristics of the poly(carboxybetaine)s and the corresponding cationic polymers

Abstract

Two types of carboxybetaines and their corresponding cationic monomers and polymers are synthesized in this study. Comparing the chemical shifts of the methylene groups in the cationic monomers and carboxybetaines in both 1H- and 13C-NMR spectra reveal that the respective methylene groups are clearly distinguished from their chemical shifts in 1H- and 13C-NMR spectra. The solubilities, moisture regain properties, and solution properties of the poly(carboxybetaine)s and cationic polymers are investigated in relation to their molecular structures. Because the cationic polymers were ionized in an aqueous solution, the cationic polymers were more soluble than the poly(carboxybetaine). For the various functional groups of poly(carboxybetaine)s and cationic polymers, the order of tendency for moisture regain is - COO - > - CONH - . Results obtained from the reduced viscosity for cationic poly (TMM-PAMS) are reversed from that for zwitterionic poly (DMAEAPL). © 1997 John Wiley & Sons, Inc.