On‐Line Auto Mass Measurement of Residual Solvent Mass and its Influence on Mechanical Properties of Propellants

An on-line auto mass measurement approach was applied to study the volatilization of residual solvents during the drying process of a single-based propellant, a double-based propellant containing triethyleneglycol dinitrate (TEGDN propellant, denoted as TEGDN-1) and a TEGDN propellant containing RDX (denoted as TEGDN-2). Drying experiments were conducted at a temperature of 50 degrees C, steady humidity, and atmospheric pressure. According to the drying rate curves obtained by the on-line auto mass measurement approach, it took 44h, 31h and 38h, respectively, for the residual solvent contents of the three kinds of propellants to come to an equilibrium point, which is approximately below 1%. The mechanical properties of propellant strands with different residual solvent contents were tested by a universal testing machine and dynamic thermomechanical analysis (DMA). The results indicate that the mechanical properties of the single-based propellant, TEGDN-1 and TEGDN-2 are influenced by the residual solvent content. The propellant strands are sufficiently plastic and elastic to be cut without being deformed at a broad range of temperature when they are dried to residual solvent contents of 5.8-3.6%, 9-5.7%, and 9.7-6.2%, respectively. In the drying experiment, the on-line auto measurement approach of the residual solvent mass of propellant strands is a highly promising method in view of its improvement in the cutting efficiency of propellant strands.