The results of the constituent aging study (CAS) are given, where low‐temperature (T<64 °C) aging experiments were performed on over 1100 closed‐container samples of various combinations of the components of the plastic‐bonded explosive PBX 9501. Experiments were performed on the various combinations both in the absence and presence of free‐radical stabilizers. The product gases were identified and quantified as a function of aging time. The gas data show diverse chemistry between CAS samples and initial linear increases in product gas formation. Temperature analysis of the initial production rates of gas products shows straight Arrhenius plots. The extracted activation energies and frequency factors for the formation of the individual gas products yield a single linear kinetic compensation plot suggesting a common degradation pathway for PBX 9501 and combinations of constituents that contained nitroplasticizer (a eutectic mixture of bis‐2,2‐dintropropyl acetal and bis‐2,2‐dintropropyl formal).

Hydrolytic degradation data from a wide variety of experiments on Estane 5703, a commercial poly(ester urethane), are modeled with an AAC2 mechanism of reversible esterification and hydrolysis together with a cluster model for water concentration. The experimental conditions spanned a range of temperatures from 21 to 95 °C, relative humidities from 0 to 100%, times up to more than 30 years, and different initial molecular weights and acidities. In addition, the experiments were performed in several different laboratories with a number of different instruments and techniques. All the experimental data, both for molecular weight and acidity, are modeled with a single set of concentration‐independent rate coefficients, and the kinetic model fits the data well and constitutes a robust model of the hydrolytic degradation of this polymer. The results also show that ester hydrolysis is the dominant cause of the molecular weight loss of Estane 5703 in indoor storage at ambient temperatures and humidities. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1136–1151, 2003

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We report a 2.5-year study of the photolytic degradation of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with variations in temperature, humidity, and illumination by fluorescent and UV light (254, 312, and 365 nm). The free-radical decomposition product was monitored with electron paramagnetic resonance (EPR). The EPR spectrum of the green powder allowed reliable quantitation with a single peak (fwhm = 29.1 G). The variations in humidity showed little effect in accelerating the degradation of TATB. The only significant temperature effect was noticed at −10 °C, where fewer radicals formed. The radical production rates at −10 °C were some of the highest measured, however, suggesting that the rates under other temperature conditions had slowed, perhaps as a result of extensive conversion of surface molecules to radical species. We show that a substantial amount of radicals can be generated with UV light, and work is ongoing to modify our EPR spectrometer so that TATB can be irradiated in the EPR cavity to measure the initial rates of radical formation.