THE RESTORATION OF THE CAPILLARY-POROUS STRUCTURE OF CELLULOSE DURING HEAT TREATMENT AND PROCESSING BY MOISTURE

Abstract

The influence heat treatment and processing by moisture on the hydrophilic properties of cellulose fibers. The possibility of using this treatment to restore the capillary-porous structure of cellulose, which had been lost during drying of pulp folder. Revealed peculiarities of the structure of cellulose when exposed of water vapor of high parameters of state. In the basis of understanding what is happening in this effect are the experimental data obtained by calorimetry and sorption. For the first time on the basis of experimental data the calculated thermodynamic functions of hydration of water by cellulose, subjected to hydrothermal effects in a wide range of humidity and temperature. On the basis of experimental data the calculated thermodynamic functions of sorption of water by cellulose obtained in the optimal regime of heat, processing by moisture (438 K, 4 min). These terms of processing indicate an increased content of active sites available for interaction with water. Prolonged exposure reduces hydrophilic properties of the treated pulp as a result of the process of secondary crystallization, which is typical for polymers in highly elastic condition. Consequently, in conditions of constant temperature and humidity can occur as the increase of hydrophilic properties of cellulose and hydrophobicity of the polymer depending on the conditions of hydrothermal influences.