HTPB is a translucent liquid with a color similar to wax paper and a viscosity similar to corn syrup. The properties cannot be precisely stated because HTPB is a mixture+ rather than a pure compound+, and it is manufactured to meet customers' specific requirements. An oligomeric unit typically consists of 5–10 butadiene molecules linked together, with each end of the chain terminated with a hydroxyl [OH] group. HTPB is usually cured by an addition reaction+ with a polyisocyanate+ compound.
A solid form is used in model rocketry as a high power fuel known commonly as RBS. It has also found its way into the pyrotechnics industry in mortar tubes for aerial-shell fireworks.
HTPB is used in many solid rocket+ motors to bind the fuel and oxidizing agent+ into a solid mass. For example, it is used in all 3/4 stages of the Japanese M-5 rocket+ satellite launchers and PSLV+ rocket developed by ISRO+ for satellite launches. JAXA+ describe the fuel as "HTPB/AP/Al=12/68/20" which means, proportioned by mass, HTPB 12% (binder and fuel), ammonium perchlorate+ 68% (oxidizer), and aluminium+ powder 20% (fuel).