Graft Polymerization of Acrylamide onto Starch Using Ferrous‐Starch Thiocarbonate‐Persulphate Redox System

Graft copolymerization of acrylamide (Aam) onto starch using ferrous‐starch thiocarbonate‐persulphate redox system was investigated under different conditions including alkali concentration in the precarbon disulphide treatment, potassium persulphate concentration, ferrous ion concentration, monomer concentration, pH of the polymerization medium, polymerization temperature, use of solvent/water mixture instead of aqueous medium, and liquor ratio. The role of thiocarbonation on the magnitude of grafting of acrylamide onto starch has been studied with respect to K 2 S 2 O 8 and ferrous ion concentrations. The graft yield was significantly favoured in acidic medium as well as by increasing the persulphate concentration, acrylamide concentration, and polymerization temperature. Carbon tetrachloride constitutes the optimal medium for polymerization. Grafting was also favoured in either higher or lower liquor ratios.