Effect of polyethylene oxide-polypropylene oxide block copolymer on gas permeation properties of polyurethane/polyvinyl acetate blend membranes

The permselectivity through immiscible blend membranes strongly depends on the membrane morphology, the specific volume fraction and the size and the shape of the dispersedand continuous phases [1]. The effect of the size and shape of micro-phases on transport properties of immiscible polymerblends have not been paid much attention [1]. Polyurethanes (PU) have been accepted as elastomers with high gas permeability. However, the use of PU membranes for gas separation is limited by their low selectivity [2]. Polyvinyl acetate (PVAc) as a glassy polymer is one of the mostinteresting compounds for blending due to its CO2 affinity [3]. A block copolymer has been commonly employed as acompatibilizer to control the size of the dispersed phase of thepolymer blends [4]. In this work we have studied the gaspermeation and thermal properties of thePU/PVAc/Polyethylene oxide-polypropylene oxide block copolymer (Pluronic) blends. In particular, we have studied the effect of the amount of Pluronic on permeability and selectivity of gases through the blends.