Titanium Hydride/ Potassium Perchlorate (THPP)
THPP is a “booster” pyrotechnic and is a blend of a fuel (titanium hydride. TiH2), an oxidizer (potassium perchlorate, KClO4) and binder, typically Viton. The primary use at Pac Sci EMC is as a pyrotechnic transfer composition where it converts the heat energy from a bridgewire pyrotechnic (usually ZPP) to generate a flame and hot particles which ignite an output charge. THPP affords a rapid pressure rise, emits hot particles and has good thermal stability.
Why We Like It
THPP was designed to be much safer (from an ESD perspective) to use during manufacturing operations compared to TiKP which contains titanium metal (similar to ZPP) and is extremely ESD sensitive. THPP also has a lower ignition sensitivity and slower burn rate compared to TiKP and, while both materials are used in ordnance devices, they frequently have different applications. THPP is prepared at Pac Sci EMC from commercially available titanium hydride powder, finely ground potassium perchlorate and a small percentage of Viton binder utilizing a shock gel mixing method.
How You Should Handle It
Like ZPP, THPP requires both assembly personnel and hardware used in manufacturing processes to be efficiently grounded and have extensive PPE due to the ESD sensitivity of the composition. THPP, both bulk and pressed, has been found to be insensitive to initiation from a “typical” human body static discharge and so is considered safe relative to TiKP or TiH<2PP (titanium or titanium subhydride). Minor compatibility issues between THPP and typical EED materials have been found. These includes various amines commonly found in curatives for adhesive resins and common solvents.
Of note is that THPP is not as thermally stable as other common pyrotechnics encountered at Pac Sci. Long term exposure at high temperatures (>250 °C) may alter the titanium/hydride ratio which changes the safety and output properties as well as the service life of components containing the composition.
Cleanup of minor spills should be done with a 50% IPA/DI water mix and a wet paper towel for blotting. Like other EM’s, major spills require evacuation of the area.