Ammonium perchlorate

About: Ammonium perchlorate is a research topic. Over the lifetime, 2359 publications have been published within this topic receiving 33412 citations. The topic is also known as: AP.

Preparation of Cu/CNT Composite Particles and Catalytic Performance on Thermal Decomposition of Ammonium Perchlorate

Abstract: Composite particles of carbon nanotubes (CNTs) and Cu were prepared by a chemical reduction method. Characterization of Cu/CNT composite particles was performed by TEM, SEM, FT-IR, XRD, XPS, AAS, DTA and EDS. The results show that the surface of CNTs is covered by Cu particles, and that the diameter of Cu/CNT composite particles gets larger than that of CNTs. Furthermore, in the presence of Cu/CNT composite particles, the peak temperature of the high-temperature decomposition of ammonium perchlorate (AP) decreased by 126.3 °C, and the peak of the low-temperature decomposition disappeared. Compared with a sample of simply mixed Cu and CNTs, the peak temperature of the high-temperature decomposition of AP-Cu/CNTs composite particles decreased by 11.4 °C. Compared with Cu, the peak temperature of the high-temperature decomposition of AP-Cu/CNT composite particles decreased by 20.9 °C. This work shows that the catalytic performance of Cu on the thermal decomposition of AP can be improved by compounding with CNTs.

Kinetic study of the reaction between hydroxyl-terminated polybutadiene and isophorone diisocyanate in bulk by quantitative FTIR spectroscopy

Abstract: A kinetic study of the reaction between a hydroxyl-terminated polybuta-diene (HTPB) and isophorone diisocyanate (IPDI) was carried out in the bulk stateby using quantitative Fourier transform infrared (FTIR) spectroscopy. The reaction isshown to obey a second-order rate law, being first order in both the HTPB and IPDIconcentrations. The activation parameters obtained from the evaluation of kinetic dataare D H ‡ †41.1 {0.4 kJ mol, D S ‡ †0198 {2JK 01 mol 01 and E a †43.8 {0.4 kJ mol 01 ,which are quite different from the solution values. However, they are in agreement withthe results obtained on propellants by torsional braid measurements. The large nega-tive value of the activation entropy is indicative of an associative mechanism, whichis in accord with the second-order rate law for the polyurethane formation. q 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1979–1983, 1997 Key words: HTPB; IPDI; diisocyanate; kinetics; polyurethane; FTIR spectroscopy INTRODUCTION other binders, such as poly(vinyl chloride). Fur-thermore, the low viscosity of HTPB facilitatesComposite propellants based on hydroxyl-termi- high solid loading in both fuel and oxidizer of thenated polybutadiene (HTPB) have become the propellant. At the final stage of a composite pro-workhorse propellants in present day solid rocket pellant preparation, a curing agent, usually a di-motors. Crystalline ammonium perchlorate (AP) isocyanate, is added to the heterogeneous mixtureand fine aluminum powder are used as oxidizer containing the prepolymer, fuel, oxidizer, andandmetallicfuel, respectively,intheHTPB-based other ingredients. The prepolymer and diisocya-composite rocket propellants. The solid loading, nate react with each other to form the polyure-which contributes to the rheological properties thane network [eq. (1)],which holds the fuel andand therefore affects the processability and me- oxidizerparticulates ina compositematrix havingchanical properties of the propellants, is largely mechanical and ballistic properties suitable fordetermined by the extent of polyurethane forma- rocket applications.tion. In this respect, the binder used in the propel-lant plays an important role. The polybutadienechain, in general, gives higher energy value andO'H 1 OCN O'C'N (1)better mechanical properties compared to the OHThe cure reaction of HTPB with diisocyanate hasbeen found to follow the second-order rate law.

Size and Shape of Ammonium Perchlorate and their Influence on Properties of Composite Propellant

Abstract: Most of the composite propellant compositions contain solid loading up to 86 per cent. The main solid ingredients of composite propellant are ammonium perchlorate (AP) and aluminium powder. Therefore, it is a must to characterise these to improve processibility and quality of composite propellant. Effect of particle size on propellants slurry viscosity and ballistic parameters are well documented, however, the effect of oxidizer particle shape is not reported. In the present study, different methods for size and shape characterisation are discussed and effect of size and shape of AP on composite propellant properties are studied. The data indicate that as size of AP decreases, propellant slurry viscosity increases and burn rate increases. The particles having higher shape factor provides less endof mix (EOM) viscosity of propellant slurry and burn rate. Further, effect of size of ground AP on shape is also investigated. From the data thus obtained, it is inferred that as size of ground AP decreases, shape factor decreases, and particles become more irregular in shape.Defence Science Journal, 2009, 59(3), pp.294-299, DOI:http://dx.doi.org/10.14429/dsj.59.1523