Polyvinyl alcohol-phytic acid polymer films as promising gas/vapor sorption materials

Abstract

In this paper, we present the studies on gas/vapor sorption properties of polyvinyl alcohol/phytic acid (PVA/PA) composite polymeric films. To understand the gas sorption properties, we have performed the Brunauer − Emmet − Teller (BET) analysis of various PVA/PA polymeric films with varying weight percentages of PVA and PA. The films were mesoporous, while their specific surface area and average pore size were increasing with the gradual increase in PA compared to that of pure PVA. Observation in field emission—scanning electron microscope (FESEM) showed layered and porous morphologies of the PVA/PA polymer films, and hence they could trap gas molecules, aiding in efficient gas sorption. The tensile strength of the polymeric films decreased with the increase in quantity of PA, while the elongation at break increased with the increase in quantity PA content. Besides, vapor sorption studies provided evidence that the PVA/PA polymer films absorb water–vapor. The study showed a general trend of increasing vapor sorption with the increase in weight percent of PA. In particular, 2:3 PVA/PA polymer film showed the highest vapor sorption of 0.15 g moisture content per gram of the sample. Overall, our study reveals the potential use of PVA/PA composite polymeric films as gas/vapor sorption materials.