AN INVESTIGATION OF THE THERMAL-DEGRADATION OF MELAMINE PHOSPHONITE BY XPS AND THERMAL-ANALYSIS TECHNIQUES

The thermal degradation of melamine phosphonite has been explored by XPS (or ESCA). This process is different from that of melamine. The melamine became a dimer at 400 degrees C, but triazine ring breakage occurred in melamine phosphonite in the range 250 to 300 degrees C evolving much ammonia. As a result, the carbonic ester bond was broken and the valence state of P was P5+ (P2O5) due oxidation. Before thermal degradation the chemical state of the phosphorus in melamine phosphonite is different from that after thermal degradation. It should be emphasized that XPS can be used for the structure analysis of sparingly soluble or insoluble samples.