Influence of thermal effects on the transport characteristics of cellulose acetate porous films

Experimental data have been obtained, and the characteristics of the moisture content and permeability of cellulose acetate porous materials were analyzed via thermal action. Dynamic thermogravimetric analysis found that the destruction process in an air-dry sample of the membrane begins at $21^{\circ}$C. It is accompanied by a $2\%$ weight loss and an endothermic effect. The destruction ends at $50^{\circ}$C. With a subsequent increase in temperature, the manifestation of endothermic effect continues a temperature of $120$–$175^{\circ}$C with the maximum rate of mass loss at $146^{\circ}$C. The weight loss ends at about $190^{\circ}$C and is $6.5\%$. The study of MGA-80 and MGA-95 porous cellulose acetate films at transmembrane pressure upon temperature exposure showed that the permeability and specific output flow to water increase as the temperature rises to $50^{\circ}$C. Analysis of dependences of the specific output flow on temperature revealed that the specific output flow to water increases by $\sim18\%$ upon an initial temperature rise of $10^{\circ}$C. This is due to structural changes in the cellulose acetate layer. A further increase in temperature by $15^{\circ}$C leads to an increase in permeability by $\sim10\%$. These phenomena are associated with the process of structural transformation in the active layer and the polymer substrate of the MGA-95 and MGA-80P membranes, respectively.