In this work we have carried out studies to determine the sorption capacity (swelling) of polymer polyurethane films based on amino esters of boric and orthophosphoric acids in pure components (water, isopropyl and ethyl alcohols) and water-alcohol mixtures (isopropanol-water, ethanol-water) at temperatures of 22, 40 and 60 °С. On the basis of the data on the sorption capacity of components through polymer films a preliminary assessment of the prospects of using the investigated polymers as a selective layer of pervaporation membranes is made. The changes in the volume-mass concentration of low-molecular-weight components in polymer films depending on the solvent concentration in the initial mixture and the temperature of the process have been determined experimentally. The obtained data are necessary for creating a mathematical model of the pervaporation separation process. The paper describes the developed methodology for the fabrication of polymer films based on amino esters of orthophosphoric and boronic acids. Hyperbranched polyols with high solubility and low characteristic viscosities were used as crosslinking agents in the synthesis of the studied polymers Experimental studies for water-alcohol mixtures were carried out in a wide range of alcohol concentrations (0-99 wt.%). The swelling dynamics of polymer films in water-alcohol mixtures and individual components were measured. For all films, a tendency of decreasing volume-mass concentration with increasing process temperature in isopropyl alcohol and water can be seen, but in ethyl alcohol the volume-mass concentration increases with exceeding the process temperature.
Read full abstract