A Review of Improvement of Mechanical Properties of XLDB or NEPE Propellants Using NPBA Binder

Crosslinked double-base (XLDB) or Nitrate ester-polyether binder (NEPE) propellants including high level of fillers are capable of producing highest specific impulse (Isp)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. However incorporation of considerable amount of solid energetic materials, poor mechanical properties and dewetting is important problems in these propellants. These problems have 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 was introduced, its synthesize method and performance machanism in XLDB or NEPE propellants was well described. Then stress-strain curves for improved propellants containing NPBA or coated filler illustrated and discussed.