Kinetics and Mechanism of Hydroxymethylation of Melamine in Phosphate and Carbonate Buffers

Abstract

The hydroxymethylation of melamine was kinetically investigated in aqueous Na ₂1-1PO₄- N a₃PO₄ and NaHCO₃-Na₂CO₃ buffers. From Arrhenius plots of the rate constants of the base catalyst (PO₄^3- and CO₃^2-) reactions, the activation energies and frequency factors were obtained. On the basis of the kinetics, it was proposed that the reaction occurs by true general base catalysis, and it proceed by the attack of methanediol and the catalyst on the amino groups of melamine by concerted mechanism. The rate-determining step was postulated from the slope of the BrOnsted plot (0.8).