Water soluble graft copolymer (κ-carrageenan-g-N-vinyl formamide): Preparation, characterization and application

κ-Carrageenan-g-N-vinyl formamide was synthesized by free radical initiation using the potassium monopersulphate (PMS)/malonic acid redox pair in an inert atmosphere. The effects of variation of different reactant on grafting parameters have been studied by varying the concentration. Grafting ratio, add on and conversion showed an increasing trend on increasing the concentration of N-vinyl formamide, malonic acid, κ-carrageenan and the concentration of PMS from 6 × 10−3 to 22 × 10−3 mol dm−3. The optimum temperature and time for grafting of N-vinyl formamide onto κ-carrageenan was found to be 40 °C and 120 min, respectively. The metal ion sorption, swelling behaviour, flocculation and resistance to biodegradation properties have been studied. Flocculation capability of κ-carrageenan and κ-carrageenan-g-N-vinyl formamide for both coking and non-coking coals has been studied for the treatment of coal mine waste water. The graft copolymer was characterized by FT-IR spectroscopy and thermogravimetric analysis.