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The kinetics of thermal polymerization of methyl methacrylate initiated by the redox system Mn(III)–glycerol was studied in aqueous sulfuric acid in the temperature range of 30–40°C, and the rates of polymerization, Rp, and Mn3+ disappearance, etc., were measured. The effect of certain water‐miscible organic solvents and certain cationic and anionic surfactants on the rates of polymerization has been investigated. A mechanism involving the formation of a complex between Mn3+ and glycerol whose decomposition yields the initiating free radical with the polymerization being terminated by the metal ion has been suggested.

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SynopsisVinyl polymerization of acrylonitrile initiated by the Ce(IV)/thioacetamide redox system has been investigated in aqueous sulfuric acid in the temperature range of 10-2OoC. The rate of polymerization (R,) and the rate of Ce(1V) disappearance (-Rce) were measured. The effect of certain water-soluble organic solvents, added electrolytes, and aromatic and heterocyclic organic nitrogen compounds on the rate of polymerization has been investigated. Depending on the experimental results, we have suggested a suitable reaction scheme for the system which involves the production of initiating radicals from the oxidation of thioacetamide (TAm) by ceric ion and the termination of the polymer chain by metal ions.

The use of trivalent manganese to initiate graft-copolymerization of acrylamide onto nylon-6 has been investigated. The rate of grafting has been determined by varying monomer, manganese(III), temperature and solvent mixtures. The graft yield increases with increasing monomer concentration up to 0.8 M and with further increase of monomer concentration the graft yield decreases. The percentage of grafting increases with manganese (111) ion concentration up to 5.25 x 10-3M and thereafter it decreases. The rate of reaction depends on temperature. Among the solvent composition studied, a water/solvent mixture containing 25% of the solvent seems to constitute the most favourable medium for grafting and with further increase of solvent composition, the graft yield decreases.