Improvement of mechanical properties in CMDB propellant by NPBA

Composite modified double base (CMDB) propellants are capable of producing highest specific mpulse (I-sp)with wide flexibility of burning rates among the solid rocket propellants and therefore are preferred over conventional double base and composite propellants in many applications. But because of incorporation of considerable a mount of solid energetic materials, poor mechanical properties and dewetting is an important problem in those propellants. This problem has been solved by addition of small amounts of neutral polymeric bonding agent (NPBA) or by coating of energetic fillers(e.g.RDX,AP....) with suitable materials. In this paper, NPBA were introduced, its synthesis method and performance machanism in CMDB propellant is well described. Then stress-strain curres for improved propellants containing NPBA or coated filler illustraded and discussed.