Association of Carboxymethyl Chitin Macromolecules in Aqueous Solution

Abstract

The processes of association of 6-O-carboxymethyl chitin macromolecules (in salt and mixed forms) in aqueous solution are studied by dynamic light scattering. It is shown that the solution of 6‑O‑carboxymethyl chitin in the salt form contains two types of particles: small particles (9–16 nm) corresponding to the size of single macromolecules and larger (150–177 nm) associates. In the solution of the mixed form of 6-O-carboxymethyl chitin, only associated particles are present (80–800 nm). Using FTIR spectroscopy, it is shown that the association of 6-O-carboxymethyl chitin macromolecules in the aqueous solution is due to the formation of both hydrogen bonds and ion pairs between the functional groups of the polymer.