Shelf Life Prediction of Propellants Using a Reaction Severity Index

Dubois, Charles; Perreault, François

doi:10.1002/1521-4087(200211)27:5<253::aid-prep253>3.0.co;2-8

Cited by 16 publications

(10 citation statements)

References 8 publications

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“…Nevertheless, due to the unsaturated character of the repeated unit, polybutadiene is well-known to be sensitive to oxidation, even in the presence of stabilizers 2 , thus resulting in hardening and embrittlement of HTPB-based polyurethanes, which are attributed to the cross-linkage through the double bonds of polybutadiene 3 . Therefore, depending on the environmental conditions, changes on mechanical properties of propellant binders may compromise the structural integrity of solid rockets, leading to service life constraints 4 . Since the service life of rockets are largely dependent on the behavior of mechanical properties during aging, a formulation parameter such as NCO/OH ratio, which undoubtfully affects the mechanical properties 5,6 , may also affect the aging behavior of solid propellant binders and, by doing so, the reliability of rocket systems.…”

Section: Introductionmentioning

confidence: 99%

Thermal aging of HTPB/IPDI-based polyurethane as a function of NCO/OH ratio

et al. 2011

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Thermal aging of hydroxy-terminated polybutadiene/isophorone diisocyanate (HTPB/IPDI)-based polyurethane was studied as a function of NCO/OH ratio (1.0 and 0.85). Samples were aged in air ovens at 50, 60, 65, and 70 °C for periods of time from 1 to 34 weeks. Changes in chemical (swelling testing and FT-IR spectroscopy) and mechanical (tension testing and hardness) properties were evaluated throughout the aging assays. Correlation between equilibrium swelling ratio and elastic modulus, coupled with changes in FT-IR spectra, indicated oxidative cross-linking as the dominant mechanism for both molar ratios investigated. However, determination of Arrhenius activation energy resulted in values of (82 ± 10) kJ.mol -1 and (156 ± 30) kJ.mol -1 for 1.0 and 0.85 NCO/OH ratios, respectively, thus revealing faster oxidative degradation kinetics for higher urethane linkage networks.

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Section: Introductionmentioning

confidence: 99%

Thermal aging of HTPB/IPDI-based polyurethane as a function of NCO/OH ratio

et al. 2011

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“…So, tensile strength is selected as degradation criteria and not the end requirement. In fact many degradation mechanisms are possible for composite propellants and it cannot be attributed to any single reason 9 .…”

Section: Resultsmentioning

confidence: 99%

“…However, due to chemical cross-linking in composite propellants, it is difficult to apply the same criteria to the composite propellants. Failure of Arrehenius type degradation equations to predict ageing behaviour of composite propellants is deliberated in open literature 9 . Modeling for ageing of HTPB based composite propellants using different activation energy is carried out and effect on shelf-life is established 10 .…”

Section: Introductionmentioning

confidence: 99%

Studies on Stress-Strain Curves of Aged Composite Solid Rocket Propellants

Shekhar¹

2012

DSJ

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Mechanical property evaluation of composite solid rocket propellants is used as a quick quality control tool for propellant development and production. However, stress-strain curves from uni-axial tensile testing can be utilised to assess the shelf-life of propellants also. Composite propellants (CP) of two varieties cartridge-loaded (CLCP) and case-bonded (CBCP) are utilized in rocket and missile applications. Both classes of propellants were evaluated for mechanical properties namely tensile strength, modulus and percentage elongation using specimens conforming to ASTM D638 type IV at different ageing time. Both classes of propellants show almost identical variation in various mechanical properties with time. Tensile strength increases with time for both classes of propellants and percentage elongation reduces. Initial modulus is also found to decrease with time. Tensile strength is taken as degradation criteria and it is observed that CLCP has slower degradation rate than CBCP. This is because of two facts-(i) higher initial tensile strength of CLCP (1.39 MPa) compared to CBCP (0.665 MPa) and (ii) lower degradation rate of CLCP (0.0014 MPa/day) with respect to CBCP (0.0025 MPa/day). For the studied composite propellants, a degradation criterion in the form of percentage change in tensile strength is evaluated and shelf life for different degradation criteria is tabulated for quick reference.

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“…In recent years, some scholars have carried out research on the physical and chemical properties of propellant from the perspective of thermal analysis kinetics, and used the reaction kinetic equation to describe the degradation mechanism of its performance parameters and obtained some research results. Dubois and Perreault [13] carried out related research earlier, and proposed a new approach for accelerated aging studies of the degradation of the polymeric binder in such propellant formulations. Using a reaction severity index, simple first order kinetic models had been demonstrated to adequately model the degradation behaviour of various propellants submitted to isothermal aging.…”

Section: Introductionmentioning

confidence: 99%

Storage Lifetime Prediction of Composite Solid Propellant based on Šesták‐Berggren Model

Pan

2021

Propellants Explo Pyrotec

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The physical and chemical properties of composite solid propellant during storage period are greatly affected by environmental factors, and the aging mechanism is complicated. In view of the insufficient utilization of test data in the current research and the low accuracy of storage lifetime evaluation model, this paper takes composite solid propellant as the object and makes use of the destructive accelerated storage test data at different temperature levels to carry out storage lifetime prediction research from the perspective of thermal analysis kinetics. Taking the key mechanical performance parameter‐tensile strength as an example, a performance degradation model based on Šesták‐Berggren model (SB(m,n)) is established, and the optimal mechanism index (m,n) is determined according to the Akaike Information Criterion (AIC). Furthermore, the evaluation methods of storage reliability, storage reliable lifetimes and their lower confidence limits are given. Finally, take a certain type of composite solid propellant as an example to verify the model and method of the paper. The results show that the storage lifetime prediction method based on the SB(m,n) model is more accurate and the prediction results are more reliable. A good idea is provided to assess the storage lifetime of composite solid propellant, and it also provides reference for other propellant and explosive storage lifetime prediction.

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Shelf Life Prediction of Propellants Using a Reaction Severity Index

Cited by 16 publications

References 8 publications

Thermal aging of HTPB/IPDI-based polyurethane as a function of NCO/OH ratio

Thermal aging of HTPB/IPDI-based polyurethane as a function of NCO/OH ratio

Studies on Stress-Strain Curves of Aged Composite Solid Rocket Propellants

Storage Lifetime Prediction of Composite Solid Propellant based on Šesták‐Berggren Model

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