Interactions and chain mobilities of O-carboxymethyl-O-2-(diethylamino)ethylcellulose in aqueous solutions

The hydrophobic interactions between the 2-(diethylamino)ethyl substituents of O-carboxymethyl-O-2-(diethylamino)ethylcellulose in aqueous solutions were studied by gel permeation chromatography (g.p.c.). Intermolecular associations caused by the hydrophobic interactions between the 2-(diethylamino)ethy1 substituents occur in 0.10 M NaOH, and such intermolecular hydrophobic interactions are restrained when the extension of chains is depressed as a result of the addition of NaCl. The mobilities of the carboxylmethyl and 2-(diethylamino)ethy1 substituents (protonated or non-protonated) were evaluated from their C-13 nuclear magnetic resonance (n.m.r.) spin-lattice relaxation times, and were found to be affected by the interaction between the substituents, distance from the cellulose chains, and degree of solvation. Copyright (C) 1996 Elsevier Science Ltd.