Separation of dimethyl carbonate/methanol mixtures by pervaporation with poly(acrylic acid)/poly(vinyl alcohol) blend membranes

A serial of poly(acrylic acid) (PAA)/poly(vinyl alcohol) (PVA) blend membranes with different PAA/PVA ratio were prepared for separating dimethyl carbonate (DMC)/methanol (MeOH) mixtures by pervaporation. FTIR was used to determine whether there was an esterification reaction between PAA and PVA. Swelling experiments were carried out in DMC/MeOH mixtures by using different blend membranes to investigate the swelling behavior of the membranes. The blend membranes with different PAA content were used to separate DMC/MeOH azeotrope through pervaporation experiments. The effects of operation temperatures and feed composition on pervaporation performances were also investigated. The results showed that the blend membrane containing 70 wt.% PAA had a highest separation factor of 13 and a permeate flux of 577 g/(m2 h) at 60 °C for separating DMC/MeOH azeotrope, which could be expected that the membrane prepared in this work should be used to separate DMC/MeOH mixtures in real application.