High Pressure Raman Spectroscopy of Nitric Acid / 2-Nitropropane Mixtures

Abstract

High pressure Raman spectroscopy measurements in a diamond anvil cell (0–20 GPa) on HNO3‐2‐nitropropane mixtures are reported. These mixtures have been chosen as a model propellant, where neither component is explosive by itself. The high pressure decomposition of the mixture with oxygen balance (O.B.=0) has been observed and the recovered products analyzed and identified. The initiation of the chemical decomposition is correlated with he weakening of the NO bonds in the mixture. The study of a mixture at O.B.=0 with H15NO3 permitted us to determine the origin of the nitrogen formation and to suggest a chemical pathway.

High Pressure Raman Spectroscopic Study of the Effects of n‐Ethylamines and Water on the 2‐Nitropropane/Nitric Acid System

“…A black spot is observed in the middle of the sample and the occurring of new peaks at 128, 192, and 260 cm À1 . These peaks, attributed to CO 2 (27, 187, 265, 1273, and 1391 cm À1 ) [15], suggest a partial decomposition of the sample [2]. Moreover, the presence of a new strong peak at 2236 cm À1 observed on Figure 10 could be attributed to N 2 O, and suggests that the partial decomposition gave place to the formation of this new compound.…”

“…Liquid systems of nitric acid (NA) and nitrocompounds have several practical advantages as propellants but remain still unused because of their hazardous behavior. The present communication is a contribution to the study of the effect of adding amines or water on the behavior of these systems [1,2].The spectroscopic measurements have been performed on the monopropellant model 2-nitropropane (2-NP)/NA. This system has been chosen as a model propellant, where neither of the components is explosive by itself.…”

“…The reactivity of this system is known to depend on a redox mechanism between the strong oxidizing donor (nitric acid) and the acceptor (nitrocompound) [6]. Different studies [2,4] show that the control of the donor-acceptor ratio is expected to modify the reactivity of the system. The sensitivity of the system can be enhanced by modifying the acceptor or the donor.…”

“…Raman spectroscopy has been used as a non-intrusive method to perform a microscopic analysis of the samples and high pressure is used as a suitable thermodynamic variable to study the evolution of the molecular interactions in the systems [2,7].…”

“…In previous works [2,8,9], the 2-NP/NA system has been studied in the liquid and solid state by high pressure Raman spectroscopy for different oxygen balances and the peaks have been assigned. Moreover, pure liquids triethylamine (TEA) and diethylamine (DEA) have been studied by high pressure Raman spectroscopy [10] and the peaks have been assigned [11].…”