Co-microencapsulate of ammonium polyphosphate and pentaerythritol and kinetics of its thermal degradation

Co-microencapsulated ammonium polyphosphate (APP) and pentaerythritol (PER) (M (A&P)) is prepared using melamine-formaldehyde (MF) resin by in situ polymerization method, and characterized by Energy dispersive spectrometer (EDS) and Fourier transform infrared (FTIR) spectra. Thermal stability of M (A&P) has been analyzed and compared with APP/PER mixture. In air atmosphere, the mass loss of M (A&P) at different heating rates was investigated using TGA. The kinetics of thermal degradation and activation energy was described using Flynn-Wall-Ozawa and Kissinger methods. It showed that there were two degradation stages. Expanded carbon structure with honeycomb was formed in the first stage between 200 and 450 °C. The second stage was the oxidation of carbon with E_a as high as 151.7 kJ/mol, so the expanded carbon had a good thermal stability. The reaction order of thermal degradation was found to be 0.935, so the mechanism of M (A&P) thermal degradation was controlled by the process of random nuclear formation and growth.