Blend membranes of chitosan and poly(vinyl alcohol) in pervaporation dehydration of isopropanol and tetrahydrofuran

Abstract

Blend membranes of a natural polymer, chitosan, with a synthetic polymer, poly(vinyl alcohol) (PVA), were prepared by solution casting and crosslinked with a urea formaldehyde/sulfuric acid (UFS) mixture. Chitosan was used as the base component in the blend system, whereas PVA concentration was varied from 20 to 60 wt %. Blend compatibility was studied by differential scanning calorimetry, and Fourier transform infrared spectroscopy was used to study membrane crosslinking. Membranes were tested for pervaporation dehydration of isopropanol and tetrahydrofuran (THF) at 308C in close proximity to their azeotropic compositions. Membrane performance was assessed by calculating flux and selectivity. Swelling experiments performed in water þ organic mixtures at 308C were used to explain the pervaporation results. The blend membrane containing 20 wt % PVA when tested for 5 and 10 wt % watercontaining THF and isopropanol feeds exhibited selectivity of 4203 and 17,991, respectively. Flux increased with increasing concentration of water in the feed. Selectivity was highest for the 20 wt % PVA-containing blend membrane. The results of this study are unique in the sense that the crosslinking agent used-the UFS mixture-was novel.

Pervaporation dehydration of ethylene glycol with chitosan–poly(vinyl alcohol) blend membranes: Effect of CS–PVA blending ratios☆

“…Chitosan, a natural hydrophilic polymer, with good chemical resistance, biodegradability, and membrane-forming property, is commonly used to prepare hydrophilic blend membranes [8][9][10]. CS-PVA blend membranes have been reported to have good mechanical strength in addition to good membrane performance characteristics for pervaporation separation [11][12][13][14][15][16][17][18]. Lu et al [17] found that the permeation flux was dramatically increased (while selectivity was increased only slightly) through blending CS with PVA for benzene/cyclohexane mixtures.…”

“…Of theses methods, polymer blending proves to be an effective way to fabricate membranes with a number of desired properties [12][13][14]. Successful blending can improve separation performance by altering polymer chain mobility through intermolecular interactions between polymers [3].…”

Hydrogels for Potential Colon Drug Release by Thiol‐ene Conjugate Addition of a New Inulin Derivative

“…[6,7] Hydrogels can be prepared from natural, [4,[8][9][10] synthetic [2,3,11] and mixed natural/synthetic polymers. [5,12,13] Hydrogels made from natural polymers offer several advantageous properties, such as native biocompatibility, biodegradability and biologically recognizable moieties that support cellular activities. Hydrogels made from synthetic polymers, on the other hand, generally, do not possess these native bioactive properties, but usually they have well-defined structures that can be modified to reach the wanted degradability and functionality.…”

Chitosan Based Membranes for Separation, Pervaporation and Fuel Cell Applications: Recent Developments

“…It was concluded that the developed CS-BCM based membrane can be an alternate for use in PV dehydration of EtOH/H 2 O azeotrope mixture [159]. Sodium zeolite-Y (NaY zeolite) filled CS polymeric membranes were developed and characterized for the PV dehydration performances [160].…”