Novel nitrogen-rich energetic macromolecules based on 3,6-dihydrazinyl-1,2,4,5-tetrazine

Abstract

Nitrogen-rich energetic macromolecules were synthesized by reacting dihydrazinyl-1,2,4,5-tetrazine (DHTz) with various diisocyanates. It has been shown that polymerization or cyclization reactions could take place depending on solvent systems and reaction conditions. The formed macrocycles and polymers were comprehensively characterized by IR, NMR, high resolution MS and SEM, while the thermal stability was studied by DSC. The energetic properties of our new compounds were investigated by bomb calorimetry, along with calculations using the EXPLO-5 code. It was found that macrocycle C-DHTZ-TM and corresponding polymer P-DHTZ-TM prepared on a basis of DHTZ and tetramethylene diisocyanate have larger heats of combustion than RDX, GAP and polyGLYN. C-DHTZ-TM has a comparable density and larger detonation velocity than TNT. The nitrogen content of C-DHTZ-TM and P-DHTZ-TM is larger than 47%. The thermal stability of DHTz-based energetic macromolecules was found to be higher than currently used energetic polymers including GAP, polyNIMMO and polyGLYN.The ADN based compositions bonded by 60% (by weight) of P-DHTZ-HM and P-DHTZ-MB polymers have higher theoretical specific impulse than that bonded by polyGLYN. Therefore, our new compounds could be promising ingredients as energetic binders or fillers. Moreover, all of the macrocycles have potential to be used as energetic gelators in gel propellants.

2,3,5,6-Tetra(1H-tetrazol-5-yl)pyrazine: A Thermally Stable Nitrogen-Rich Energetic Material

“…In an effort to create evermore powerful and effective EMs, researchers use different strategies to increase the energy content of the desired molecule. , The foremost challenge in the development of EMs is the combination of targeted performance properties with chemical and mechanical stability, features that tend to be counterproductive (e.g., the higher the energy content of the molecule the lower the thermal stability and/or higher the sensitivity toward external stimuli) . One of the most promising approaches toward powerful EMs is carefully designed synthesis of high-nitrogen-content molecules (e.g., 1,2,4,5-tetrazines − 3,3′-azobis­(6-amino-1,2,4,5-tetrazine) , and tetrazoles − 5,5′-bistetrazole; Chart ). The significant differences in the bond energies for singly (160 kJ mol –1 ), doubly (418 kJ mol –1 ), and triply (954 kJ mol –1 ) bonded nitrogen atoms, as well as their strength, enable nitrogen-rich molecules to store relatively large amounts of energy which can be released upon its decomposition .…”

Emergence of Three Dimensional Printed Cardiac Tissue: Opportunities and Challenges in Cardiovascular Diseases

“…Various bio-degradable poly(urethane)s analogues made from aromatic isocyanate have been previously reported [ 83 ]. Aliphatic analogues like 1,4-diisocyanatobutane and 1,6-diisocyanato hexane are prepared and used instead of aromatic isocyanate, but they come with the drawback of crystallisation [ 84 , 85 ]. Their approach was successful in synthesising nontoxic, biodegradable, non-crystalline poly(urethane)s that can be fabricated into a 3D scaffold.…”