关键词: 军用航空有机玻璃, 氧气浓度, 热重分析, 差热分析, 动力学, 改良的Coats-Redfern法

Abstract: 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)×10⁶/s and (0.4-1)×10⁶/s. The simulation of weight loss process accords with the real weight loss process well.

Key words: aircraft-used polymethyl methacrylate, thermogravemetric analysis(TG), differential thermal analysis(DTA), kinetic study, improved Coats-Redfern method