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Research and development efforts for realizing higher performance levels of high energy materials (HEMs) are continued unabated all over the globe. Of late, it is becoming increasingly necessary to ensure that such materials are also eco-friendly. This has provided thrust to research in the area of force multiplying HEMs and compounds free from pollution causing components. Enhancement of the performance necessitates introduction of strained structure or increase in oxygen balance to achieve near stoichiometry. The search for environment friendly molecules is focused on chlorine free propellant compositions and lead free primary explosives. Energetic polymers offer added advantage of partitioning of energy and thus not necessitating the concentration of only solid components (HEMs and metal fuels) in the formulations, to achieve higher performance, thereby leading to improvement in energetics without adversely affecting the processability and mechanical properties. During recent times, research in the area of insensitive explosives has received impetus particularly with the signature of STANAG. This paper gives a review of the all-round advances in the areas of HEMs encompassing oxidizers, high-energy dense materials, insensitive high-energy materials, polymers and plasticizers. Selected formulations based on these materials are also included.

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Enhanced performance of propellants and explosives is the most sought-after attribute for ambitious research programs in the field of high energy materials. Convergence of defence and space sector priorities has always kept research and development efforts in the area of propellants to the forefront. With the diminishing boundaries between rocket and gun propellants, as well as explosives, the possibility of low-vulnerable munitions with high performance potentials and spin-off advantages of research on rocket propellants are also emerging on the forefront. At the same time, an increasing predominance of missiles in today's military warfare, as well as the space sector, has brought the issue of pollution by chlorine-containing combustion products of modern ammonium-perchlorate-based propellants into focus. A drastic transformation of high energy material technology is in offing. Research and development efforts made in this direction have brought an array of new materials into prominence. This paper reviews the recent work done in the frontier areas of advanced novel high energy materials. This paper covers the global scenario in the development of oxidizers, binders, plasticizers, high energy density materials, and insensitive high energy materials.Key words: high energy materials, ADN, CL-20, double-base propellants. GLOBAL SCENARIOThe unprecedented demand for long-range and high-payload-capability missiles during the later part of the 20th century catapulted developmental programs on composite (CP) and composite modified doublebase (CMDB) propellants to the premier position, relegating the classical double-base (DB) propellant systems to a secondary role. Both these systems offer a much superior specific impulse (250-260 sec) as compared with double-base propellants (220-230 sec). Composite propellants comprising ammonium perchlorate (oxidizer) and aluminum (metal fuel) dispersed in a hydroxyl-terminated polybutadiene (HTPB) binder have emerged as the major propellant systems for missiles and space vehicles all over the globe, while the CMDB propellant system finds application in tactical missiles. CMDB propellant consists of ammonium perchlorate (AP) and aluminum dispersed in a nitrocellulose (NC) and nitroglycerin (NG) double-base matrix as a binder. Composite propellants have advantages over CMDB propellants, particularly for the case-bonded applications, due to a superior strain (extension) capability of HTPB even at subzero temperatures as reflected by its glass-transition temperature of about −65 • C. These propellants are manufactured at SNPE (France) for missiles like PLUTON and HADES. The turnover of SNPE (France) has crossed the 350 million USD mark in the early 1990s as per the published reports in the International Defence Review. Thiokol (USA) and Royal Ordnance (UK) produce a wide range of composite propellants to meet the increasing demand of US and UK's defence and space programs [1][2][3][4][5].The last few decades have witnessed a resurgence of interest in ramjet and scramjet technologies due...