Synthesis and characterization of polyacrylamidegrafted sodium alginate membranes for pervaporation separation of water + isopropanol mixtures

Abstract

Polyacrylamide-grafted-sodium alginate copolymers were prepared by persulfate-induced radical polymerization by using polymer-to-monomer ratios of 2 : 1 and 1 : 1. Polymers were characterized by Fourier transform infrared spectroscopy, differential thermal analysis, and viscosity. Membranes were prepared from the polymers, crosslinked with glutaraldehyde, and used in the pervaporation separation of water ϩ isopropanol mixtures at 30°C. Equilibrium swelling experiments were performed for mixtures containing 10 to 80 mass % of water in the feed. Both the grafted copolymer membranes were ruptured while separating 10 mass % of water in the feed mixture. However, beyond 20 mass % of water in the feed mixture, flux increased with increasing grafting ratio, while selectivity decreased. Pervaporation separation experiments were carried out at 30, 40, and 50°C for 20 mass % of water in the feed mixture. By increasing the temperature, flux increased, whereas selectivity decreased. Arrhenius activation parameters for pervaporation and diffusion decreased with increasing grafting ratio of the membranes.

Blend Membranes of Sodium Alginate/Poly(Styrene Sulfonic Acid) for Isopropanol Dehydration

“…Table 2 compares the present PV data with some of the reported data on flux and selectivity. The present results of NaAlg-PSSA(10) membrane are better than those of the published reports [16][17][18][19][20]. NaAlg, sodium alginate; CS, chitosan; pAAm, poly(acrylamide); PVA, poly(vinyl alchol); GG, guar gum; PEG, poly(ethylene glycol).…”

Antioxidant–polysaccharide conjugates for food application by eco-friendly grafting procedure

“…3 a possible mechanism of reaction is proposed. The hydroxyl radicals, generated by the initiator system, abstract H-atoms from the hydroxyl groups of the polysaccharides (STEP 1) with consequent formation of free-radical sites and the insertion of CA onto the biomacromolecules can occur (STEP 2) (Toti & Aminabhavi, 2004).…”

Alginate graft copolymers and alginate–co-excipient physical mixture in oral drug delivery

“…In the case of a-cyclodextrin-alginate conjugate, its crosslinking capacity with Ca 2+ is nonetheless less affected by chemical grafting thereby exhibiting a higher degree of drug release retardation than that of b-cyclodextrin. Poly(acrylamide)-g-sodium alginate [31,[137][138][139][140][141] The graft copolymer retains the gelling characteristics of alginate where it can crosslink with divalent or multivalent cations to form beads. Ba 2+ produces stronger hydrogel beads than Ca 2+ .…”