Crosslinked poly(vinyl alcohol) membranes for separation of dimethyl carbonate/methanol mixtures by pervaporation

摘要

Novel polymer membranes were prepared mainly by poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA), and glutaraldehyde (GA) for the separation of methanol (MeOH) from dimethyl carbonate (DMC)/MeOH mixtures by pervaporation. The membranes of different GA content were characterized by contact angle, Fourier transform infared spectra (FT1R), X-ray diffractometer (XRD), and dynamic mechanical analysis (DMA). Swelling experiments were tested in DMC/MeOH mixtures to evaluate the membranes of different GA content. Besides, the effects of GA content in membrane, operating temperature, and feed composition on pervaporation performances were observed: the flux increased but the separation factor increased first and then decreased with increasing the GA content in membrane; the flux increased but the separation factor decreased with increasing the operation temperature or the MeOH concentration in feed. The results demonstrated that the crosslinked PVA membrane prepared in this work had an excellent selectivity: the MeOH concentration in permeate side was always higher than 98.6 wt% for separating feed mixtures of 40-70 wt% MeOH at 50-70 °C.