Some physicochemical measurements of chitosan polymer in acetic acid-water mixtures at different temperatures

Polyacrylamide-grafted sodium alginate (PAAm-y-.Na-AIg) copolymcric membranes have been pre­ pared, characterized, and used in the pervaporation separation of 10-80 mass % water-containing tetrahydrofuran mixtures. Totally three membranes were prepared; (1) neat Na-A!g with 10 mass % of polyethylene glycol (PEG) and 5 mass % of polyvinyl alcohol (PVA), (2) 46 % grafted PAAm-y-Na-AIg membrane containing 10 mass % of PEG and 5 mass % of PVA, and (3) 93 % grafted PAAm-£-Na-Alg membrane containing 10 mass % of PEG and 5 mass % of PVA. Using the transport data, important parameters like permeation flux, selectivity, perva­ poration separation index, swelling index, and diffusion coef­ ficient have been calculated at 30°C. Diffusion coefficients were also calculated from sorption gravimetric data of water-tetrahydrofuran mixtures using Fick's equation. Arrhenius activa­ tion parameters for the transport processes were calculated for 10 mass 'lii of water in the feed mixture using flux and diffusion data obtained at 30,35, and 40°C. The separation selectivity of the membranes ranged between 216 and 591. The highest permeation flux cf 0.677 kg/m2 h was observed for 93% grafted membrane at 80 mass % of water in the feed mixture. *3 2(X)2 Wiley Periodicals, Inc. J Appl Polym Sri 86: 272-281,2002