Poly-BAMO

The energetic nature of the azido group makes its incorporation into energetic polymers and binders very desirable. 3,3-Bis(azidomethyl)oxetane (BAMO) (28) and 3-azidomethyl-3-methyloxetane (AMMO) (33) are energetic monomers which on polymerization result in the energetic polymers poly[BAMO] (32) and Poly[AMMO] (34), respectively, both of which are under evaluation as potential energetic alternatives to HTPB in composite propellant formulations. ... 

There are a number of inert binders such as polyester, epoxy, polysulfide, polyurethane which have been reported as binders for composite propellants and plastic bonded explosives (PBXs). At present, hydroxy-terminated polybutadiene (HTPB) is regarded as the state-of-the-art workhorse binder for such applications. However, the recent trend is to use energetic binders such as poly [3,3-bis(azidomethyl oxetane)] [poly(BAMO)], poly (3-azidomethyl-3-methyl oxetane) [poly(AMMO)], PNP, GAP diol and triol, nitrated HTPB(NHTPB), poly(NiMMO), poly(GlyN) and nitrated cyclodextrin polymers poly(CDN) for PBXs and composite propellants in order to get better performance. 

The synthesis of AMO involves treatment of 3,3-bis(chloromethyl) oxetane (BCMO) with sodium azide in the DMF medium at 85 °C for 24 h. Similarly, AMMO which is a monofunctional analog of AMO is synthesized by the azidation of chloro/tosylate product of 3-hydroxymethyl-3-methyl oxetane (HyMMO) with sodium azide in DMF medium at elevated temperatures. These energetic monomers are readily polymerized to liquid curable prepolymers with the help of boron trifluoride etherate/l,4-butanediol initiator system and the outlines of synthesis [147-150] of poly(BAMO) [Structure... 

BAMO is perhaps the most prominent among the azido oxetanes class in terms of the number of polymers and copolymers reported so far. Due to its symmetrical azido groups, it assumes special significance as a hard block repeating unit in a thermoplastic elastomer. However, the homopolymer is solid and cannot be used directly for binder applications because of its crystal-tine nature. Also, poly(BAMO) shows relatively poor mechanical properties as a binder for solid rocket propellants [153]. Many copolymers of BAMO with non-energetic co-monomers tike tetrahydrofuran (THF) have been reported. The BAMO-THF copolymer is an excellent candidate for binder applications with its energetic BAMO content coupled with the THF block which affords... 

Structure (4.22) BAMO-TFIF Copolymer Scheme 4.5 Synthesis of poly(BAMO) and BAMO-THF copolymer. 

Development of an oxetane binder, poly(BAMO/AMMO) as an insensitive propellant binder. Proc. ADPA Inti. Symp. on Energetic Materials Technology, 1994, Orlando, Florida. 

As discussed under explosives and propellants, a number of energetic binders GAP, NHTPB, poly(NiMMO), poly(GlyN), poly(BAMO), poly(AMMO) and BAMO-AMMO copolymers etc. have been reported in the recent past and are at various stages of development and introduction for bulk production of explosives and propellants for various applications. These polymeric binders are reasonably stable and are of established compatibility with a wide range of ingredients used for explosive and propellant formulations. The data on their explosive properties impact, friction and electric spark sensitivities, indicate that it is safe to handle these materials. However, there appears to be no report in the open literature on... 

Poly-BAMO is synthesized via cationic polymerisation from the monomer 3,3-bis(azidomethyl)l-oxetane (BAMO). The polymerisation reaction is quenched with water to get polymer chains with hydroxyl endgroups which enable to react these pre-polymers later with isocyanate for curing reaction. Poly-BAMO has one of the highest nitrogen content of the - energetic binder components and is suggested for composite propellants. It is in the scope of actual research. 

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