Trijama R. Mohanty

Redox Polymerization of Acrylonitrile by V5+/Propane-1,2-diol System in Aqueous Sulfuric Acid

Abstract The kinetics of polymerization of acrylonitrile by the redox system V5+-propane-1, 2-diol in aqueous sulfuric acid at 40 to 50°C were studied. The rate of polymerization, V5+ disappearance, and chain lengths of polyacrylonitrile were measured. The kinetics are consistent with the formation of an intermediate complex between the diol and the oxidant whose decomposition leads to the initiating radical. A suitable kinetic scheme has been proposed and the various rate and energy parameters were evaluated.

Aqueous Polymerization of Methyl Methacrylate Initiated by the Bromate-Thiourea Redox System

Abstract The aqueous polymerization of methyl methacrylate initiated by the bromate-thiourea redox system in dilute HC1 has been investigated under nitrogen atmosphere. The rate of polymerization increases with increasing concentration of thiourea in the range 5 × 10−3−10 × 10−3 M. The percentage of conversion increases with increasing concentration of the catalyst, but beyond 1.5 × 10−2 M, there is a decreasing trend in the rate of polymerization. The rate of polymerization increases with increasing monomer concentration, but beyond 0.184 M the polymerization rate decreases due to gel effect. The rate of polymerization increases with temperature up to 35°C and beyond 40°C a decreasing trend is noticed. The effect of water miscible organic solvents, certain neutral salts on the rate of polymerization has also been investigated.

Redox Polymerization of Acrylonitrile: Kinetics of the Reaction Initiated by the Redox System 1-Propanol—Chromic Acid

Abstract The kinetics of the aqueous polymerization of acrylonitrile initiated by the chromic acid-1-propanol redox system was investigated under a nitrogen atmosphere. The rates of polymerization and the disappearance of Cr(VI) were measured. Chromic acid alone did not initiate the polymerization under deaerated and undeaerated conditions. Water-miscible organic solvents and neutral salts depress both the rate and the conversion. On the basis of the experimental observations of the dependence of the rate of polymerization Rp and the rate of disappearance of Cr(VI)-Rm on various variables, a suitable kinetic scheme was proposed and various rate and energy parameters evaluated.