Effect of Nitrate Ester on the Combustion Characteristics of PET/HMX -based Propellants

Abstract

INTRODUCTIONEthylene oxide-tetrahydrofuran copolyether (PET), as a polymer binder and cyclotetramethylenetetranitramine (HMX) as an oxidiser are the major components of nitrate ester plasticised polyether (NEPE) propellants. Over the past several years, advances in energetic materials have been made in many types of propellant ingredients, including binders, oxidisers, and metal additives. Numerous literatures studies describe how to decrease the burning rate pressure exponent of NEPE propellants or how to enhance its combustion performance [1][2][3] . However, few data are available regarding the effect of nitrate ester nitroglycerine/triethylene glycol dinitrate (NG/TEGDN) on combustion characteristics of propellants, so the present paper is efforts to increase our knowledge in interpreting the combustion characteristics of PET/HMX-based propellants with different NG/TEGDN contents.Plasticiser is a key ingredient of high-energetic solid propellant and plays a vital role in controlling the solid propellant property. Extensive studies for plasticiser concentrate on thermodynamic, structural, mechanical, ballistic implication and sensitivity in high energy propellant [4][5][6][7][8] . Literature survey reveals that few studies have been conducted on the effect of nitrate ester NG/TEGDN on the combustion characteristics of PET/HMX-based propellants.The primary objective of this study is to characterise and compare the combustion behaviour of PET/HMX based solid propellants with different NG/TEGDN contents. It is hoped that this work would be useful in providing a clearer understanding of high performance energetic solid propellant studies. EXPERIMENTAL 2.1 Propellant FormulationsThe propellant samples (E-1 and E-2) investigated in this study consist of HMX particles with PET as a binder and NG/TEGDN as plasticisers. The particle size of HMX is 5-80 μm. Their main compositions are shown in Table 1. Effect of Nitrate Ester on the Combustion Characteristics of PET/HMX-based Propellants ABSTRACTThe effect of nitrate ester NG/TEGDN on the combustion characteristics of PET/HMX-based propellants has been experimentally investigated using of high-speed photography technique and scanning electron microscopy. It is indicated that the increase of NG/TEGDN content has little impact on the propellant burning rates at the same pressure. Furthermore, propellant can not be self-sustaining combustion at low pressure (≤1 MPa). The increase of NG/TEGDN content does not affect the flame structure of propellant, but it plays an important role in condensed phase reaction zone. The flame structure of propellant is estimated. The thermal decomposition products in different combustion zones are also discussed. Scanning electron microscopy examination of quenched sample indicates that a liquified layer forms during combustion of these propellants. Numerous gas bubbles are present. Especially, the burning surface of propellant with low NG/TEGDN content shows signs of crystallization. The thickness of condensed phase reaction zone, by cross...

Synergistic Catalytic Effect of a Series of Energetic Coordination Compounds based on Tetrazole‐1‐acetic Acid on Thermal Decomposition of HMX

“…Ammonium perchlorate (AP), cyclotrimethylene trinitramine (RDX), and cyclotetramethylene tetranitramine (HMX) are the main ingredients in solid propellants, and hence their thermal decomposition characteristics directly influence the combustion performance of the solid propellants . Energetic coordination compounds used as the catalysts/additives to the propellants have attracted tremendous interests for such compounds not only contain more N=N or C=N groups, which hold a higher positive enthalpy formation but also provide fresh metal or metal oxide at the molecule level on the propellant surface, which could improve combustion performance when the compounds are used as the catalysts/additives to the propellants .…”