Investigating the sorption influence of poly(vinyl alcohol) (PVA) at different crosslinking content

Polymer crosslinking has significant importance in the relevant retrofitting of the microstructure of polymer network in terms of polymer swelling, membrane performance and its stability. This research was focused on investigating the sorption influence on membrane selectivity in terms of measuring swelling of poly (vinyl alcohol) (PVA) at varying polymer crosslinking in alcohol/water solutions. ATR–FTIR spectra for different crosslinked PVA were obtained using Nicolet FTIR spectrometer, and solvent concentration was determined by refractometer. The experimental results showed that swelling degree decreased with increasing crosslinking content, which led to a more rigid polymer network structure resulting in less free volume as well as reduced absorbed liquid in the polymer. The addition of crosslinker resulted in the reduction of PVA hydrophilicity influencing the sorption of alcohol into the polymer. It was found that PVA at all crosslinking contents was selective towards ethanol in ethanol/water mixture and becomes more water selective in an isopropanol/water mixture.