Properties of a fast-burning ballistic modifier coated by polyurethane and its effect on propellant combustion

The properties of fast-burning energetic compound ACP (a novel ballistic modifier for propellants) coated with polyurethane adhesive were studied by SEM, attenuated total reflection FTIR (ATR-FTIR), XPS and mechanical sensitivity apparatus. The results indicate that surface of coated ACP is covered with a layer of film, minute cracks decreased, and coating degree R is calculated and can be effectively controlled by regulating the contents of polyurethane adhesive in solution. Mechanical sensitivity experimental results indicate that the special height H₅₀ of coated ACP is determined as 63.1 cm, which increased by 22.4 cm than that without coating, and friction sensitivity of ACP is reduced from 48% to 28% after coating. Applying the coated ACP into composite modified double base (CMDB) propellant, the burning rate pressure exponent in the pressure range of 11-20.5 MPa is decreased by 0.3 than that by applying uncoated ACP with the same content in propellant. The mechanism of reduction in burning rate pressure exponent of CMDB propellant is theoretically investigated.