Nitramine-Group-Containing Energetic Prepolymer: Synthesis, and Its Properties as a Binder for Propellant

Hwang Hwang,Min Min,Kim Kim,Jung Jung,Mun Mun,Jeon Jeon,Cho Cho

doi:10.3390/polym11121966

Hwang Hwang, Min Min + Show 5 more

Open Access

https://doi.org/10.3390/polym11121966

Copy DOI

Abstract

A composite solid propellant which generates high propulsive force in a short time is typically composed of an oxidizer, a metal fuel powder and a binder. Among these, the binder is an important component. The binder maintains the mechanical properties of propellant grains and endures several thermal and mechanical stresses in the engine. Several studies have been reported for the development of energetic propellant binders for increasing the propellant′s propulsive force. While several materials have been studied for the synthesis of energetic prepolymers, a nitramine-group-containing prepolymer is a suitable candidate because these types of prepolymers are less toxic and more cost-effective when compared to the traditional glycidyl azide polymers (GAP) and triazole-based prepolymers. Considering the lack of studies for the binder using a nitramine-group-containing prepolymers, we synthesized a nitramine-group-containing monomer and polymerized a nitramine-group-containing prepolymer. The prepolymer was then used for the preparation of the binder and its thermal and mechanical properties, as well as the effect of the plasticizer, were studied. The binder that was prepared using the prepolymer containing a nitramine-group showed very high elongation, tensile strength. Nitrate-ester (NE)-type plasticizer could reduce the glassy transition temperature (Tg)of the binder successfully. Also, high-energy is released due to the decomposition of the nitramine-group at around 245 °C, thus exhibiting the efficiency of the nitramine-group-containing prepolymer as an excellent energetic binder material.

Highlights

The 20th-century world wars and competitive international space exploration have contributed extensively to the development of rocket propellants, which have been continually studied for development of the aerospace industry and long-range missiles
The purpose of this study was to investigate the effect of a nitramine group present in the polymer backbone on the properties of the binder for the propellant
The experimental conditions for the synthesis of the energetic monomer containing the nitramine group were established and the monomer was used for the polymerization of a polyester-type nitramine-containing prepolymer with a terminal –OH group

Summary

Introduction

The 20th-century world wars and competitive international space exploration have contributed extensively to the development of rocket propellants, which have been continually studied for development of the aerospace industry and long-range missiles. Propellants are classified as liquid and solid propellants according to their phase. Liquid-fuel engines, which use liquid propellant, typically have complex structures which restrict their size. Solid propellants are widely used because they allow the design of variable size fuel engines [1]. Among the various types of solid propellants available, the composite-solid propellant started with a polysulfide binder by Thiokol in the 1950s in the United States, is easy to store and can generate high propulsive force in a short time.

Objectives

Results

Conclusion