Xiao‐lan Song, Yi Wang, Kang‐hui Jia, Zhi‐hong Yu, Dan Song, Chong‐wei An, Feng‐sheng Li
A new carrier explosive TNBA was batch synthesized by a chemical method. The prepared samples were characterized using SEM, EDS, XRD, IR, XPS, nuclear magnetic resonance, and elemental analysis techniques. The enthalpy of formation of TNBA was measured using a specialized calorimeter that is specially used in testing of explosives and powders. The thermal decomposition performance of TNBA was tested by DSC technology. Meanwhile, the combustion performance of TNBA was also tested. The results of characterizations showed that the prepared sample was indeed TNBA. The enthalpy of formation of TNBA was determined as ΔHf,TNBA=+48.5 kJ/mol. At a heating rate of 20 °C/min, the thermal decomposition peak of TNBA is at TP=285.3 °C, and the activation energy is EK=91 kJ/mol, which is higher than the Tp and EK values of TNT. This indicates that TNBA is a relatively easy to decompose explosive, but the decomposition rate is not fast. The critical temperature for thermal explosion of TNBA reached Tb=247 °C, which is higher than the Tb value of TNT, slightly lower than the Tb value of DNAN, and significantly higher than the Tb value of DNTF, TNAZ, and MTNP. The combustion performance test results showed that the TNBA sample has the highest combustion pressure and the highest pressurization rate; and the TNBA sample has the highest combustion temperature; however, due to the high oxygen balance, the combustion heat of TNBA samples in excess pure oxygen is not the highest.
{"title":"Batch synthesis of 2,4,6‐trinitro‐3‐bromoanisole and its thermolysis and combustion performance","authors":"Xiao‐lan Song, Yi Wang, Kang‐hui Jia, Zhi‐hong Yu, Dan Song, Chong‐wei An, Feng‐sheng Li","doi":"10.1002/prep.202400009","DOIUrl":"https://doi.org/10.1002/prep.202400009","url":null,"abstract":"A new carrier explosive TNBA was batch synthesized by a chemical method. The prepared samples were characterized using SEM, EDS, XRD, IR, XPS, nuclear magnetic resonance, and elemental analysis techniques. The enthalpy of formation of TNBA was measured using a specialized calorimeter that is specially used in testing of explosives and powders. The thermal decomposition performance of TNBA was tested by DSC technology. Meanwhile, the combustion performance of TNBA was also tested. The results of characterizations showed that the prepared sample was indeed TNBA. The enthalpy of formation of TNBA was determined as Δ<jats:italic>H</jats:italic><jats:sub><jats:italic>f,TNBA</jats:italic></jats:sub>=+48.5 kJ/mol. At a heating rate of 20 °C/min, the thermal decomposition peak of TNBA is at T<jats:sub>P</jats:sub>=285.3 °C, and the activation energy is E<jats:sub>K</jats:sub>=91 kJ/mol, which is higher than the T<jats:sub>p</jats:sub> and E<jats:sub>K</jats:sub> values of TNT. This indicates that TNBA is a relatively easy to decompose explosive, but the decomposition rate is not fast. The critical temperature for thermal explosion of TNBA reached T<jats:sub>b</jats:sub>=247 °C, which is higher than the T<jats:sub>b</jats:sub> value of TNT, slightly lower than the T<jats:sub>b</jats:sub> value of DNAN, and significantly higher than the T<jats:sub>b</jats:sub> value of DNTF, TNAZ, and MTNP. The combustion performance test results showed that the TNBA sample has the highest combustion pressure and the highest pressurization rate; and the TNBA sample has the highest combustion temperature; however, due to the high oxygen balance, the combustion heat of TNBA samples in excess pure oxygen is not the highest.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"41 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141195517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To investigate the effect of aluminum (Al) nanoparticles on the energy release mechanism of high explosives, a comprehensive analysis was conducted on the mechanical response and chemical reaction mechanism of pure 1,3,5‐Trinitro‐1,3,5‐triazinane (RDX) and nano‐aluminized RDX across varying particle velocities using molecular dynamics simulation. The simulation results show that the velocity of the shock wave which is formed in the explosive increases as the velocity of the particle increases. Notably, detonation was absent when the particle velocity was below 3 km/s, but prominently observed beyond this threshold, accompanied by a diminishing delay in reaction time for aluminum particles as particle velocity increased. After detonation, a localized pressure reduction behind aluminum particles was observed, elucidating the diminished detonation efficacy of aluminized explosives. Furthermore, the introduction of aluminum particles led to a deceleration in the RDX reaction rate, with the emergence of aluminum atomic clusters highlighting previously overlooked gas‐phase reactions that necessitate inclusion in detonation modeling for aluminized explosives.
{"title":"Activation and reaction mechanism of nano‐aluminized explosives under shock wave","authors":"Zhandong Wang, Chuan Xiao, Fang Chen, Shuang Wang, Liangliang Zhang, Qingzhao Chu","doi":"10.1002/prep.202300318","DOIUrl":"https://doi.org/10.1002/prep.202300318","url":null,"abstract":"To investigate the effect of aluminum (Al) nanoparticles on the energy release mechanism of high explosives, a comprehensive analysis was conducted on the mechanical response and chemical reaction mechanism of pure 1,3,5‐Trinitro‐1,3,5‐triazinane (RDX) and nano‐aluminized RDX across varying particle velocities using molecular dynamics simulation. The simulation results show that the velocity of the shock wave which is formed in the explosive increases as the velocity of the particle increases. Notably, detonation was absent when the particle velocity was below 3 km/s, but prominently observed beyond this threshold, accompanied by a diminishing delay in reaction time for aluminum particles as particle velocity increased. After detonation, a localized pressure reduction behind aluminum particles was observed, elucidating the diminished detonation efficacy of aluminized explosives. Furthermore, the introduction of aluminum particles led to a deceleration in the RDX reaction rate, with the emergence of aluminum atomic clusters highlighting previously overlooked gas‐phase reactions that necessitate inclusion in detonation modeling for aluminized explosives.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"51 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141195516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to investigate the primary factors influencing hot‐spot formation in emulsion explosives sensitized by hydrogen‐storage glass microballoons (GMBs), we conducted impact calculations on hydrogen‐storage GMBs. The calculations focused on tracking two main mechanisms: the brittle collapse of GMBs and the adiabatic compression of internal gas. Various parameters were considered, including loading pressures, initial porosities, gas types, and initial gas pressures. Our findings indicate that the contribution of brittle collapse to hot‐spot formation is negligible, while adiabatic compression emerges as the predominant intrinsic mechanism for hot‐spot ignition in GMB‐sensitized emulsion explosives. Moreover, we observed that the ignition time remains similar for low‐pressure nitrogen and high‐pressure hydrogen. The addition of hydrogen does not result in an increased number of hot‐spots; however, it elevates the energy of each individual hot‐spot, thereby enhancing power delivery. Optimal selection of GMB size is crucial for hot‐spot formation and hydrogen storage. GMBs that are excessively large are prone to shell breakage, while overly small GMBs have limited hydrogen storage capacity. GMBs within the size range of 20 μm to 100 μm are deemed more suitable for emulsion explosives.
{"title":"Mechanism of hot‐spot formation of emulsion explosives sensitized by hydrogen‐storage glass microballoons","authors":"Yixin Wang, Honghao Ma, Zhaowu Shen, Jiping Chen","doi":"10.1002/prep.202300335","DOIUrl":"https://doi.org/10.1002/prep.202300335","url":null,"abstract":"In order to investigate the primary factors influencing hot‐spot formation in emulsion explosives sensitized by hydrogen‐storage glass microballoons (GMBs), we conducted impact calculations on hydrogen‐storage GMBs. The calculations focused on tracking two main mechanisms: the brittle collapse of GMBs and the adiabatic compression of internal gas. Various parameters were considered, including loading pressures, initial porosities, gas types, and initial gas pressures. Our findings indicate that the contribution of brittle collapse to hot‐spot formation is negligible, while adiabatic compression emerges as the predominant intrinsic mechanism for hot‐spot ignition in GMB‐sensitized emulsion explosives. Moreover, we observed that the ignition time remains similar for low‐pressure nitrogen and high‐pressure hydrogen. The addition of hydrogen does not result in an increased number of hot‐spots; however, it elevates the energy of each individual hot‐spot, thereby enhancing power delivery. Optimal selection of GMB size is crucial for hot‐spot formation and hydrogen storage. GMBs that are excessively large are prone to shell breakage, while overly small GMBs have limited hydrogen storage capacity. GMBs within the size range of 20 μm to 100 μm are deemed more suitable for emulsion explosives.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"120 17-18 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141195518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thomas M. Klapötke, Burkhard Krumm, Christian Riedelsheimer
Many currently used energetic materials need to be replaced with new compounds due to toxicity or other drawbacks. Among these is the oxidizer ammonium perchlorate, often used in solid state propellants, which itself, as well as its combustion products, poses health and environmental issues. Herein, three new polynitro energetic compounds are presented containing trinitroethyl moieties. Starting from easily available starting materials, such as malonic acid ethylester, diglycolic and diaminodiacetic acid, simple and straightforward syntheses were performed to obtain first the corresponding hydrazides and subsequently the trinitroethyl hydrazides in good yields and high purity. These compounds have a positive oxygen balance (assuming to the formation of CO), a high oxygen and nitrogen content and moderate densities. Full characterization was performed by NMR spectroscopy, vibrational analysis and elemental analysis. By using the Gaussian program package, the heats of formation were calculated and the energetic parameters were estimated utilizing the EXPLO5 computer code.
{"title":"Trinitroethyl hydrazides of dicarbonic acids – Energetic compounds with high oxygen and nitrogen content","authors":"Thomas M. Klapötke, Burkhard Krumm, Christian Riedelsheimer","doi":"10.1002/prep.202300266","DOIUrl":"https://doi.org/10.1002/prep.202300266","url":null,"abstract":"Many currently used energetic materials need to be replaced with new compounds due to toxicity or other drawbacks. Among these is the oxidizer ammonium perchlorate, often used in solid state propellants, which itself, as well as its combustion products, poses health and environmental issues. Herein, three new polynitro energetic compounds are presented containing trinitroethyl moieties. Starting from easily available starting materials, such as malonic acid ethylester, diglycolic and diaminodiacetic acid, simple and straightforward syntheses were performed to obtain first the corresponding hydrazides and subsequently the trinitroethyl hydrazides in good yields and high purity. These compounds have a positive oxygen balance (assuming to the formation of CO), a high oxygen and nitrogen content and moderate densities. Full characterization was performed by NMR spectroscopy, vibrational analysis and elemental analysis. By using the Gaussian program package, the heats of formation were calculated and the energetic parameters were estimated utilizing the EXPLO5 computer code.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140941147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of slit plate design on PBXs quality was systematically studied from the point of view voids and powder‐binder separation phenomenon. PBXN‐109 type explosive samples were prepared in accordance with MIL−E‐82886 and cast through slit plates of different geometry and perforation size. The other casting parameters such as casting time, temperature, pressure, valve opening and PBX amount kept constant to prevent uncertainties arising from these parameters. Density measurements, X‐ray inspection and tensile tests were carried out to evaluate the air removal and powder‐binder separation characteristic of slit plates. Density measurements did not provide a clear interpretation of the powder‐binder separation and deaeration abilities of slit plates. X‐ray inspections and tensile tests showed that the dimensions and design of slit plate perforations have impact on voids and powder‐binder separation in PBXs. The slit plate #E showed relatively poor performance in terms of stress property, attributed to the largest cross‐sectional area per perimeter length ratio of perforations, leading to decrease in air removal ability.
{"title":"Effects of slit plate design on mechanical properties of castable plastic bonded explosives","authors":"Alper Sevinc, Baris Edis","doi":"10.1002/prep.202300340","DOIUrl":"https://doi.org/10.1002/prep.202300340","url":null,"abstract":"The effect of slit plate design on PBXs quality was systematically studied from the point of view voids and powder‐binder separation phenomenon. PBXN‐109 type explosive samples were prepared in accordance with MIL−E‐82886 and cast through slit plates of different geometry and perforation size. The other casting parameters such as casting time, temperature, pressure, valve opening and PBX amount kept constant to prevent uncertainties arising from these parameters. Density measurements, X‐ray inspection and tensile tests were carried out to evaluate the air removal and powder‐binder separation characteristic of slit plates. Density measurements did not provide a clear interpretation of the powder‐binder separation and deaeration abilities of slit plates. X‐ray inspections and tensile tests showed that the dimensions and design of slit plate perforations have impact on voids and powder‐binder separation in PBXs. The slit plate #E showed relatively poor performance in terms of stress property, attributed to the largest cross‐sectional area per perimeter length ratio of perforations, leading to decrease in air removal ability.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"22 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140941148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Justin A. Lajoie, Brock Jones, Adam R. Lawrence, Stuart J. Barkley, Travis R. Sippel
This study demonstrates, for the first time ever, the ability to grow, in an on‐command fashion, porosity within a granular composite energetic material to effect a change in energy output rate. Specifically, the study investigates the change in burning rates of ammonium perchlorate composite propellants as a result of porosity created in situ via microwave field‐driven volatilization of the low boiling point binder additive, ethylene glycol. Theoretical mass densities were measured before and after microwave irradiation finding that the maximum observed %TMD change for tested propellants is 6 %. Propellants were burned at 1.72 MPa to 6.89 MPa pressures, finding that for all propellants, microwave irradiation produced a change in ballistic characteristics. Most propellant formulations demonstrate acceptable burning rate parameters for use within rocket motors; some exhibited a large change in their pressure exponent as well as slope breaks attributed to the onset of convective burning, while microwave irradiation produced no change in burning rate or density in reference propellants without the additive. Microwave heating simulation results are presented to gain insight into the thermal environment of the propellant during microwave irradiation. These results provide valuable insight into propellant formulations that can have their burning rates (and thus the thrust profile for motor grains) altered after casting via microwave irradiation.
{"title":"On‐demand microwave growth of porosity within a granular composite energetic material: Void formation via a dielectric loss phase change binder additive for propellant burning rate control","authors":"Justin A. Lajoie, Brock Jones, Adam R. Lawrence, Stuart J. Barkley, Travis R. Sippel","doi":"10.1002/prep.202300229","DOIUrl":"https://doi.org/10.1002/prep.202300229","url":null,"abstract":"This study demonstrates, for the first time ever, the ability to grow, in an on‐command fashion, porosity within a granular composite energetic material to effect a change in energy output rate. Specifically, the study investigates the change in burning rates of ammonium perchlorate composite propellants as a result of porosity created in situ via microwave field‐driven volatilization of the low boiling point binder additive, ethylene glycol. Theoretical mass densities were measured before and after microwave irradiation finding that the maximum observed %TMD change for tested propellants is 6 %. Propellants were burned at 1.72 MPa to 6.89 MPa pressures, finding that for all propellants, microwave irradiation produced a change in ballistic characteristics. Most propellant formulations demonstrate acceptable burning rate parameters for use within rocket motors; some exhibited a large change in their pressure exponent as well as slope breaks attributed to the onset of convective burning, while microwave irradiation produced no change in burning rate or density in reference propellants without the additive. Microwave heating simulation results are presented to gain insight into the thermal environment of the propellant during microwave irradiation. These results provide valuable insight into propellant formulations that can have their burning rates (and thus the thrust profile for motor grains) altered after casting via microwave irradiation.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"206 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140630122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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