Vinyl polymerization initiated by ceric ion reducing agent systems in sulfuric acid medium

Abstract

SynopsisPolymerization of the monomers, methyl acrylate (MA) and methyl methacrylate (MMA) was carried out in sulfuric acid medium at 15°C. with the redox initiator system, ceric ammonium sulfate-malonic acid. There was no induction period, and a steady state was attained in a short time. There was found to be no polymerization even after 1 hr. in the absence of the reducing agent R. The initiation was by the radical produced from the Ce4+-malonic acid reaction. The rate of monomer disappearance was proportional to [MI l.6, [R]0.5, and [Ce4+]0.a--0.6, and the rate of ceric disappearance was directly proportional to [R] and [Ce4+]. Chain lengths of the polymers were directly proportional to [MI and inversely to [R] 'Iz and [Ce4 +] '1%. The experimental results were explained by a kinetic scheme involving the following steps: (a)oxidation of the substrate to give the primary radical which reacts with Ce4 + to give the products, ( b ) initiation by the primary radical, (c) propagation, and ( d ) termination of the growing polymer radicals by the mutual type. For the polymerization of acrylonitrile (AN) by the redox system, ceric ammonium sulfate-cyclohexanone (CH), in sulfuric acid at 15OC., the scheme was modified to include linear type of termination by Ce4 +, along with the mutual termina, tion to explain the results especially under conditions with [Ce4+] > [CHI..

Grafting of Methyl Acrylate onto Cellulose by Ceric Ion

“…Consequently, the rate constants which have been evaluated and listed in Table 2 are only approximate values and refer to limited ranges of reaction conditions. termination, they are in reasonable agreement with data found in the literaAithough the individual rate constants are dependent on the method of de- ture for the polymerization of MA initiated by the malonic acid-Ce(IV) redox system in sulfuric acid [24]. These are also listed in Table 2 for comparison.…”

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].…”

Aqueous polymerization of ethyl acrylate initiated by ceric ion‐reducing agent systems in nitric acid medium

“…When there is a dependency of R p on [Ce(IV)], the following equation can be used to evaluate the rate constant ratios,9 ( k i / k o ) and ( k p / k t 1/2 ) The values obtained are reported in Table 2 (Fig 9) and are comparable to the literature results 7. 9, 13, 14…”