Pyrolysis and THM reactions of melamine and its resins

Melamine resins and a melamine polyester copolymer have been investigated with pyrolysis-GC/MS and thermally assisted hydrolysis and methylation (THM). Conventional pyrolysis yields characteristic volatile products only at temperatures above 500 °C and hexamethylenetetramine is the main product. A series of methylated melamines and secondary pyrolysis products were also found. THM yields high amounts of methylated melamines and therefore provides a sensitive method for the detection of melamine in resins and copolymers. Deduced from this results a preparative approach for the synthesis of methylated melamines with aqueous tetramethylammonium hydroxide solution was successfully developed.