Formation of nanocrystalline h-AlN during mechanochemical decomposition of melamine in the presence of metallic aluminum

Decomposition of melamine was studied by solid state reaction of melamine and aluminum powders during high energy ball-milling. The milling procedure performed for both pure melamine and melamine/Al mixed powders as the starting materials for various times up to 48 h under ambient atmosphere. The products were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results revealed that Al causes melamine deammoniation at the first stages of milling and further milling process leads to the s-triazine ring degradation while nano-crystallite hexagonal aluminum nitride (h-AlN) was the main solid product. Comparison to milling process, the possibility of the reaction of melamine with Al was also investigated by thermal treatment method using differential scanning calorimeter (DSC) and thermo gravimetric analyzer (TGA). Melamine decomposition occurred by thermal treatment in the range of 270–370 °C, but no reaction between melamine and aluminum was observed. - Graphical Abstract: Mechanochemical reaction of melamine with Al resulted in the formation of nanocrystalline AlN after 7 h milling time Highlights: ► High energy ball milling of melamine and aluminum results decomposition of melamine with elimination of ammonia. ► Nano-crystalline AlN was synthesized by the mechanochemical route. ► Milling process has no conspicuous effect on pure melamine degradation. ► No reaction takes place by heating melamine and aluminum powder mixture in argon.