Determining energetic characteristics and selecting environmentally friendly components for solid rocket propellants at the early stages of design

This paper has investigated the possibility to theoretically calculate a value of the specific impulse for highly energetic compositions using only two parameters – the heat of the reaction and the number of moles of gaseous decomposition reaction products. Specific impulse is one of the most important energetic characteristics of rocket propellant. It demonstrates the level of achieving the value of engine thrust and propellant utilization efficiency. Determining the specific impulse experimentally is a complex task that requires meeting special conditions. For the stage of synthesis of new promising components, the comparative analysis of energetic characteristics, forecasting the value of specific impulse, especially relevant are calculation methods. Most of these methods were first developed to determine the energetic characteristics of explosives. Since explosives and rocket propellants in many cases have similar energy content and similar chemical composition, some estimation methods can be used to assess the specific impulse of solid rocket propellant. The specific impulse has been calculated for 45 compositions based on environmentally friendly oxidizers (ammonium dinitramide, hydrazinium nitroformate, hexanitrohexaazaisowurtzitane) and polymer binders polybutadiene with terminal hydroxyl groups, glycidylazide polymer, poly-3-nitratomethyl-3-methyloxetane). It was established that the estimation data obtained correlate well with literary data. Deviation of the derived values of the specific impulse from those reported in the literature is from 0.4 % to 1.8 %. The calculation results could be used for preliminary forecasting of energetic characteristics for highly energetic compositions, selecting the most promising components, as well as their ratios.

Novel Polyurethanes Based on Recycled Polyethylene Terephthalate: Synthesis, Characterization, and Formulation of Binders for Environmentally Responsible Rocket Propellants

Novel polyurethane-based binders, specifically designed for environmentally responsible rocket propellant composites, were obtained by employing the polyester-polyols that resulted from the degradation of polyethylene terephthalate waste. A new class of “greener” rocket propellants, comprising polyurethanes (based on recycled PET) as the binder, phase stabilized ammonium nitrate (PSAN) as the eco-friendly oxidizer, and triethylene glycol dinitrate (TEGDN) as the energetic plasticizer, together with aluminum as fuel and Fe2O3 as the catalyst, is herein reported. The components of the energetic mixtures were investigated (individually and as composite materials) through specific analytical tools: 1H-NMR, FT-IR, SEM-EDX, DTA and TGA, tensile and compression tests, DMA, and micro-CT. Moreover, the feasibility of this innovative solution is sustained by the ballistic performances exhibited by these composite materials in a subscale rocket motor, proving that these new formulations are suitable for rocket propellant applications.

Performance Analysis of a Dual-Fuel Sugar Based Solid Rocket Propellant

The effects of dual-fuel on improving the ballistic efficiency of a low energy sugar-based solid rocket propellant were investigated in this paper. This was achieved by establishing a threshold proportion of sucrose to sorbitol that provided the highest ballistic efficiency, using a beam load cell (model single-point 2,000 kg linearly defined by 0-20 kN force, with ±.005 percent precision). Seven different propellant formulations were prepared, loaded into the rocket motor and tested for performance. The major performance parameters of interest were the thrust, total impulse, burn time, delivered specific impulse, delivered characteristic velocity, and the chamber pressure. The formulations tested were potassium nitrate–sucrose propellant (65% KNO3 and 35% sucrose (C12H22O11)) (KNSU); potassium nitrate-sorbitol propellant (65% KNO3 and 35% sorbitol (C6H14O6)) (KNSB); modified potassium nitrate-sucrose propellant (65% KNO3, 32% sucrose (C12H22O11)), and 3% carbon (C) (MODKNSU); potassium nitrate-sucrose-sorbitol propellant (65% KNO3, 25% sucrose (C12H22O11)), and 10% sorbitol (C6H14O6) (KNERK); potassium nitrate-sucrose-sorbitol-carbon propellant (65% KNO3, 24% sucrose (C12H22O11), 10% sorbitol (C6H14O6), and 1% carbon (C)) (MODKNERK); and finally a propellant made from KNO3, sucrose (C12H22O11), sorbitol (C6H14O6), carbon (C) and iron II oxide(Fe2O3) combinations in 65, 30, 3, 1, 1% proportion respectively. The novel result obtained from these experiments was applied to boost the performance of a KNSB rocket propellant motor during a rocket launch experiment. Both static and dynamic rocket motor internal ballistic parameters were then compared. The measured delivered motor average thrust and the effective propellant burn times were recorded as: (164.15N, 3.97s); (102.95N, 6.53s); (65.66N, 9.38s); (79.09N, 3.77s); (243.98N, 3.77s) and (92.6N, 5.89s) respectively. The MODKNERK, was established to produce a most efficient motor and with the full delivery of its ballistic energy. It was also established, that the ballistic and rocket motor efficiency of a lower energy rocket motor can be improved by starting the ignition of such motor with fast burning dual-fuel rocket propellant (MODKNERK).

Sustainable plasma-catalytic bubbles for hydrogen peroxide synthesis

Hydrogen peroxide (H2O2) is a green oxidant widely used in various fields, from water treatment to rocket propellant. Currently, H2O2 is predominantly manufactured via the anthraquinone process, which requires large...