Syntheses of hydroxypropyl methylcellulose phthalate gels in organic solvents by radiation crosslinking

Abstract

Cellulose gels were prepared through the crosslinking of hydroxypropyl methylcellulose phthalate (HPMCP) with electron-beam irradiation in concentrated organic solvent solutions. The effects of the solvent species, polymer concentration, and irradiation dose on the formation of the gels were investigated. Some organic solvents, such as alcohols with short alkyl chains, alkyl acetates, and ketones, were found to be suitable as media for the radiation crosslinking of the polymer. The prepared HPMCP gels showed excellent swelling in various organic solvents with medium hydrogen-bonding abilities, such as pyridine, cresol (meta), acetic acid, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, 1,4-dioxane, acetone, methyl ethyl ketone, methyl acetate, and chloroform. In an acetone/water mixture, the swelling ratio was significantly dependent on the solvent composition because of the coexistence of both hydrophilic and hydrophobic moieties in HPMCP. These results suggest that HPMCP gels have the potential to be superabsorbents for various kinds of organic solvents. © 2004 Wiley Periodicals, Inc.