Accelerated thermal aging of glass-reinforced epoxy resin under oxygen pressure

Accelerated thermal degradation of glass-reinforced epoxy resin was studied under the following conditions: 1. (a) in air at atmospheric pressure, and temperatures 145, 160, 180 and 190°C; 2. (b) in oxygen at 117°C and 5 atm; 125°C and 3 atm; 125°C and 5 atm; and 145°C and 5 atm. The changes in flexural strength as a result of the accelerated thermo-oxidative degradation was studied. The importance of oxygen pressure as an accelerating factor in thermo-oxidative degradation was demonstrated. Experimental results led to a kinetic equation for the dependence of degradation on temperature, pressure and duration of the accelerated thermal aging. Verification of this equation for all the experimental data obtained suggests that both in air and in oxygen the same mechanism of thermo-oxidative degradation of glass-reinforced epoxy resin applies.