Effect of High Temperature on Aging and Service Life Prediction of 2/1 Camphor Propellant

ABSTRACTThe 2/1 camphor propellant is widely used as the main charge in aerospace pyrotechnic devices. However, long‐term service of 2/1 camphor propellant in high‐temperature space environments can easily lead to its degradation, resulting in failures during the actuation of space pyrotechnics. To investigate the effects of high‐temperature aging, an artificially accelerated aging test was conducted at 75°C, 85°C, 95°C, and 105°C. Samples subjected to different aging conditions were characterized through apparent morphology analysis, thermal weight loss analysis, gas chromatography, closed bomb testing, and flame sensitivity testing. An improved exponential aging model was employed to establish degradation models for diphenylamine (DPA) content, peak pressure, and 50% ignition distance. According to the life model established with a half‐delay period and a 50% decrease of DPA content as the failure threshold, the predicted safety life of the 2/1 camphor propellant at 60°C was 1.2 and 0.48 years, respectively. When a 10% reduction in 50% ignition distance and a 10% decrease in peak pressure were set as failure thresholds, the life model predicted service lives of 3.7 and 4.4 years at 60°C, respectively. The results demonstrate that the 2/1 camphor propellant can still meet performance requirements after 2 years of service at 60°C. The findings provide valuable insights for the application of the 2/1 camphor propellant in space pyrotechnic devices.