FirePhysChem最新文献

{"title":"Effect of the accelerated aging process on the thermal decomposition of LiAlH4-based composite solid propellants","authors":"Fateh Chalghoum ,&nbsp;Mohammed Jouini ,&nbsp;Amir Abdelaziz ,&nbsp;Ahmed Fouzi Tarchoun ,&nbsp;Hani Boukeciat ,&nbsp;Slimane Bekhouche ,&nbsp;Mokhtar Benziane ,&nbsp;Djalal Trache","doi":"10.1016/j.fpc.2024.07.002","DOIUrl":"10.1016/j.fpc.2024.07.002","url":null,"abstract":"<div><div>In the present work, a study was carried out on the effect of the accelerated aging process on the thermal decomposition of two composite solid propellants based on ammonium perchlorate (AP) and hydroxy‑terminated polybutadiene (HTPB). The first one (CP1) was enriched with aluminum (Al) powders, while the second (CP2) contained a mixture of aluminum and lithium alanate (LiAlH₄) as a high-energy fuel additive. The thermal properties of the investigated propellant samples were determined using differential scanning calorimetry (DSC) and thermogravimetry (TG) techniques. The obtained results clearly demonstrated the effect of the aging process on the thermal degradation of the aged samples compared to the unaged ones, by shifting the temperature peaks of their main decomposition step to lower temperatures with a decrease in their DSC heat release. In addition, the residual unburnt propellant was increased, particularly for the complex metal hydride-based propellant. Kinetic modeling of the main thermal degradation phase, applying two advanced isoconversional methods, revealed a significant decrease in activation energy for the aged samples. Furthermore, the three-dimensional diffusion model involved during the investigated decomposition phase of the unaged samples was changed to a random nucleation model after 60 days of aging time.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 91-100"},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing accuracy in equivalent in-service-time assessment for homogeneous solid propellants: A novel temperature-independent predictive model utilizing PCA of FTIR data","authors":"Salim Chelouche ,&nbsp;Djalal Trache ,&nbsp;Amir Abdelaziz ,&nbsp;Ahmed Fouzi Tarchoun ,&nbsp;Slimane Bekhouche ,&nbsp;WeiQiang Pang","doi":"10.1016/j.fpc.2024.06.001","DOIUrl":"10.1016/j.fpc.2024.06.001","url":null,"abstract":"<div><div>The present study was devoted to setting a universal <em>T</em>-independent predictive model of equivalent in-service-time (EIST) for homogenous solid propellant (HSP) to surpass the limits of the van't Hoff law particularly when high aging temperatures and/or extended aging durations are employed in artificial aging plans. To achieve this objective, four double base rocket propellants (DBRP) underwent artificial aging for 4 months at temperatures of 323.65 K, 338.65 K, 353.65 K, and 368.65 K, with sampling conducted every 20 days. Fourier Transform Infrared spectrometry (FTIR) showed that the homolytic scission of the O<img>NO₂ bonds and the hydrocarbon chains of the nitrate esters are the main processes occurring during the chemical decomposition. With the heating temperature increase, the chemical decomposition becomes more predominant. Furthermore, the scatter plot from Principal Component Analysis (PCA) of FTIR spectra obtained from each aging temperature showed, respectively, that over than 88.9 %, 94.3 %, 97.4 %, and 98.6% of the variances were described by the first principal component. This latter value was found 97.6 % when PCA was applied to all FTIR spectra. Using the PCA/FTIR approach recently developed, EIST was assessed for all the investigated samples. Subsequently, an individual predictive model of EIST was set for each heating temperature, which were used to establish the <em>T</em>-independent predictive model. The final model computed the EIST with a relative deviation of 5.3 % compared to those from the PCA/FTIR experimental way. Moreover, two similar DBRPs aged at different temperatures and durations have been used to validate the predictive model, and the associated mean absolute percentage error (MAPE) was found 4.6 %. The conducted comprehensive statistical analysis highlighted the excellent goodness-of-fit of the model. Furthermore, all the error metrics were found to decrease with the increase of the natural aging of the propellant and the heating temperature.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 74-90"},"PeriodicalIF":0.0,"publicationDate":"2024-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141393813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards to some published misconceptions about TNT and ɛ-CL20","authors":"Svatopluk Zeman,&nbsp;Veerabhadragouda B. Patil","doi":"10.1016/j.fpc.2024.05.007","DOIUrl":"10.1016/j.fpc.2024.05.007","url":null,"abstract":"<div><div>The literature widely reported information about apparent high impact sensitivities of both the pure 2,4,6-trinitrotoluene (TNT; i.e. of 14–16 J) and ɛ-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ɛ-CL20; i.e. of 2–4.4 J), which mostly correspond to the BAM method of determination. This brief overview discusses the reasons of these error data. The physical organic chemistry approach to this problem has confirmed the Beijing Inst. of Technology value of 13.2 J for ɛ-CL20 and the LANL value of 39.2 J for TNT. The morphological instability of ɛ-CL20, when in contact with polar binders or plasticizers, might not have much influence on its application in propellants. The stabilization of ɛ- to β-CL20 upon its entry into a cocrystal with a coformer having the character of a polynitro compound (especially with nitramines) could be of practical importance. The high impact sensitivity of TNT and ɛ-CL20 is important for handling and processing safety when related to the specific practical samples. However, they cannot be used for molecular-structural analyses and predictions or as a comparative standard, which is currently widespread in the literature.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 68-73"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141397063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the combustion mechanism of single micron-sized aluminum particles with a numerical model","authors":"Xinzhe Chen ,&nbsp;Jiaxin Liu ,&nbsp;Yabei Xu ,&nbsp;Di Zhang ,&nbsp;Yong Tang ,&nbsp;Baolu Shi ,&nbsp;Yunchao Feng ,&nbsp;Yingchun Wu ,&nbsp;Qingzhao Chu ,&nbsp;Dongping Chen","doi":"10.1016/j.fpc.2024.05.006","DOIUrl":"10.1016/j.fpc.2024.05.006","url":null,"abstract":"<div><div>In this work, we explore the combustion mechanism of single micron-sized aluminum particles using a numerical model. The Burcat database and Catoire mechanism is considered as the thermodynamic data and the kinetic mechanism for our numerical model of aluminum combustion. Two independent experiments, including particle temperature profiles, ignition delay and burning time, are selected to evaluate the performance of the numerical model. The model shows great agreement for all considered properties. A parametric study is further conducted to identify the effect of involved physical parameters on the combustion process. The diffusion coefficient (<em>D</em>) of oxidizers and the activation energy of surface kinetics (<em>E</em>_surf) and evaporation coefficient (<em>α</em>) of aluminum impact the particle temperature the most. Burning time is most sensitive to the activation energy of surface kinetics (<em>E</em>_surf). The optical measurement in a solid propellant combustion indicates that the contact angle of the oxide cap on Al particle is between 10° and 20°. It is found that the selection of contact angle of the oxide cap significantly impacts the prediction of combustion time and residual of active aluminum. The current work highlights the importance of physical properties on the prediction of Al combustion, suggesting that more detailed evaluation from experiments and theory is encouraged.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 57-67"},"PeriodicalIF":0.0,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial From the Guest Editors","authors":"","doi":"10.1016/S2667-1344(24)00029-4","DOIUrl":"https://doi.org/10.1016/S2667-1344(24)00029-4","url":null,"abstract":"","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"4 2","pages":"Pages i-iii"},"PeriodicalIF":0.0,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667134424000294/pdfft?md5=1dbd659b95da88fcff978683d1add0c9&pid=1-s2.0-S2667134424000294-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141096126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical compatibility of energetic metal complexes with polymers by thermal analytical techniques","authors":"Priyanka Singla ,&nbsp;Rajesh Kumar ,&nbsp;Pramod Kumar Soni ,&nbsp;Subash Chandra Sahoo ,&nbsp;Arjun Singh","doi":"10.1016/j.fpc.2024.05.005","DOIUrl":"10.1016/j.fpc.2024.05.005","url":null,"abstract":"<div><div>Energetic metal complexes have been established to be effective combustion catalyst for energetic composites and propellants with improved performance. Chemical compatibility is an important aspect in the development of novel energetic composites which are related to safe processing, handling, and storage. In the present paper, the compatibility of energetic metal complexes [Zn(atrz)(DNBA)₂(H₂O)₂]_<em>n</em> (complex <strong>1</strong>) and [Cd(atrz)(DNBA)₂(H₂O)₂]_n (complex <strong>2</strong>) with Viton A and epoxy resin as polymer binder are studied by thermal analytical techniques. The compatibility was studied through vacuum stability test (VST), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) according to standardization agreement (STANAG) 4147 method. Furthermore, physicochemical methods including powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR) are used to support the thermal analytical methods. The VST results indicate that the volume of gases evolved for complex <strong>1</strong>/Viton A, complex <strong>1</strong>/epoxy resin, complex <strong>2</strong>/Viton A, and complex <strong>2</strong>/epoxy resin is found to be 0.545 mL/g, 0.86 mL/g, 0.403 mL/g, and 0.884 mL/g, respectively, indicating high compatibility with one another. According to the STANAG 4147 criteria, the DSC/DTG data demonstrate that the difference in <em>T</em>_max is less than 2 °C for all the admixtures, suggesting that the polymer binders under investigation are compatible with complexes. TG results demonstrate that the mass loss difference is less than 4 % for all admixtures, indicating good compatibility. The essential additional information offered by the supplementary non-thermal FTIR and PXRD techniques confirm that no reaction occurs between metal complex and polymer. SEM micrographs exhibit that metal complex crystals are embedded in the polymer matrix.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 45-56"},"PeriodicalIF":0.0,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141131754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the performance of ceramic/fabric composite panels against simultaneous steel projectile impacts: An experimental and numerical study","authors":"M.D. Umbharatwala,&nbsp;S.S. Raut,&nbsp;Manmohan Dass Goel","doi":"10.1016/j.fpc.2024.05.004","DOIUrl":"10.1016/j.fpc.2024.05.004","url":null,"abstract":"<div><div>In order to evaluate the ballistic performance of ceramic/fabric composite panels developed using 99.5 % alumina, Kevlar® and carbon fiber fabrics; a series of experiments were performed on the physical samples. The composite-projectile interaction was investigated in detail by means of finite element analysis using LS-DYNA®. The validated numerical model of the ceramic/fabric composite system was tactically modified to investigate the composite/projectile interaction for simultaneous projectile impacts at different impact velocities. The numerical model predicted the failure mechanism of the composite panel and the exit velocity of the projectile piercing through the composite accurately. This study reveals the important aspects of ballistic impact on composites under simultaneous multiple projectile impact condition which in turn, is a much more complex and critical case as compared to sequential multiple projectile impacts.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 36-44"},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141040809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of propellant grade HHTPB by hydrogenation of HTPB using Pd-activated charcoal as catalyst","authors":"Ch. Devi Vara Prasad ,&nbsp;P. Kanakaraju ,&nbsp;R Vinu ,&nbsp;Abhijit P Deshpande","doi":"10.1016/j.fpc.2024.05.001","DOIUrl":"10.1016/j.fpc.2024.05.001","url":null,"abstract":"<div><div>To derive more performance from the conventional composite propellant based on hydroxyl-terminated polybutadiene (HTPB) and ammonium perchlorate (AP), it is envisaged to hydrogenate HTPB, which increases the H/C (hydrogen to carbon ratio) of the base polymer. This paper attempts to describe the partial hydrogenation of HTPB using a catalytic method that uses palladium supported by activated charcoal as a catalyst and HTPB polymer as a precursor. HTPB has a hydroxyl value of 41.0 mg KOH/g with a number-average molecular weight (Mn) of 6150, polydispersity (PD) of 2.25 was used as a precursor. Iso-propyl alcohol (IPA) and toluene were used as a solvent media to disperse the HTPB polymer during hydrogenation. The estimate revealed an increase in specific impulse (ISP) up to 1.2 s with ∼37 % hydrogenated HTPB (HHTPB) as binder in composite solid propellants. Partial hydrogenation is only attempted to retain other process capabilities essential for realizing a defect-free solid propellant grain with good structural integrity. In contrast, others attempted to reach near saturation. A reactor capacity of 100 ml, operating at 60 bar pressure, was used to synthesize HHTPB, and the extent of hydrogenation was controlled based on the numerous experiments varying the reactor parameters like operating temperature, operating pressure, and solvent-to-polymer ratio for a given catalyst concentration. Detailed characterization of the end product by FTIR, ¹H NMR and ¹³C NMR to reveal the degree of hydrogenation along with generic polymer characteristics. The measured hydroxyl value of HHTPB is comparable with HTPB; however, a marginal increase in molecular weight and polydispersity was noticed at 37 % conversion, wherein other researchers found a loss in -OH value. Thermogravimetry analysis revealed that no significant change in the gasification rate. A slight increase in the H/C ratio and calorific value was observed for HHTPB compared to HTPB. Despite the increase in viscosity of HHTPB, the increase in the vinyl-type functional distribution of HHTPB aids for better process-ability during propellant processing. However, the propellant formulation should be optimized with the help of plasticizers, solid loading, etc., to achieve the required properties.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 7-14"},"PeriodicalIF":0.0,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141026711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Core-shell structured α-AlH3/Fe2O3 thermite with improved heat-release and combustion performance","authors":"Jiashuai Wang ,&nbsp;Bo Wu ,&nbsp;Lingfeng Yang ,&nbsp;Yuan Bian ,&nbsp;Renjie Li ,&nbsp;Ke Zeng ,&nbsp;Juan Zhu ,&nbsp;Liangyou Zhao ,&nbsp;Jinpeng Shen ,&nbsp;Chonghua Pei","doi":"10.1016/j.fpc.2024.05.003","DOIUrl":"10.1016/j.fpc.2024.05.003","url":null,"abstract":"<div><div>Thermites are widely used in propellants, explosives and ignition materials because of their high heat release rate and good combustion efficiency. Structural control over thermites to achieve improved performance leads to a promising research area. Among these, core-shell structured composites have attracted wide attention due to their excellent properties and close contact among components. Herein, core-shell structured <em>α</em>-AlH₃/Fe₂O₃ thermites were prepared, which exhibit high heat-release and excellent combustion performance. At an equivalence ratio of 2.0, the core-shell structured <em>α</em>-AlH₃/Fe₂O₃ has the most heat release (1213.8 J/g) and the lowest reaction activation energy (147.5 kJ/mol). The ignited combustion performance of <em>α</em>-AlH₃/Fe₂O₃ was notably strengthened by the shorter ignition delay period (11 ms). Interestingly, the core-shell structured <em>α</em>-AlH₃/Fe₂O₃ was less sensitive to electrostatic discharge, which suggests that the core-shell structured <em>α</em>-AlH₃/Fe₂O₃ reaches the goal of high energy release and electrostatic safety. The core-shell thermite system with <em>α</em>-AlH₃ as metal fuel could provide an efficient alternative to hunt for thermites with high reactivity.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 28-35"},"PeriodicalIF":0.0,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141055874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitramino-polymer with ether bridges and 1,2,3-triazole subunits incorporated into the polymer chain","authors":"Pavel S. Gribov ,&nbsp;Natalia N. Il'icheva ,&nbsp;Natalia N. Kondakova ,&nbsp;Evgenia R. Stepanova ,&nbsp;Anatoly P. Denisyuk ,&nbsp;Vladimir A. Sizov ,&nbsp;Varvara D. Dotsenko ,&nbsp;Valery P. Sinditskii ,&nbsp;Aleksei B. Sheremetev","doi":"10.1016/j.fpc.2024.05.002","DOIUrl":"10.1016/j.fpc.2024.05.002","url":null,"abstract":"<div><div>The creation of novel energetic polymers for future advanced solid composite propellants and gunpowder is an urgent area of modern research. A simple and effective waste-free cycloaddition reaction between dialkyne and diazide comonomers, both bearing nitramine groups, for the synthesis of an energetic polymer containing explosophoric units in the polymer chain has been described. Neither solvent nor catalyst is required for the production of this polymer, the comonomers used are readily available, and the product does not need any purification, and, importantly, this protocol scales well. The resulting polymer, <strong>C1Z1</strong>, (C₁₄H₂₂N₁₂O₈)_<em>n</em>, was comprehensively characterized by spectral and physico-chemical methods. Compatibility with energetic plasticizers (<strong>NG, DNDEG, DANPE</strong>), thermochemical characteristics and combustion features indicate the prospects of target polymer <strong>C1Z1</strong> (density, <em>ρ</em> = 1.484 g/cm³; onset temperatures is 230 °C; positive enthalpy of the formation, Δ<em>H</em>_f⁰ = +636 kJ/kg; burning rate at 10 MPa is 9.5 mm/s) as a binder base for energetic materials. Comparison of <strong>C1Z1</strong> with nitrocellulose (<strong>NC</strong>) and their compositions with plasticizers revealed the advantages of <strong>C1Z1</strong>.</div></div>","PeriodicalId":100531,"journal":{"name":"FirePhysChem","volume":"5 1","pages":"Pages 15-27"},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141043357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}