Hydrazine (N2H4) is a clear, colorless, hygroscopic liquid with a distinct, ammonia-like odor. It is a highly polar solvent, miscible with other polar solvents but immiscible with non-polar solvents.
The purity of Ultra Pure™ anhydrous hydrazine exceeds the requirements for both the Monopropellant Grade and High Purity Grade set forth in Military Specification MIL-PRF-26536G. Ultra Pure™ hydrazine is aniline-free. No aniline is detectable at the detection limit of specified analysis procedures.
Specifications for Anhydrous Hydrazine
Specifications for Monopropellant Grade, High Purity Grade and Ultra Pure™ hydrazine are given in Table 1 below. Physical properties of Ultra Pure™ hydrazine are given in Table 2 below. Many of these properties are similar to those of water.
Calca Solutions Ultra Pure™ Specifications
| Properties | Monopropellant(a) | High purity(a) | Ultra Pure™ |
|---|---|---|---|
| Hydrazine wt%, min. | 98.5 | 99.0 | 99.5 |
| Water wt%, max | 1.0 | 0.75 | 0.5 |
| Ammonia wt%, max. | 0.3 | 0.3 | |
| Particulate mg/L, max. | 1.0 | 1.0 | 1.0 |
| Chloride mg/kg (ppmw), max. | 5 | 5 | 5 |
| Iron mg/kg (ppmw), max. | 20 | 1.0 | 4 |
| Non-volatile residue mg/L, max. | 50 | 10 | 10 |
| Aniline wt%, max | 0.50 | 0.003 | Free (4) |
| Carbon dioxide(1) wt%, max | 0.003 | 0.003 | 0.003 |
| Carbonaceous Material, (Total of OVCM(2) + OCM(3) | 0.02 | 0.005 | 0.005 |
| NOTES: (1) Determination of carbon dioxide (CO2) content must be performed before all other analyses to prevent further absorption of CO2. (2) OVCM – Other volatile carbonaceous material as the total of unsymmetrical dimethylhydrazine (UDMH), isopropyl alcohol (IPA), and monomethylhydrazine (MMH). (3) OCM – Other carbonaceous material consisting of any impurity providing a positive FID response ahead of and trailing the hydrazine peak excluding OVCM and aniline (4) Not detectable at detection limits of all specified methods |
Footnotes
- a Military Specifications MIL-PRF-26536G
- b mg/1
- c Max
- d Not detectable at detection limits of all specified methods
- e Total as unsymmetrical (UDMH) monomethyl hydrazine (MMH), and alcohol
Anhydrous hydrazine is a strong reducing agent. Mixtures of hydrazine and very strong oxidizers are hypergolic (i.e., they auto-ignite on contact). Hydrazine and hydrazine blends are used as fuels in hypergolic bipropellant combinations. They also have other properties, such as high specific impulse. Anhydrous hydrazine in contact with platinum group metal catalysts will decompose in a controlled reaction and can be used as a monopropellant.
Ultra Pure™ hydrazine is very hygroscopic. It also readily absorbs carbon dioxide from the air. These two properties should be considered from a quality perspective when handling hydrazine.
hysical properties of anhydrous hydrazine are given in Table 2 below. Many of these properties are similar to those of water. In addition, anhydrous hydrazine is a strong reducing agent. They also have other properties, such as high specific impulse, which makes them valuable as aerospace fuels.
Table 2: Typical Physical Properties of Ultra Pure™
| pH | (1% solution) | 10.1-10.7 |
|---|---|---|
| Density | @ 25℃ (g/ml) | 1.004 |
| Viscosity | @ 25℃ (cp) | 0.9 |
| Vapor Pressure | (mm Hg @ 30.7℃) | 10 |
| Freezing Point | ℃ | 2 |
| Flash Point | TCC (℃) | 37.8 |
| TCC (℉) | 100 | |
| Boiling Point | @ 760 mm Hg (℃) | 113.5 |
| @ 760 mm Hg (℉) | 236.3 | |
| Flammable Limits in Air | (%by vol) | 4.7-100 |
