Assessment of the stability of triethyleneglycol dinitrate (TEGDN) double-base propellants during storage using near-infrared reflectance spectroscopy

Abstract

The stability of triethyleneglycol dinitrate (TEGDN) double-base propellants plays a crucial role in its subsequent storage and usage. A discolouration time (DT) model has been developed using near-infrared reflectance spectroscopy (NIRS) to replace the conventional methyl violet (MV) test for evaluating the qualification of the stability of the propellants. The spectral modelling intervals were determined using competitive adaptive weighted sampling (CARS). The spectral pre-processing method and the number of factors were also determined for the model. For the DT model, the determination coefficient of the calibration and cross-validation (Rc2, Rcv2) were 0.98 and 0.97, respectively. The root means square error of the calibration and cross-validation (RMSEC, RMSECV) were 1.3 and 1.5, respectively. External validation was conducted using a prediction set, the determination coefficient of the prediction (Rp2) was 0.96, and the root mean square error of the prediction (RMSEP) was 2.0. The paired t-test results indicate no significant difference between the measurement results of the model and those obtained by traditional detection methods. The established DT model can be used to determine whether the stability of TEGDN double-based propellants is qualified, providing a better option for large-scale testing of the propellants.