Tomasz Gołofit

Thermal decomposition properties and compatibility of CL-20 with binders HTPB, PBAN, GAP and polyNIMMO

The compatibility of filler 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) with rocket propellant binders: hydroxyl-terminated polybutadiene (HTPB), butadiene-acrylonitrile-acrylic acid terpolymer (PBAN), glycidyl azide polymer (GAP) and poly(3-nitratomethyl-3-methyloxetane) (polyNIMMO), has been examined. The compatibility of the compounds has been tested in accordance with the STANAG 4147 standard and its modification consisting in the change of the heating rate. As it arises from STANAG 4147 standard criterion, CL-20 is not compatible with polyNIMMO, PBAN and GAP and possibly incompatible with HTPB. Changes of relative position of peaks between measurements performed in hermetical pans and pans with a pinhole and with different heating rate were observed. In case of polyNIMMO and HTPB, changes of measurement parameters lead to estimated compatibility change. The analysis of the thermal decomposition of CL-20 revealed that it is a two-phase process. The first phase is associated with decomposition in solid phase; the second phase is associated with decomposition of volatile intermediate products of CL-20 decomposition. Due to the complex process of decomposition of tested samples, the apparent activation energy was used for the assessment of the compatibility. The apparent activation energy of the initial phase of decomposition CL-20 and its mixtures with binders are compatible with one another within the limits of measurement error. Results of measurement of apparent activation energy do not indicate a destabilizing effect of binders on the initial phase of decomposition of CL-20.

4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,903,11]dodecane Synthesis

4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,903,11]dodecane (TEX) was obtained by nitrolysis of 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine reaction using a mixture of fuming nitric acid and concentrated sulfuric acid. The optimal process temperature was 54–56°C. The yield of the synthesis depends inter alia on the rate the reactants are introduced into the reaction medium and on the time of conditioning of the reaction mixture. A maximal yield of ca. 40% was achieved at the reactant addition time of 2 h and conditioning time of 2 h. None of the other nitrating mixtures examined proved superior to the conventional nitrating mixture. The product was examined by high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC) techniques and the results are reported.

Wood adhesive application of poly(hydroxyurethane)s synthesized with a dimethyl succinate-based amide backbone

Non-isocyanate poly(hydroxyurethane)s (PHUs) made by reacting bis(cyclic carbonate)s and amines are important alternatives to conventional polyurethanes. In this work, a series of PHUs was synthesized using a solvent-free, catalyst-free method from bis(2,3-dihydroxypropyl)ether dicarbonate and 1,3-diaminopropane using differing molar ratios of dimethyl succinate to change selected properties of each PHU. The obtained PHUs were characterized by FT-IR, 1H NMR and 13C NMR spectroscopy and their thermal properties and viscosities were determined. We report the use of the obtained PHUs as wood adhesives and the work of adhesion data determined using Owens–Wendt method. The mechanical properties (strength) of different PHU–wood joints were compared. It was found that the addition of dimethyl succinate increases the hydrophobicity of coatings by increasing the water contact angle and decreasing the polar component of the surface free energy of the PHU coatings. PHUs with urethane and amide backbones were stronger than those without.

Data on synthesis and characterization of new diglycerol based environmentally friendly non-isocyanate poly(hydroxyurethanes).

This article contains original experimental data, figures and methods to the preparation of non-isocyanate poly(hydroxyurethanes) by an environmentally friendly method without the use of toxic phosgene and isocyanates from bis(2,3-dihydroxypropyl)ether dicarbonate and various diamines (Tryznowski et al., Submitted for publication) [1]. Bis(2,3-dihydroxypropyl)ether dicarbonate was obtained from a one-step procedure from commercially available diglycerol. The product was characterized by 1H NMR, 13C NMR, and FTIR spectroscopies and for the first time by X-Ray diffraction measurements. Then, the bis(cyclic carbonate) monomer was used as a precursor for the synthesis of various NIPUs. The NIPUs were prepared in a non-solvent process. Spectral and thermal properties of the NIPUs are compered. Here we give the procedure in order to perform bis(2,3-dihydroxypropyl)ether dicarbonate with high yield and the procedure NIPU synthesis and the complete set of monomer and NIPU analysis (1H NMR, 13C NMR, FTIR, X-Ray).

Application and properties of aluminum in primary and secondary explosives

Aluminum is an easily available and cheap material, which is widely used in military and civil industries, e.g. in space technology, explosion welding, mining, production of oil and natural gas, manufacture of airbags. Primary and secondary explosives containing aluminum are described in this part of the work. Aluminum is added to high explosives of different shapes and sizes. These parameters influence inter alia detonation velocity (D), explosion heat, detonation pressure, pressure impulse and thermal stability. Detonation parameters of high explosive (HE) containing aluminum have been determined for binary systems consisting of high explosive or oxidizer and aluminum, plastic bonded explosives (PBX), melt cast explosives, thermobaric explosives (TBX), ammonium nitrate fuel oil (ANFO). Aluminum causes different effects on detonation velocity and explosion heat depending on the type of high explosive in binary systems. The dependence of the aluminum content in a mixture with ammonium nitrate with detonation velocity increased for an aluminum range from 0 to 10%, changed little between 10 and 16% of aluminum added and decreased from 16 to 40% of the aluminum content. For an aluminum content higher than 40%, the detonation process was not observed. The performance of explosives can be determined by the shock wave intensity. An increase in the pressure impulse made Al particle react with gaseous products and the air behind the front of detonation wave. The addition of aluminum also influences the thermal stability of high explosive materials.