Conformational Conditions of Chitosan Macromolecules and Their Influence on the Efficiency of Chitosan Polymerization Process With 2-Hydroxyethyl Methacrylate and N-Vinylpyrrolidone

Abstract

Modification of chitosan with biocompatible synthetic polymers is important for the development of biodegradable medical materials with a tailor-made complex of properties. The issue of the influence of a polysaccharide macromolecule conformation on the synthesis and properties of the hybrid products remains acute. Conformational transitions of chitosan and their influence on the process of grafted polymerization of 2-hydroxyethyl methacrylate and N-vinylpyrrolidone onto the polymer and the properties of their copolymers were studied. To interpret the peculiarities of chitosan solutions properties, their viscosity was identified by the method of rotational viscometry; conformational transitions of the polymer polysaccharides were investigated by the method of spectrophotometry; dimensional characteristics of the polymer particles were assessed by the method of dynamic light scattering. Copolymers were characterized by the methods of IR-spectroscopy and gelpenetrating chromatography. Helix-coil conformational transition of the chitosan macromolecule was pH and temperature-sensitive. The effective size of the chitosan macromolecules for helix conformation was 14-35% larger than for the coil conformation. The grafted copolymer yield (98%) was significantly higher in the solutions of chitosan, where its macromolecules were in the coil conformation. The obtained results allow the researchers to create optimal conditions during the development of the copolymer-based biomedical materials with improved characteristics.