Kinetic Study on Aircraft-used Polymethyl Methacrylate under Different Oxygen Concentration

The decompositions of aircraft-used polymethyl methacrylate are studied by means of thermogravimetric analysis and differential thermal analysis.Four kinds of oxygen concentrations are used(5%,10%,15%,21%)and heating rates used vary from 15 ℃/min to 30 ℃/min.Improved Coats-Redfern method is used to determine the kinetic parameters and Doyle method was used to calculate the decomposition data.The active energy and pre-exponential factor both increase when the oxygen concentration decreases.The active energy is in the range 100-108kJ/mol and 87-92kJ/mol at the two heating rates when oxygen concentration decreases,while the pre-exponential factor is in the range(7-35)×10~6/s and(0.4-1)×10~(6)/s.The simulation of weight loss process accords with the real weight loss process well.