| || Some Mechanistic Aspects of Hyperbolic Ignition: Reaction of dinitrogen Tetroxide with Solid Amines and their Mixtures with Magnesium
Author : Jain, Sampat R. ;Vittal, Jagadese J. ;Mimani, Tanu
Source : Defence Science Journal ; Vol:42(1) ; 1992 ; pp 5-12
Subject : 662.3 Propellants;66 Chemical Technology
Keywords : Solid aromatic amines ;Dinitrogen tetroxide;Pre ignition reaction
Abstract : Ignition behaviour of various solid aromatic amines has been examined with dinitrogen tetroxide (N/sub 2/O/sub 4/), white and red fuming nitric acid, as oxidisers. p-toluidine and p-anisidine have been found to ignite spontaneously on coming into contact with N/sub 2/O/sub 4/. Other amines, particularly, those with an electron withdrawing substituents, do not ignite with either of the oxidisers. On mixing with magnesium powder, however, all the amines examined ignite readily with N/sub 2/O/sub 4/. An examination of the pre-ignition reaction products of p-toluidine and N/sub 2/O/sub 4/, shows the presence of p-toluidinium nitrate, 1,3-bis(p-tolyl)-triazene-1-oxide, p,p'-dimethylazobenzene and possibly a mixture of nitrated p-cresols. A probable pre-ignition reaction pathway involving the formation of nitrosamine intermediate has been proposed, which to certain extent, explains the synergistic ignition of amines and magnesium powder mixture with N/sub 2/O/sub 4/.
| || Interpenetrating Polymer Networks as Binders for Solid Composite Propellants
Author : Parthiban, S.;Raghunandan, B.N.;Jain, Sampat R.
Source : Defence Science Journal ; Vol:42(3) ; 1992 ; pp 147-156
Subject : 66 Chemical Technology;662.3 Propellants
Keywords : Poly methyl methacrylate;Burning rates
Abstract : A new family of polymeric binders for solid composite propellants is proposed, based on two component interpenetrating polymer networks (IPNs). These networks comprise two different polyurethanes based on hydroxy terminated polybutadiene and ISRO polyol interpenetrated with two different vinyl polymers, viz poly methyl methacrylate and polystyrene. the networks synthesized by the simultaneous interpenetrating technique have been characterized for their properties, such as stress-strain, density, viscosity, thermal degradation, and heat of combustion. Phase morphologies have been determined using electron microscopy. Suitable explanations have been adduced to rationalize the properties of IPNs in terms of their structures and chain interactions. A study of the mechanical properties and burning rates of the ammonium perchlorate (AP)-based solid propellant using the newly synthesised IPNs as binders, has been carried out. The results show that both mechanical strength and burning rate of solid propellants could be suitably modified by simply changing the nature and/or the ratio of the two interpenetrating polymer components.