Thermal properties of cellulose-chitosan composite fibers

Abstract

Cellulose-chitosan composite fibers were obtained by the method of wet spinning from joint solutions in phosphoric acid. Thermogravimetry (TG), differential thermogravimetry (DTG) and differential scanning calorimetry (DSC) methods have been used to evaluate their thermal properties in the range of 20-600 °C in air atmosphere. It was found that the temperature of the maximum decomposition rate of composite fibers lies between the temperatures characteristic of individual components. It is shown that the addition of chitosan to cellulose leads to an increase in the mass of the carbon residue and gives the cellulosic fibers a self-extinguishing property. The observed effect is explained by the uniform distribution of cellulose and chitosan macromolecules and their aggregates separated by interphase layers in each other, in which a net of interpenetrating segments of both polymer macromolecules is represented. This provides the incombustibility for composite fibers with a chitosan content of more than 20 % and maintaining the integrity of the fibers after processing them with a solvent of chitosan-acetic acid.