Nano-thermites or metastable intermolecular composites (MICs) have been implemented into modern research on energetic materials as they offer much higher energy densities, higher rates of energy release, stability, and safety (lower sensitivity). This paper reviews several synthetic methods for MICs that have been well thought-out for energetic applications, advantages and disadvantages, as well as the characteristics of each manufacturing technique. The techniques presented include powder mixing, sol-gel, synthesis of MICs based on nano-porous silicon (Psi), sputtering, multilayer nano-foils and electrolytically plated carbon nano-materials for nano-thermite applications. These techniques offer enormously different characteristics and, through the variation of various chemical techniques and conditions, a wide range of chemical and energetic properties may be attained. This may give the opportunity for the safe use of MICs as replacements for some conventional energetic materials in various applications, and may also enable us to study the effects when incorporating these MICs into energetic matrixes, as a promising and feasible research field.
{"title":"Review of Nano-thermites; a Pathway to Enhanced Energetic Materials","authors":"M. Zaky, A. Elbeih, T. Elshenawy","doi":"10.22211/CEJEM/134953","DOIUrl":"https://doi.org/10.22211/CEJEM/134953","url":null,"abstract":"Nano-thermites or metastable intermolecular composites (MICs) have been implemented into modern research on energetic materials as they offer much higher energy densities, higher rates of energy release, stability, and safety (lower sensitivity). This paper reviews several synthetic methods for MICs that have been well thought-out for energetic applications, advantages and disadvantages, as well as the characteristics of each manufacturing technique. The techniques presented include powder mixing, sol-gel, synthesis of MICs based on nano-porous silicon (Psi), sputtering, multilayer nano-foils and electrolytically plated carbon nano-materials for nano-thermite applications. These techniques offer enormously different characteristics and, through the variation of various chemical techniques and conditions, a wide range of chemical and energetic properties may be attained. This may give the opportunity for the safe use of MICs as replacements for some conventional energetic materials in various applications, and may also enable us to study the effects when incorporating these MICs into energetic matrixes, as a promising and feasible research field.","PeriodicalId":9679,"journal":{"name":"Central European Journal of Energetic Materials","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48670822","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}
M. Keshavarz, Seyyed Mohammad Hossein Hosseini, M. Karimi
This work introduces dynamic mechanical thermal analysis (DMTA) as an efficient method for the assessment of the shelf life of solid composite solid propellants in air and nitrogen atmospheres. The samples were aged at three temperatures 323.15, 333.15, and 343.15 K for 60, 120, and 180 days. The two different methods of Arrhenius and Berthelot were used to compare the effects of air and nitrogen atmospheres on the ageing of composite solid propellants. Damping (Tan δ) of composite solid propellants was used to determine the shelf life of the samples based on the loss of half of the physical property Tan δ (50% drop in damping). For the air atmosphere, the calculated activation energy for the degradation reactions of the samples was 86.26 kJ·mol–1. Both models, Arrhenius and Berthelot, confirmed that the shelf lives of the samples under the nitrogen atmosphere are more than four times those in an air atmosphere.
{"title":"Assessment of the Shelf Life of Composite Solid Propellants in Air and Nitrogen Atmospheres through Thermal Ageing","authors":"M. Keshavarz, Seyyed Mohammad Hossein Hosseini, M. Karimi","doi":"10.22211/CEJEM/134663","DOIUrl":"https://doi.org/10.22211/CEJEM/134663","url":null,"abstract":"This work introduces dynamic mechanical thermal analysis (DMTA) as an efficient method for the assessment of the shelf life of solid composite solid propellants in air and nitrogen atmospheres. The samples were aged at three temperatures 323.15, 333.15, and 343.15 K for 60, 120, and 180 days. The two different methods of Arrhenius and Berthelot were used to compare the effects of air and nitrogen atmospheres on the ageing of composite solid propellants. Damping (Tan δ) of composite solid propellants was used to determine the shelf life of the samples based on the loss of half of the physical property Tan δ (50% drop in damping). For the air atmosphere, the calculated activation energy for the degradation reactions of the samples was 86.26 kJ·mol–1. Both models, Arrhenius and Berthelot, confirmed that the shelf lives of the samples under the nitrogen atmosphere are more than four times those in an air atmosphere.","PeriodicalId":9679,"journal":{"name":"Central European Journal of Energetic Materials","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47534287","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}
Chemical time delay detonators are used widely in mine blasting applications. In order to achieve effective blasting, detonations must follow a precisely controlled timing sequence in a specified firing pattern. Silicon fuelbased pyrotechnic compositions are widely used in mining detonators and are well studied. However, some of these formulations are deemed to be problematic, as they contain heavy metals which are bio-accumulative and toxic to the environment. Therefore, there is need to explore alternative formulations which are suitable for these applications. Manganese-fueled systems are attractive due to their metallic properties and several oxidation states of the manganese fuel. This study focused on characterizing the burn properties of Mn/Bi2O3 compositions for slow to intermediate time delay applications. The compositions supported combustion in the 25 to 55 wt.% Mn range in an inert helium atmosphere. Burn rates between 2.5 and 11.2 mm·s–1 were recorded in open burn tests, whilst closed burn tests in glass tubes resulted in burn rates of 6.3 to 11.2 mm·s–1. Both X-ray diffraction analysis of the reaction products and thermodynamic simulations confirmed that MnO and Bi are the main reaction products, with unreacted Mn and Bi2O3 also being detected. This suggests that the dominant reaction for this composition is a simple thermite-type reaction.
{"title":"Performance of Mn/Bi2O3 Pyrotechnic Time Delay Compositions","authors":"S. Tichapondwa, Shasha Guo, W. Roux","doi":"10.22211/CEJEM/134798","DOIUrl":"https://doi.org/10.22211/CEJEM/134798","url":null,"abstract":"Chemical time delay detonators are used widely in mine blasting applications. In order to achieve effective blasting, detonations must follow a precisely controlled timing sequence in a specified firing pattern. Silicon fuelbased pyrotechnic compositions are widely used in mining detonators and are well studied. However, some of these formulations are deemed to be problematic, as they contain heavy metals which are bio-accumulative and toxic to the environment. Therefore, there is need to explore alternative formulations which are suitable for these applications. Manganese-fueled systems are attractive due to their metallic properties and several oxidation states of the manganese fuel. This study focused on characterizing the burn properties of Mn/Bi2O3 compositions for slow to intermediate time delay applications. The compositions supported combustion in the 25 to 55 wt.% Mn range in an inert helium atmosphere. Burn rates between 2.5 and 11.2 mm·s–1 were recorded in open burn tests, whilst closed burn tests in glass tubes resulted in burn rates of 6.3 to 11.2 mm·s–1. Both X-ray diffraction analysis of the reaction products and thermodynamic simulations confirmed that MnO and Bi are the main reaction products, with unreacted Mn and Bi2O3 also being detected. This suggests that the dominant reaction for this composition is a simple thermite-type reaction.","PeriodicalId":9679,"journal":{"name":"Central European Journal of Energetic Materials","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41800891","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 this work a new putty-like explosive containing 1,3,5-trinitro-1,3,5triazine (RDX) and polydimethylsiloxane (PDMS) was prepared and its properties were studied. The plasticity and the decomposition temperature of the explosive were determined. The sensitivity to friction, impact, shock wave and internal ignition were tested. The heats of combustion and explosion of the formulation were also measured. The diameter and critical layer as well as the detonation velocity of charges of different diameters were determined. The research results obtained were analyzed.
{"title":"Studies on the Properties of a Putty-like Explosive with a Silicone Binder","authors":"Karol Zalewski, Z. Chyłek, W. Trzciński","doi":"10.22211/CEJEM/135053","DOIUrl":"https://doi.org/10.22211/CEJEM/135053","url":null,"abstract":"In this work a new putty-like explosive containing 1,3,5-trinitro-1,3,5triazine (RDX) and polydimethylsiloxane (PDMS) was prepared and its properties were studied. The plasticity and the decomposition temperature of the explosive were determined. The sensitivity to friction, impact, shock wave and internal ignition were tested. The heats of combustion and explosion of the formulation were also measured. The diameter and critical layer as well as the detonation velocity of charges of different diameters were determined. The research results obtained were analyzed.","PeriodicalId":9679,"journal":{"name":"Central European Journal of Energetic Materials","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46954241","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}
Ke Wang, Hai-tao Huang, Huixiang Xu, Huan Li, Jun-qiang Li, X. Fan, W. Pang
Based on Energy Calculation Star program and molecular dynamic method, three designed 2,3-bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol tetranitrate-based (BHDBT) propellants are firstly reported and their physicochemical performance are investigated. Results suggest that compared with HMX-based and CL-20-based propellants, the specific impulses of all BHDBT-based propellants surpass or approximate 280 s, which indicates the latter have the potential to be high-energy propellants. The diffusion coefficient of plasticizers in BHDBT-based propellant decrease as the temperature reduces, and reduce in the order: Bu-NENA > TMETN > BTTN. The densities of all BHDBT-based propellants surpass or approximate 1.7 g/cm3. The comparison of elastic constants, Poisson’s ratios and K/G values indicates that the mechanical properties of three BHDBT-based propellants increase in the order (by plasticizer): Bu-NENA < TMETN < BTTN. The bond length analysis of C–NO2 and O–NO2 bond in BHDBT suggests that the former is the trigger bond in the BHDBT-based propellants, and the safety of BHDBT-based propellants and BHDBT crystal decreases in the order: GAP/BTTN/Al/BHDBT > GAP/Bu-NENA/Al/BHDBT ≈ GAP/TMETN/Al/BHDBT > BHDBT. In conclusion, GAP/BTTN/Al/BHDBT propellant has the potential to be a novel high-energy propellant.
{"title":"Theoretical Simulations on Physicochemical Performance of Novel High-energy BHDBT-based Propellants","authors":"Ke Wang, Hai-tao Huang, Huixiang Xu, Huan Li, Jun-qiang Li, X. Fan, W. Pang","doi":"10.22211/CEJEM/134652","DOIUrl":"https://doi.org/10.22211/CEJEM/134652","url":null,"abstract":"Based on Energy Calculation Star program and molecular dynamic method, three designed 2,3-bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol tetranitrate-based (BHDBT) propellants are firstly reported and their physicochemical performance are investigated. Results suggest that compared with HMX-based and CL-20-based propellants, the specific impulses of all BHDBT-based propellants surpass or approximate 280 s, which indicates the latter have the potential to be high-energy propellants. The diffusion coefficient of plasticizers in BHDBT-based propellant decrease as the temperature reduces, and reduce in the order: Bu-NENA > TMETN > BTTN. The densities of all BHDBT-based propellants surpass or approximate 1.7 g/cm3. The comparison of elastic constants, Poisson’s ratios and K/G values indicates that the mechanical properties of three BHDBT-based propellants increase in the order (by plasticizer): Bu-NENA < TMETN < BTTN. The bond length analysis of C–NO2 and O–NO2 bond in BHDBT suggests that the former is the trigger bond in the BHDBT-based propellants, and the safety of BHDBT-based propellants and BHDBT crystal decreases in the order: GAP/BTTN/Al/BHDBT > GAP/Bu-NENA/Al/BHDBT ≈ GAP/TMETN/Al/BHDBT > BHDBT. In conclusion, GAP/BTTN/Al/BHDBT propellant has the potential to be a novel high-energy propellant.","PeriodicalId":9679,"journal":{"name":"Central European Journal of Energetic Materials","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45604702","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}
This article considers aspects of the flow, rheology, and viscometry of guncotton pulp. It is substantiated that during production guncotton pulp is subjected to shear deformation, taking into account sliding over smooth surfaces, in the input zones of the dies, in the barrel, and on the crimped finned tube of the screw extruder. At the same time, the presence of shear stress in guncotton pulp has not been established. A rotational viscometer with a torque meter, which was developed during this research, enabled the presence of shear stress in guncotton pulp to be demonstrated. The values of the flow stress depend on the solvent content in the guncotton pulp; as this is decreased, the τ0 value increases. When the flow curve for the section from τ0 to τRmax was constructed, the flow curves of the guncotton pulp were described by the Herschel-Bulkley equation. The flow curves of guncotton pulp obtained on corrugated capillaries of different sizes are non-invariant and depend on the magnitude of the deformation of the guncotton pulp in the capillaries. Guncotton pulp flows in a narrow range of pressures and deformations.
{"title":"Shear Flow of Guncotton Pulp","authors":"V. Banishevsky, R. Zakusylo, D. Zakusylo","doi":"10.22211/CEJEM/134904","DOIUrl":"https://doi.org/10.22211/CEJEM/134904","url":null,"abstract":"This article considers aspects of the flow, rheology, and viscometry of guncotton pulp. It is substantiated that during production guncotton pulp is subjected to shear deformation, taking into account sliding over smooth surfaces, in the input zones of the dies, in the barrel, and on the crimped finned tube of the screw extruder. At the same time, the presence of shear stress in guncotton pulp has not been established. A rotational viscometer with a torque meter, which was developed during this research, enabled the presence of shear stress in guncotton pulp to be demonstrated. The values of the flow stress depend on the solvent content in the guncotton pulp; as this is decreased, the τ0 value increases. When the flow curve for the section from τ0 to τRmax was constructed, the flow curves of the guncotton pulp were described by the Herschel-Bulkley equation. The flow curves of guncotton pulp obtained on corrugated capillaries of different sizes are non-invariant and depend on the magnitude of the deformation of the guncotton pulp in the capillaries. Guncotton pulp flows in a narrow range of pressures and deformations.","PeriodicalId":9679,"journal":{"name":"Central European Journal of Energetic Materials","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49537177","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}
{"title":"The Shooting Tests of Target Perforating Ability, Performed on Cast Concrete Cylinders","authors":"Ł. Habera, Kamil Hebda, P. Koślik, T. Sałaciński","doi":"10.22211/cejem/132066","DOIUrl":"https://doi.org/10.22211/cejem/132066","url":null,"abstract":"","PeriodicalId":9679,"journal":{"name":"Central European Journal of Energetic Materials","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47535557","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}
K. D. B. Yamajala, Hema Singh, Ramesh Kurva, M. Maurya, Shaibal Banerjee
{"title":"Composite Propellant Formulation of Poly (16-, 32- and 64-) Azido Dendritic Esters as Energetic Plasticizer and Evaluation of Properties","authors":"K. D. B. Yamajala, Hema Singh, Ramesh Kurva, M. Maurya, Shaibal Banerjee","doi":"10.22211/cejem/131235","DOIUrl":"https://doi.org/10.22211/cejem/131235","url":null,"abstract":"","PeriodicalId":9679,"journal":{"name":"Central European Journal of Energetic Materials","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42945413","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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