Preparation and characterization of modified sodium carboxymethyl cellulose via free radical graft copolymerization of vinyl sulfonic acid in aqueous media

The present paper reports the graft copolymerization of vinyl sulfonic acid onto sodium carboxymethyl cellulose by free radical polymerization using potassium peroxydiphosphate/thiourea redox system in an inert atmosphere. The reaction conditions for maximum grafting have been optimized by varying the concentration of vinyl sulfonic acid (2.6 × 10−2–8.0 × 10−2 mol dm−3), potassium peroxydiphosphate (4.0 × 10−2–20 × 10−2 mol dm−3), thiourea (0.8 × 10−3–4.0 × 10−3 mol dm−3), sulphuric acid (1.0 × 10−3–6 × 10−3 mol dm−3), sodium carboxymethyl cellulose (0.6–1.6 g dm−3) along with time duration (60–180 min) and temperature (30–50 °C). Water swelling capacity, metal ion sorption, flocculation studies and resistance to biodegradability of synthesized graft copolymer have been performed with respect to the parent polymer. The graft copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis.