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The kinetics of aqueous polymerization of acrylamide with KMnO4/glycine redox pair was studied in an atmosphere of nitrogen at 35 ± 0.2°C. The rate of polymerization was found to be first power on monomer, activator, and catalyst concentration. The overall energy of activation was calculated to be 15.66 kcal/deg mol (65.54 kJ/mol) between 30 and 50°C. The effects of various additives (alcohols, neutral salts, complexing agents, addition of catalyst) were studied. The dependence of the polymerization rate on the activator and catalyst concentration was studied in DMF‐water mixture also. The molecular weight of polymer was determined at various temperatures of the reaction medium.

The grafting of poly(acrylonitri1e) onto guar gum in aqueous medium initiated by the potassium presulfate/ascorbic acid redox system has been studied gravimetrically at the temperature of 35 + 0.2"C in the presence of atmospheric oxygen. A plausible mechanism of graft copolymerization has been suggested on the basis of experimental results. The effect of grafting on the water and saline retention capacities has been studied and compared with the values obtained for ungrafted guar gum.

The grafting of acrylamide onto guar gum in aqueous medium initiated by the redox system Cu2+/Na2S2O5 in presence of oxygen has been studied at the temperature 35°C. The effect of the concentration of the components of the grafting system and of the reaction temperature has been determined. A plausible mechanism of the grafting process is suggested.

SynopsisThe grafting of polyacrylamide on to guar gum in aqueous medium initiated by the potassium persulfate/ascorbic acid redox system has been studied gravimetrically at the temperature 35 0.2"C in the presence of atmospheric oxygen and Ag+ ions. The rate of grafting was found to increase with temperature, concentration of redox components, acrylamide, and guar gum. But a t higher concentration of guar gum, the rate of grafting was found to decrease. A mechanism for grafting and suitable rate expression have been suggested.