Kinetics of vinyl polymerization initiated by ceric ion in aqueous solution

Abstract

SynopsisA systematic kinetic study of the thermal polymerization of methyl methacrylate, methyl acrylate, and acrylonjtrile initiated by ceric ion in aqueous perchloric, nitric, and sulfuric acid solutions, has been made. The polymerization experiments were conducted in the dark a t 35OC. under conditions of negligible oxidation of water by ceric ion. The polymerization was found to proceed without an induction period, and the stesdy-etate rate waa attained in a short time. The rate of monomer disappearance (followed by gravimetry) was found to bear a square dependence on monomer concentration and is independent of both the ceric and hydrogen ion concentrations. The rate of ceric disappearance (followed by titrimetry or spectrophotometry) waa found to be directly proportional to the ceric, monomer, and hydrogen ion concentrations. The chain lengths of the polymers (determined viscometrically) were directly proportional to the monomer concentration and inversely to the ceric and hydrogen ion concentrations. Initially added cerous ion had negligible effect on the rates. Increase in ionic strength caused a slight increase in the rates. From experiments conducted at different temperatures, the activation energies for the various procesees in the reaction were calculated. Most of the experimental results were suitably explained by a kinetic scheme involving initiation and termination by ceric ion in the unhydrolyzed Ce4+ form.

Oxidative polymerization of acrylamide in the presence of thioglycolic acid

“…graft copolymers of vinyl monomers such as acrylonitrile, methylmethacrylate, acrylic or acrylamide [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Water-soluble polymers containing amine, hydroxyl, carboxyl or dicarboxylic end groups by using redox initiator system were synthesized [18][19][20][21][22][23][24].…”

Solvent effect on methyl methacrylate polymerization by cerium

“…[23][24][25] An alternative mechanism for the direct oxidation of the monomer by metal ions [25] is the reduction of the metal ions by the solvent (Mn 4+ oxidizes water producing OH free radicals).…”

Polymerization of Acrylonitrile Initiated by Cerium(IV) / p-Aminoacetophenone Redox System - A Kinetic Study

“…It is known that Ce(IV) is an one electron oxidant capable of oxidizing compound in sulfuric acid. Oxidation of any substrate by Ce(IV) occur through a single electron transfer from the substrate to the oxidant 11 . The mechanism of RESEARCH ARTICLE oxidation of cerium in many cases is simpler than the cases with other transition metal ions such as chromate, manganite ion etc.…”