Search

A series of glycidyl azide polymer (GAP) with hydroxyl-terminated poly(ethylene oxide-co-tetrahydrofuran) (P(EO-co-THF)) polymer networks of various functional molar ratios (R) and different GAP contents have been prepared through the step-wise curing process. The step-wise curing condition is determined based on the thermodynamic parameters of each simplex elastomer system, which is 45 °C-3d then 60 °C-4d. The mechanical properties of the elastomers have been improved from 1.88 to 2.11 MPa in W GAP = 50% under that condition, which is caused by the formation of the larger-sized mesh structure and in consequence the effective elastic strands increase. Meanwhile, the dynamic mechanical analysis (DMA) reveals that the glass transition temperatures of the elastomers are approximately −62.42 and −26.96 °C, respectively. Moreover, it can be concluded through DMA that the P(EO-co-THF) domains act as the main crosslinking joints compared with the GAP/N100 domains and thus cause the constrained effect. Combining extension test with DMA results, the network model of the elastomers is depicted. In addition, the thermal stabilities of the blending elastomers have also been studied, and their thermal stabilities meet the requirements of military materials.

Three kinds of bonding agent were chosen to improve the mechanical properties of GAP high-energy composite propellant based on GAP, BuNENA, HMX, AP, and Al. These bonding agents are N,N′-bis(2-hydroxyethyl) dimethylhydantoin and 1,3,5-trisubstituted isocyanurates (BA1), cyano-hydroxylated amines (BA2), and hyperbranched polyether with terminal groups substituted by hydroxyl, cyano and ester functional groups (BA3). To study the interaction between bonding agents and oxidizers, the effect of coating by bonding agents on the characteristic absorption peaks of AP and HMX were first studied by infrared spectroscopy. Then the effect of bonding agents on the adhesion work between oxidizers and binder system were determined. The results showed that BA2 has the strongest interaction with AP, whereas BA1 and BA3 have relatively strong interaction with HMX. The AP grain coated by BA2 has the strongest adhesion work to the binder system, and there is not much difference in the values of adhesion work towards binder system of three coated HMX grains. At last the three bonding agents were added to GAP propellant, which has a theoretical specific impulse of 276.03 s. When the three kinds of bonding agent was used alone, the sense of “dewetting” in propellant was relieved but still existed. The combination of BA2 to BA1 or BA3 improved the adhesions between oxidizers and binder system effectively, and the mechanical properties of GAP propellant reached to δm=0.69 MPa, ϵb=32.7 %.

The graphene/Fe2O3 nanocomposites were prepared by the sol–gel method and then dried naturally in air or supercritical CO2. X-ray diffraction, scanning electron microscopy and specific surface area analysis were used to characterize the structure of the nanocomposites. The nanocomposites dried with supercritical CO2 have larger specific area and porous structure. The catalytic properties of the graphene/Fe2O3 nanocomposites for ammonium perchlorate were investigated by differential scanning calorimetry. When the nanocomposites were added, not only the thermal decomposition temperature of ammonium perchlorate was decreased, but also the exothermic heat was increased. Comparing the two drying methods, the graphene/Fe2O3 nanocomposites dried with supercritical CO2 showed better catalytic effects.

A kind of bonding functional energetic thermoplastic elastomers (ETPEs) were synthesized as the binder of solid propellants using the mixture of chain extenders including diethyl bis(hydroxymethyl) malonate (DBM). The results showed that the mechanical properties of ETPEs decreased with increasing percent of DBM in the chain extenders. On the contrary, the work of adhesion between solid ingredients hexogen (RDX) and ETPEs increased. In order to test the comprehensive impacts of two elements, the RDX/ETPE propellants were prepared. The results showed when the percent of DBM was 25%, the overall properties of the propellants were optimum.

We report a simple and effective approach to fabricate graphene/nickel (G/Ni) aerogels by a sol–gel method and supercritical CO2 drying technique. The crystalline structure and chemical composition of the G/Ni aerogels have been investigated using X-ray diffraction and X-ray photoelectron spectroscopy. The morphology and porous attributes of the G/Ni aerogels have been characterized by transmission electron microscopy, scanning electron microscopy and nitrogen adsorption tests. Results indicate that the resulting aerogels, in which the Ni nanoparticles are dispersed on the graphene sheets, exhibit mesoporous structure and large surface areas. The catalysis effect of the G/Ni aerogels on the thermal decomposition of ammonium perchlorate was studied by differential scanning calorimetry. When 9 wt% of the aerogels was added, the thermal decomposition temperature of ammonium perchlorate was decreased by 122 °C. The results show that the G/Ni aerogels exhibit a remarkable catalytic performance for the thermal decomposition of ammonium perchlorate due to the combination of Ni nanoparticles and graphene sheets.

A new nano-composite energetic material, in which submicrometer ammonium perchlorate (AP) particles and nanoparticles of cyclotrimethylene trinitramine (RDX) were uniformly dispersed in the cross-linked nitrocellulose (NC), was prepared by the sol–gel method. The structure of the material was confirmed by means of SEM, XRD and N2 adsorption isotherm techniques, and the results showed that the NC/RDX/AP nano-composite energetic material is monolithic with numerous pores of nanometer scale and the mean grain size of RDX is

Hydroxyl-terminated polybutadiene (HTPB) propellant were prepared with different content of Al/B/Fe2O3 nano thermite, and the mechanical, thermal and energetic performances were studied. Al/B/Fe2O3 nano thermite exhibited good compatibility with HTPB and dioctyl sebacate (DOS) through differential scanning calorimetry (DSC) tests. Mechanical experiments show that the mechanical properties of HTPB propellant could be improved by the addition of a small quantity of Al/B/Fe2O3 nano thermite, compared with the absence of Al/B/Fe2O3 nano thermite. For example, with the addition of 3% Al/B/Fe2O3 nano thermite, the tensile strength and elongation of propellant had the increase of 15.3% and 32.1%, respectively. Thermal analysis indicated that the decomposition of ammonium perchlorate (AP) in HTPB propellant could be catalyzed by Al/B/Fe2O3 nano thermite, the high-temperature exothermic peak of AP was shifted to lower temperature by 70.8 °C when the content of Al/B/Fe2O3 nano thermite was 5%, and the heat released was enhanced by 70%. At the same time, the heat of explosion of HTPB propellant could also be enhanced by the addition of Al/B/Fe2O3 nano thermite. Copyright © 2016 BCREC GROUP. All rights reserved Received: 5th November 2015; Revised: 4th December 2015; Accepted: 30th December 2015How to Cite: Deng, J., Li, G., Shen, L., Luo, Y. (2016). Application of Al/B/Fe2O3 Nano Thermite in Composite Solid Propellant. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1): 109-114. (doi:10.9767/bcrec.11.1.432.109-114)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.432.109-114