In the present study, the viscoelastic response of three composite solid propellants based on hydroxyl-terminated poly(butadiene), ammonium perchlorate and aluminum has been investigated. The investigation was surveyed by dynamic mechanical analysis over a wide range of temperatures and frequencies. The mechanical properties of these materials are related to the macromolecular structure of the binder as well as to the content and nature of solid fillers. The storage modulus, loss modulus, loss factor and glass transition temperature for each propellant sample have been evaluated. The master curves of storage (log G' vs log ?) and loss modulus (log G'' vs log ?) were generated for each propellant. A comparison of logaT vs temperature curves for all propellants indicate conformance to Williams-Landel-Ferry equation. Choosing the glass transition as the reference temperature, WLF equation constants are determined. Fractional free volume at the glass transition temperature and thermal coefficient of free volume expansion values are in accordance with the consideration that Al is reinforcing filler.

1,4-butanediol, as a chain extender, was incorporated into a hydroxyl-terminated poly(butadiene) based composite rocket propellant binder composition. As curing agents, isophorone diisocyanate (IPDI) and toluene diisocyanate (TDI) were used. Composite propellant binder network and mechanical properties, influenced by a presence of 1,4-butanediol, were examined. Network characteristics, sol-gel content and crosslink density have been calculated and successfully correlated to the mechanical uniaxial tensile properties of the tested propellant binders. Differential scanning calorimetry studies showed that 1,4-butanediol content did not influence the glass transition temperature, however the uniaxial tensile properties were shown to be a function of the crosslink density

This paper shows the results of chemical compatibility of two types of propellants (NGB-051and NC-28) with two types of polymer materials (Polyamide 12 and Polymethylmetacrylate) by different test methods. Testing was performed using heat flow calorimetry, differential scanning calorimetry, the method of chemical analysis after aging and vacuum stability test method according to STANAG 4147. The heat flow curves of propellants, polymeric materials and their mixtures and the theoretical curves were determined. Produced energy was calculated and the values of relative and absolute compatibility were determined. Analysis of the exothermic peak of decomposition of propellants and its mixture with polymer materials was performed and the maximum difference in peak temperatures was calculated. The stabilizer content of the unheated propellants, the artificially aged propellants and the propellants after heating in contact with the polymer material was determined. The values of the volume of released gas, by using vacuum stability test method, for the propellants and polymer materials as well as their mixtures were determined. The value of absolute compatibility was calculated. Compatibility was estimated on the basis of the results presented.

A suitable kinetic model for the consumption of stabilizer (diphenylamine) in single base gun propellants was investigated and successfully verified. The model assumes that a reaction of shifting order can be applied for the consumption of diphenylamine in single base gun propellants. It was found that the experimental data were well evaluated by a first-order reaction at high concentrations of diphenylamine in the propellant, but by a zero-order reaction at low concentrations during the final phase of the propellant life time. The mechanism of diphenylamine depletion was discussed with relation to the model and the ageing behavior of the propellants. The kinetic parameters of this model, which permit the calculation of the time up to complete consumption of the diphenylamine, were determined. The results were compared with the kinetic data obtained by a widely accepted model, which combines formally reactions of first and zero order, designated as an "exponential and linear" model. All comparisons gave satisfactory agreement.

The influence of tris(2,3-epoxypropyl)isocyanurate as a bonding agent on viscoelastic dynamic modulus of carboxylterminated (butadiene-co-acrylonitrile)-based composite propellant was investigated. Strain amplitude sweep tests have been run at the room temperature. Frequency dependencies of rheological behaviour parameters (storage and loss modulus) were also analyzed. Based on the frequency dependencies of the storage and loss modulus, in the temperature range from -80 °C to 40 °C, the master curves were created, reaching broader frequency interval in comparison to that used in the measurements. This enables a prediction of the material response at various frequencies, usually unobtainable experimentally. WilliamsLandell-Ferry (WLF) equation constants were determined for different reference temperatures. Further, material constants, fractional free volume at the glass transition temperature and thermal coefficient of free volume expansion were calculated. The data obtained from WLF analysis of the tested composite propellants showed that the values of the thermal coefficient of expansion of free volume and the fractional free volume at the glass transition temperature decrease with increasing content of tris(2,3-epoxypropyl)isocyanurate. Also, the apparent energy for viscoelastic relaxation increases, because of the increased intermolecular hydrogen interactions