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The polymerization of acrylamide initiated by potassium peroxodi-phosphate in combination with different activators (viz., sorbose and thiourea) was studied in an aqueous medium at 40 0°C in an inert atmosphere. The rate of polymerization was found to be first power to the monomer and half power to the initiator concentration. Sorbose and thiourea have half and unit orders, respectively. The overall energy of activation was found to be 38 ± 2 and 47 ± 2 kJ/mol for peroxodi-phosphate/sorbose and peroxodiphosphate/thiourea redox systems, respectively. The effects of various additives, such as organic solvents, neutral salts, surfactants, and sulfuric acid, were studied. The viscometric-average molecular weight and the degree of polymerization were determined viscometrically.

The kinetics of polymerization of the divinyl monomer, i.e., N,N'-methylenebisacrylamide has been studied employing a peroxodiphosphate-thioacetamide redox system under inert atmosphere at 40±1°C. The rate of polymerization Rp, was proportional to [Monomer]1, [Thioacetamide]1.0, and [Peroxodiophosphate]0.5. Based on the experimental results, cyclopolymerization of the growing radicals and mutual termination has been proposed.

The kinetics of aqueous polymerization of acrylamide (AM) and methacrylamide (MAM) have been studied using a potassium peroxydiphosphate (PDP/Mn(II) system in an inert atmosphere at 40°C and at constant pH (1·30). The polymerization rate Rp has been found to be proportional to the half power of PDP and Mn(II) concentrations. The overall energy of activation (ΔE) was found to be 40·2±0·1kJmol-1 and 45·0±0.1kJmol-1 for AM and MAM, respectively. Intrinsic viscosity [η], viscometric average molecular weight (Mv) and number average degree of polymerization (Pn) at different concentrations of PDP, Mn(II) and monomer are reported. © 1998 SCI.

The kinetics of the palladium(II) catalysed oxidation of acrylic, methacrylic and crotonic acid by vanadium(V), in acid medium at constant ionic strength exhibit zeroth order dependence on vanadium(V) and first order dependence on palladium(II) and the unsaturated acid. Complex formation between the palladium(II) species and the unsaturated acid, with possible exchange of chloride ion and hydrogen ion in two successive steps, was invoked. The reaction rate is determined by a rearrangement leading to elimination of chloride ion. A plausible mechanism is proposed.

The polymerization of acrylamide initiated by potassium peroxodiphosphate in combination with different activators (viz., sorbose and thiourea) was studied in an aqueous medium at 40 ± 0°C in an inert atmosphere. The rate of polymerization was found to be first power to the monomer and half power to the initiator concentration. Sorbose and thiourea have half and unit orders, respectively. The overall energy of activation was found to be 38 ± 2 and 47 ± 2 kJ/mol for peroxodiphosphate/sorbose and peroxodiphosphate/thiourea redox systems, respectively. The effects of various additives, such as organic solvents, neutral salts, surfactants, and sulfuric acid, were studied. The viscometric-average molecular weight and the degree of polymerization were determined viscometrically.

No ligands or additives are necessary for the oxidation of aldehydes or primary alcohols into carboxylic acids or of secondary alcohols into ketones.

A simple and efficient method is developed for sulfides and disulfides.

A simple and chemoselective method for the oxidation of sulfides and disulfides to disulfoxides is developed.