Bomb Calorimetric Correlation Study between Chemical Structure and Enthalpy of Formation for a Linear Energetic Polyphosphazene

• Autorzy: Bellamy A. J. , Contini A. E. , Golding P.
• Języki publikacji: EN

Abstrakty

EN

Energetic polyphosphazenes constitute a novel class of insensitive binders which potentially outperform conventional carbon-based systems in terms of their energy-densities and glass transition temperatures. To facilitate the calculation of energetic performance for these materials, we report here on the use of bomb calorimetry to determine the standard enthalpies of combustion (ΔcH°) and formation (ΔfH°) of 2,2,2-trifuoroethan-1-oxy-/2,3-dinitratopropan-1-oxy-polyphosphazene (I) as the proportion of (energetic) 2,3-dinitratopropan-1-oxy substituents (% Energetic Substitution, % ES) is varied between 31% and 78%. Similar data is presented for the parent polymer bis(2,2,2-trifuoroethan-1-oxy)-polyphosphazene (II) (% ES = 0). ΔcH° was found to vary between -2275 kJ·mol^-11for the parent polymer II (% ES = 0) and -3415 kJ·mol^-1 for I with % ES = 78. The corresponding values for ΔfH° were -3184 kJ·mol^-1 and -1566 kJ·mol-1. These data indicate that, as expected, the polymer heats of formation become more favourable – with respect to the energetic performance of the polymer – as the percentage of energetic side chain functionalities (% ES) increases.

Słowa kluczowe

EN

PBX technology; energetic polyphosphazenes; bomb calorimetry; enthalpy of combustion; enthalpy of formation

• Czasopismo: Central European Journal of Energetic Materials
• Rocznik: 2013
• Tom: Vol. 10, no. 1
• Strony: 3--15
• Opis fizyczny: Bibliogr. 19 poz., tab, wykr.

Twórcy

autor

Bellamy A. J.

• Cranfeld University, Defence Academy of the United Kingdom, Shrivenham, Swindon, UK

autor

Contini A. E.

• Cranfeld University, Defence Academy of the United Kingdom, Shrivenham, Swindon, UK

autor

Golding P.

• Materials Science Research Division, AWE Aldermaston, Reading, Berkshire, UK

Bibliografia

• [1] Golding P., Trussell S.J., Energetic Polyphosphazenes – a New Category of Binders for Energetic Formulations, National Defense Industrial Association 2004 Insensitive Munitions and Energetic Materials Technology Symposium, San Francisco, California, 15th-17th November; Golding P., Trussell S. J., Enhanced Energetic Polyphosphazenes, National Defense Industrial Association 2006 Insensitive Munitions and Energetic Materials Technology Symposium, Bristol, 24th-28th April.
• [2] Walters R.N., Hackett S.M., Lyon R.E., Heats of Combustion of High Temperature Polymers, Fire Mater., 2000, 24, 245-252.
• [3] Walters R.N., Molar Group Contributions to the Heat of Combustion, Fire Mater., 2002, 26(3), 131-145.
• [4] Girdhar H.L., Peerzada G.M., Handoo D., Specifc Enthalpies of Combustion of Some Acrylic Polymers, Fuel, 1985, 64(7), 1011-1013.
• [5] Ribeiro da Silva M.A.V., Cabral J.I.T., Experimental Study on the Thermochemistry of 5-Nitroindole and 5-Nitroindoline, J. Chem. Thermodyn., 2009, 41, 355-360.
• [6] Andruzzi F., Barnes D.S., Plesch P.H., Enthalpy of Polymerization of Endo-2-methyl-7-oxabicyclo[2.2.1]heptane, Makromol. Chem., 1975, 176(7), 2053-2057.
• [7] Sanden R., Determination of the Heat of Formation of Poly(dimethysiloxane), Int. Jahrestatung Fraunhofer – Institut Fuer Treib- und Explosivstoffe, 17th Anal. Prop. Explos. Chem. Phys. Methods, 1986, 65/1-65/13.
• [8] Desai H.J., Cunliffe A.V., Hamid J., Honey P.J., Stewart M.J., Amass A.J., Synthesis and Characterisation of α,ω-Hydroxy and Nitrato Telechelic Oligomers of 3,3-(Nitrato-methyl)methyl Oxetane (NIMMO) and Glycidyl Nitrate (GLYN), Polymer, 1996, 37(15), 3461-3469.
• [9] Diaz E., Brousseau P., Ampleman G., Prud’homme R.E., Heats of Combustion and Formation of New Energetic Thermoplastic Elastomers Based on GAP, PolyNIMMO and PolyGLYN, Propellants Explos. Pyrotech., 2003, 28(3), 101-106.
• [10] (a) Allcock H.R., Maher A.E., Ambler C.M., Side Group Exchange in Poly(organophosphazenes) with Fluoroalkoxy Substituents, Macromolecules, 2003, 36(15), 5566-5572; (b) Montague R.A., Matyjaszewski K., J. Am. Chem. Soc., 1990, 112(18), 6721-6729.
• [11] Golding P., Trussell S.J., Novel Energetic Polyphosphazenes Useful for Explosive Binding, Patent application 2006, WO 032882A-1.
• [12] Schmiddt R.D., Manser G.E., Heats of Formation of Energetic Oxetane Monomers and Polymers, 32nd Int. Annu. Conf. ICT, Karlshrue, Germany, 2001, 140-1 to 140-8.
• [13] Bellamy A.J., Contini A.E., Golding P., Oxygen Combustion Calorimetry of Samples Containing Phosphorus and Fluorine: Formation of Fluorinated Phosphoric Acids as Non-ideal Combustion Species, Combust. Sci. Technol., 2008, 180, 2103-2126.
• [14] Bellamy A.J., Contini A.E., Golding P., Trussell S.J., Bomb Calorimetric Study of a Series of Energetic Linear Polyphosphazenes, New Trends Res. Energ. Mater., Proc. Semin., 8th, Pardubice, Czech Republic, 2005, 134-141.
• [15] Experimental Thermochemistry, (Rossini F.D., Ed.), Interscience Publishers, New York, 1956.
• [16] Cox J.D., Wagman D.D., Medvedev V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corporation, New York, 1989.
• [17] Contini A.E., Calorimetric Investigations of a Series of Energetic Polyphosphazenes, PhD Thesis, Cranfeld University, 2005. Document available online at https://dspace.lib.cranfeld.ac.uk/handle/1826/2997.
• [18] Krech M., Price S.J.W., Yared W.F., Determination of the Heat of Formation of Octafuorotoluene and Calculation of D[C6F5-F] – D[C6F5-CF3], Can. J. Chem., 1973, 51(22), 3662-3664.
• [19] Krech M., Price S.J.W., Yared W.F., Determination of the Heat of Formation of Hexafuorobenzene, Can. J. Chem., 1972, 50(18), 2935-2938.