Preparation and characterization of microcapsulated red phosphorus and its multi-step thermal oxidation processes based on kinetic approach

Resumo

Aluminium hydroxide/melamine–formaldehyde resin microcapsulated red phosphorus (MRP) was successfully prepared by two-step processes. The microcapsulated red phosphorus was characterized with Fouriertransform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Meanwhile its water absorption, thermostability were also determined. The results show that the MRP exhibited lower water absorption and higher thermostability compared with red phosphorus (RP) itself. Moreover, the thermal oxidative decomposition kinetics of MRP was investigated by TG/DTG and DTA in air atmosphere using non-isothermal experiments. The results show that the MRP’s decomposition consisted of two steps. And the apparent activation energies E_α was determined by applying both the Ozawa–Flynn–Wall (OFW) and Kissinger, Akahira and Sunose (KAS) methods. It was found that the dependence of E_α on α is complex. Both of the steps in this study fitted Sestak–Berggren (SB) model in overall reaction controlled kinetics and the corresponding model parameters, n, m, A were obtained. The simulated curves were fitted to experimental curves by plotting dα/dt vs. temperature at different heating rates.