Synthesis of partially hydrolyzed graft copolymer (H-partially carboxymethylated guar gum-g-methacrylic acid): A superabsorbing material

To synthesize a hydrolyzed graft copolymer, the reaction conditions have been optimized to afford maximum grafting followed by maximum absorbency by varying the concentrations of methacrylic acid (from 8 × 10−2 to 24 × 10−2 mol dm−3), potassium peroxymonosulphate (from 0.4 × 10−2 to 2.0 × 10−2 mol dm−3), silver nitrate (from 1.2 × 10−3 to 4.4 × 10−3 mol dm−3), hydrogen ion (from 1.0 × 10−3 to 9.0 × 10−3 mol dm−3) and partially carboxymethylated guar gum (from 0.4 to 1.8 g dm−3) along with N,N′-methylene bisacrylamide (3.0 × 10−3 to 7.0 × 10−3 mol dm−3). The optimum time and temperature for grafting were found to be 40 °C and 120 min, respectively. The saponification reaction of graft copolymer synthesized has been carried out using NaOH (1.5–3.5 N). The effect of methacrylic acid and N,N′-methylene bisacrylamide concentrations on swelling ratio for graft copolymer synthesized i.e. partially hydrolyzed graft copolymer (H-CmgOH-g-MAA) is investigated in water. The graft copolymer is characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.