Synthesis and characterization of chitosan‐g‐methacrylic acid and studies of its additional physicochemical properties, such as swelling, metal‐ion sorption, and flocculation behavior

Abstract

AbstractThe aim of this study was to examine the synthesis of a graft copolymer of chitosan and methacrylic acid (MAA) by free‐radical polymerization with a potassium peroxymonosulfate/cyclohexanone (CY) redox system in an inert atmosphere. The optimum reaction conditions affording maximum grafting ratio (%G), grafting efficiency (%E), add on (%A), and conversion (%C) were determined. The grafting parameters were found to increase with increasing concentration of MAA up to 24 × 10−2 mol/dm3, but thereafter, these parameters decreased. With increasing concentration of peroxymonosulfate from 0.6 × 10−2 to 1.2 × 10−2 mol/dm3, %G, %A, and %E increased continuously. All of these grafting parameters increased with increasing concentration of CY up to 1.2 × 10−2 mol/dm3, but beyond this concentration, the grafting parameters decreased. With various concentrations of chitosan from 0.6 to 1.4 g/dm3, the maximum %G, %A, and %E were obtained at 1.4 g/dm3. %G, %A, and %C decreased continuously with various concentrations of hydrogen ions from 2 × 10−3 to 6 × 10−3 mol/dm3. The grafting parameters increased with increasing temperature up to 35°C, but thereafter, these parameters decreased. With increasing time period of reaction from 60 to 180 min, %G, %A, and %E increased up to 120 min, but thereafter, these parameters decreased. The graft copolymer was characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009