Thermal stability of melamine formal‐dehyde resins

The temperatures given for the decomposition of melamine formaldehyde (MF) resins cover a wide range. An investigation of this decomposition using DTA, TG, EGD, and infrared techniques has shown that these variations are due to different criteria of stability and to errors in interpretation of thermoanalytical results. There is considerable loss of formaldehyde at 200°C which makes this the maximum temperature for the use of MF resins in paints. Contrary to earlier results the triazine ring is not decomposed below 400°C and the main decomposition reaction is the breaking of methylene bridges around 380°. Under oxidative conditions the decomposition occurs at lower temperatures but the mechanism is not yet clear.