Journal of Applied Polymer Science, Vol.86, No.9, 2194-2210, 2002
Pervaporative separation of a 1-methoxy propanol and water mixture
The pervaporative dehydration of ether derivatives of alcohol, such as 1-methoxy propanol (MP) and water mixtures, was studied with polyimide (PI), cellophane, poly(vinyl alcohol) (PVA), cellulose diacetate (CDA), cellulose triacetate, two separate blends of cellulose acetate and CDA with cellulose acetate propionate, and PVA crosslinked with multifunctional crosslinkers. The effects of different substitution derivatives of cellulosic materials were investigated. Membranes of PVA and citric acid and of PVA and maleic anhydride were studied with respect to the effect of the crosslinker and its loading. Among all the hydrophilic membranes, PI gave the best selectivity but poor flux. Poly(dimethylsiloxane) (PDMS) and linear low-density polyethylene (LLDPE) mernbranes were invoked for the selective permeation of comparatively weaker hydrophilic components. PDMS showed acceptable results for MP separation in terms of both flux and selectivity. LLDPE yielded better selectivity but very poor MP flux. All these membranes were stable, and no changes in their properties were observed over the entire range of concentration at 30degreesC.
Keywords:differential scanning calorimetry (DSC);NMR;polysiloxanes;crosslinking;blends;membranes;morphology;selectivity;swelling;separation techniques