Propellants Explosives Pyrotechnics, Vol.42, No.3, 268-274, 2017
Synthesis, Characterization and Properties of Nitropolybutadiene as Energetic Plasticizer for NHTPB Binder
The nitration of low molecular weight polybutadiene (PB) by a convenient and inexpensive procedure was investigated. To retain the unique physico-chemical properties of the plasticizer, it was nitrated to an extent of 10% double bonds. The product nitropolybutadiene (NPB) was characterized by FT-IR and 1H NMR spectroscopy as well as GPC, DSC, and TGA methods. The kinetic parameters for the decomposition of NPB from room temperature to 4008C were obtained from non-isothermal DSC. The changes in glass transition temperature (Tg) and inert uncured binder systems were used for determination of its ef-ficiency as plasticizer. NPB was used in cured and unfilled nitro-hydroxyl terminated polybutadiene (NHTPB) binder. Isothermal thermogravimetric analysis (Iso-TGA) was employed to determine the migration rate in cured and unfilled HTPB binder systems compared to the dioctyladiphate (DOA) plasticizer. It was found that the exudation of the NPB plasticizer is slower than that of the DOA plasticizer. Thus, the NHTPB/ NPB binder system (binder/ plasticizer) presents more convenient mechanical properties than HTPB/ DOA and is a promising new energetic binder system for polymer bonded explosives.
Keywords:Nitropolybutadiene (NPB);Energetic polymer plasticizer;Glass transition temperature;Kinetic parameters;Plasticizer efficiency;Exudation