New Energetic Binder Synthesis Study

Energetic binder can be used as the important component in polymer-bonded explosives(PBXs),which influences PBXs' detonation energy and safety,and has a properous perspective in the applications of propellants and explosives.This paper investigated the synthesis methods of the three energetic binders poly(glycidyl nitrate)(PGN),poly(3,3-bis(azidomethyl) oxetane)(PBAMO) and glycidyl azide-r-bis(azidomethyl)oxetane copolymer(BAMO-GAP).By using 2-(chloromethyl) oxirane(ECH) and propane-1,2,3-triol as starting materials,respectively,PBAMO was synthesized through the polymerization of monomer glycidyl nitrate(GN).Then we prepared PBAMO through the ring-opening polymerization of BAMO by employing 2-bis(bromomethyl)propane-1,3-diol(TBMHMM) as starting material.Based on the synthesis of PBAMO,we synthesized BAMO-GAP through the proper copolymerization of PBAMO (hard-segment) and glycidyl azide polymer(GAP)(soft-segment).Furthermore,we detailedly discussed such technical conditions as starting materials,solvents,initiators,molar-ratio of raw materials,reacting time and temperature employed in the synthesis routes.The molecule structures for products were characterized by IR,^H NMR,and ¹³C NMR, the crystallinity characterized by X-ray diffraction(XRD),and the superficial configuration observed by scanning electron microscope(SEM).It is concluded that the three polymers are all linear configuration,PBAMO and BAMO-GAP are partly crystallized.Especially the crystallinity increases,with the increase of the molar-ratio of soft segment.As a result,the thermolplastic elastomers with the molar ratio of BAMO:GAP being 1:1 and 2:1 are properly suitable for practical application owing to their relatively better plasticity.We also studied the thermal decomposition property of synthesized energetic polymers using differential scanning calorimetry(DSC) and thermogravimetry analysis(TGA) etc. methods.The TG results show that PGN,PBAMO and BAMO-GAP are stable before 150℃, 200℃,and 230℃,respectively.The apparent activation energy for PGN by the Kissinger method is 182.0 kJ·mol^-1,being 22.2 k·Jomol^-1 higher than that of RDX,and it for PBAMO is 156.2 kJ·mol^-1,aprroaching that of RDX,which illustrates both of them have good thermal stablity.And under the heating rate of 10℃.min^-1,the thermal decomposition temperature of BAMO-GAP decreases with the molar-ratio of soft-segment increasing.