Investigation of thermal degradation characteristics of polyamide-6 containing melamine or melamine cyanurate via direct pyrolysis mass spectrometry

In this work the changes in thermal degradation characteristics of polyamide 6 (PA6) in the presence of melamine (Me) or melamine cyanurate (MC) were investigated systematically via direct pyrolysis mass spectrometry. Though thermal stability of PA6 was not affected by the presence of flame retardants, the changes in the products and in their distributions were detected. The reaction of carbonyl groups of PA6 with amine groups of melamine was the main cause for the changes in the product distribution. In the presence of melamine cyanurate, new products due to the reaction of cyanic acid generated by the decomposition of cyanurate, with the amine groups of PA6 were detected. Significant increases in the evolution temperatures of melamine and melamine cyanurate in the presence of PA6 were attributed to intermolecular interactions, most probably by H-bonding, with PA6.