Aging Behavior of ADN Solid Rocket Propellants and Their Glass-Rubber Transition Characteristics

Int J of Chemical Kinetics

Belkhiri

et al. 2022

Polyester (HTPS) based polyurethane (PU) elastomers were currently established to be effective binders for high-energy composites with improved performances. Conventional PU binders are mostly non-energetic materials, and consequently reduce the energy performance significantly. Nitrocellulose (NC), is an energetic polymer widely used as an ingredient in propellants, explosives, fireworks, and gas generators, it may be introduced in PU-based compositions to overcome their performance drawback. Kinetic parameters must be specified in order to build PU binders with the most convenient and appropriate features. Therefore, the cure kinetics of polyester based polyurethane binder systems were investigated by Fourier transform infrared spectroscopy (FT-IR) isothermal method.The polyester prepolymer (Desmophen R 1200) was cured with hexamethylene diisocyanate (HDI: Desmodur R N100) at various molar ratios (R [NCO]/[OH] = 0.6, 1, 1.25, and 1.5) and under different isothermal conditions (T = 60 • C, 80 • C, 100 • C, and 120 • C). In addition, the effect of the addition of nitrocellulose on the kinetics of polymerization of PU was investigated. The progression of the reaction was followed based on the decrease of the peak intensity of -NCO group at 2271 cm −1 as a function of the reaction time. The curing kinetic model and the apparent activation energy (E α ) were determined by the use of Kamal autocatalytic model and Friedman isoconversional method, respectively.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Investigation of the curing kinetics of polyurethane/nitrocellulose blends through FT‐IR measurements

Int J of Chemical Kinetics

Belkhiri

et al. 2022

“…The common formulations of composite solid propellants (CSPs) and polymer-bonded explosives (PBXs) contain polyurethane polymeric binders [1][2][3][4][5][6][7][8][9][10][11], which are essentially based on hydroxyl-terminated polybutadiene (HTPB) or glycidyl azide polymer (GAP), used as prepolymers [12][13][14][15][16]. During the last few decades, composite propellant compositions based on polyester prepolymer binder systems (HTPS) have been elaborated as potential substitutes for HTPB and GAP compounds [17][18][19][20]. In fact, polyester-based polyurethanes are considered as a potential binder for CSPs and PBXs formulations, because of their relatively lower glass-to-rubber transition temperature (T g ) compared to that of GAP.…”

Section: Introductionmentioning

confidence: 99%

“…In fact, polyester-based polyurethanes are considered as a potential binder for CSPs and PBXs formulations, because of their relatively lower glass-to-rubber transition temperature (T g ) compared to that of GAP. Additionally, HTPB-based binders showed some compatibility issue with ammonium dinitramide (ADN) [17,19,20], currently considered as one of the main promising candidates as a green oxidizer [21]. Besides, polyester based binders exhibited good compatibility with ADN [17,19,20].…”

Section: Introductionmentioning

confidence: 99%

“…Additionally, HTPB-based binders showed some compatibility issue with ammonium dinitramide (ADN) [17,19,20], currently considered as one of the main promising candidates as a green oxidizer [21]. Besides, polyester based binders exhibited good compatibility with ADN [17,19,20]. Additionally, in the formulations of solid composite propellants, which contain high explosives fillers such as RDX or HMX, a bonding agent is added and acts as "Bond Bridge" between crystalline particles and the elas-tomer binder.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Preparation and Characterization of Polyurethane/Nitrocellulose Blends as Binder for Composite Solid Propellants

Propellants Explo Pyrotec

Belkhiri

et al. 2021

Polyurethane (PU) elastomers are largely used in the field of high-energy composites such as composite solid propellants (CSPs) and high-energy polymer-bonded explosives (PBXs) due to their distinguished characteristics. Conventional PU binders are mostly non-energetic materials, and consequently reduce the energy performance significantly. Nitrocellulose (NC), is an energetic polymer widely used as an ingredient in propellants, explosives, fireworks, and gas generators, may be introduced in PUbased compositions to overcome their performance drawback. In this context, PU/NC polymer blends at different mass ratios were prepared in the present work using hydroxyl-terminated polyester prepolymer (Desmophen® 1200) and nitrocellulose (NC) by solution blending process. The physico-chemical structure of the prepared PU/NC polymer composites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and density measurements. The thermal decomposition behavior was investigated by differential scanning calorimetry (DSC). Based on the obtained DSC results, the Arrhenius parameters were computed by different isoconversional kinetic approaches, namely, iterative Kissinger-Akahira-Sunose (It-KAS), iterative Flynn-Wall-Ozawa (It-FWO) and Vyazovkin's nonlinear integral method coupled with compensation effect (VYA/CE). Additionally, in order to highlight the influence of the introduction of the NC to the binder composition on the performance of a composite propellant, the theoretical performances, namely, theoretical specific impulse, the adiabatic flame temperature, as well as the ideal exhaust gaseous species were determined based on NASA Lewis Code, Chemical Equilibrium with Application (CEA).

Review on energetic copolymer binders for propulsion applications: Synthesis and properties

Journal of Polymer Science

Akbi

et al. 2023

This article aims to outline the current progress in the field of energetic copolymer binders for composite solid propellants (CSPs). Propellants, which are a type of energetic material, are used to generate thrust in rockets and missiles, and they are generally less sensitive than explosives. The common formulations of CSPs contain several different chemical compounds that are typically bound together by a polymeric matrix to form a continuous solid. The use of inert polymers, however, does not enhance the overall specific impulse of the propellant. Energetic copolymers have emerged as a compelling category of binders for CSPs in recent years, offering potential advantages over traditional binders such as improved performance, enhanced safety, and increased manufacturing efficiency. The paper reviews the various types of energetic copolymer binders that have been developed, their potential advantages and drawbacks, and the current challenges and opportunities in the field. It suggests directions for future research and development and aims to provide a useful resource for researchers and practitioners interested in the use of energetic copolymer binders toward CSPs.