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.
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.
TEX is a thermostable compound and less sensitive to external stimuli. It sublimates and decomposes at high temperature. The influence of DSC and TG measurement conditions and substance mass on the thermal decomposition of TEX was determined. It was observed that substance mass, pan type and fulfillment degree of pan influence the thermal decomposition and kinetic parameters of TEX decomposition. Sublimation of the sample was the main observed process; thermal decomposition was the secondary process during the heating of TEX in open pans. With increasing substance mass, the participation of thermal decomposition of TEX increased. Uncontrolled thermal decomposition was observed for larger mass of a sample. The sublimation and decomposition processes were confirmed by FT-IR method. Thermal decomposition was the main process observed during heating the sample of TEX in hermetic pans. Sublimation of a sample was marginal. The sublimation effect decreased with increasing the degree of fulfillment pan. The kinetic parameters were determined with the Friedman’s isoconversional method. The conversion, mass of sample and the type of pan caused the large changes in the values of kinetic parameters. The apparent activation energy varied from 128 to 355 kJ mol−1 and logA varied from 9.95 to 30.64 in initial step (α = 0.02) for different condition of measurements. The low values of apparent activation energy (about 130 kJ mol−1) were associated with sublimation process and the high values (about 340 kJ mol−1) with the decomposition process.