Dinesh Kumar Mishra

Synthesis and characterization of a novel graft copolymer of partially carboxymethylated guar gum and N-vinylformamide.

Graft copolymer of partially carboxymethylated guar gum (CMGOH) and N-vinylformamide (NVF) was synthesized by free radical polymerization using 2,2-Azobis [2-(2-imadazolin-2-yl) propane] dihydrochloride (AIPH) as initiator. The effect of various reaction parameters such as concentration of NVF, CMGOH, sulphuric acid and AIPH, as well as reaction time and temperature were investigated, and the grafting conditions were optimized. Percent total conversion, % grafting, grafting efficiency (%) and percent add on under different conditions were evaluated and compared. The reaction mechanism for graft copolymerization discussed. Studies on swelling, metal ion uptake and flocculation properties were carried out in aqueous medium and the results obtained are presented and discussed. Both CMGOH and its corresponding graft copolymer samples were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. Looking at the reasonable results obtained, the synthesized graft copolymers CMGOH-g-NVF, may be exploited as potential candidates for some industrial important applications as flocculent superabsorbent, and other similar applications.

Synthesis of graft copolymer (CgOH-g-AGA): Physicochemical properties, characterization and application

A graft copolymer of κ-carrageenan and 2-acrylamidoglycolic acid (CgOH-g-AGA) was synthesized via free radical polymerization initiated by potassium peroxymonosulphate/malonic acid redox pair. For affording maximum percentage of grafting, optimum conditions were determined by varying the concentrations of κ-carrageenan, 2-acrylamidoglycolic acid, potassium peroxymonosulphate, malonic acid, hydrogen ion, time and temperature. The swelling, metal ion uptake and flocculation studies were investigated with water, three metals (Ni(2+), Pb(2+) and Zn(2+)) solutions, coal (coking and non-coking) suspensions, respectively. Both, polymer backbone and its corresponding graft copolymer samples were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.