Noncrystalline Binder Based Composite Propellant

Mohamed Abdullah,A R Zarei,F Gholamian

doi:10.1155/2013/679710

Mohamed Abdullah, A R Zarei + Show 1 more

Open Access

https://doi.org/10.1155/2013/679710

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Abstract

This study reports on propellants based on cross-linked HTPE binder plasticized with butyl nitroxyethylnitramine (BuNENA) as energetic material and HP 4000D as noncrystalline prepolymer. This binder was conducted with solid loading in the 85%. The results showed an improvement in processability, mechanical properties and burning rate. In addition, its propellant delivers (about 6 seconds) higher performance (specific impulse) than the best existing composite solid rocket propellant. Thermal analyses have performed by (DSC, TGA). The thermal curves have showed a low glass transition temperature () of propellant samples, and there was no sign of binder polymer crystallization at low temperatures (−50°C). Due to its high molecular weight and unsymmetrical or random molecule distributions, the polyether (HP 4000D) has been enhanced the mechanical properties of propellants binder polymer over a large range of temperatures [−50, 50°C]. The propellants described in this paper have presented high volumetric specific impulse (>500 s·gr·cc−1). These factors combined make BuNENA based composite propellant a potentially attractive alternative for a number of missions demanding composite solid propellants.

Highlights

Much research on composite solid propellants has been performed over the past few decades and much progress has been made, yet many of the fundamental processes are still unknown, and the development of new propellants remains highly empirical
It has shown excellent mechanical properties especially at low temperatures (−40∘C) when binder elongation at maximum stress reached to 65–70%
We have believed that the withstanding properties refer to kind of prepolymer used and to the presence of butyl nitroxyethylnitramine (BuNENA) in composition

Summary

Introduction

Much research on composite solid propellants has been performed over the past few decades and much progress has been made, yet many of the fundamental processes are still unknown, and the development of new propellants remains highly empirical. A higher specific impulse (Isp) of composite propellants is obtained by incorporating a maximum possible amount of solids (oxidizer/metallic fuel) in the binder matrix and substituting the inert materials with energetic ones (energetic plasticizers). Present day applications demand propellants of superior mechanical properties in addition to higher energy content. Due to these contradictory requirements hydroxy-terminated polyether (HTPE) based propellants are plasticized with energetic plasticizers, such as BuNENA, bolster performance and mechanical properties [1]. A number of studies have been carried out in the past on the formulation, processing, and improvement of mechanical properties and ballistic evaluation of HTPE based composite propellants, but with inert plasticizers and using conventional polyether that can be crystallized at low temperatures [3]. Propellants based on cross-linked HTPE binders are being used as alternatives to HTPB compositions because they give a less severe response in slow cookoff tests for insensitive munitions (IM) compliance [8,9,10]

Experimental

Results and Discussion

Conclusions