Pub Date : 2025-11-01Epub Date: 2025-08-22DOI: 10.1016/j.tca.2025.180105
Wenke Zhang, Jianzhong Liu, Haiou Wang, Xueqin Liao, Jianren Fan
Aluminum (Al) combustion in CO2 was investigated to assess carbon sequestration potential. Theoretical and experimental results identified C(s), Al4C3(s), and CO(g) as primary products, with C(s) formation being most thermodynamically favorable. Al oxidation in CO2 proceeded through three stages, with the second stage (activation energy: 260–268 kJ·mol⁻¹) exhibiting the highest reactivity. Kinetic analysis indicated an Anti-Jander/D1 mechanism for this dominant stage. Reducing particle size from 25 μm to 0.1 μm at 0.1 MPa shortened ignition delay by 664 ms and increased combustion temperature by 847 K. Characterization confirmed carbon incorporation in products (Al2O3/Al4C3) and demonstrated enhanced combustion efficiency and carbon fixation with smaller particles or higher pressures. These findings provide critical insights for Martian in-situ resource utilization and carbon capture technologies.
{"title":"Quantitative assessment of combustion characteristics and carbon sequestration potential of Al/CO2 heterogeneous system","authors":"Wenke Zhang, Jianzhong Liu, Haiou Wang, Xueqin Liao, Jianren Fan","doi":"10.1016/j.tca.2025.180105","DOIUrl":"10.1016/j.tca.2025.180105","url":null,"abstract":"<div><div>Aluminum (Al) combustion in CO<sub>2</sub> was investigated to assess carbon sequestration potential. Theoretical and experimental results identified C(s), Al<sub>4</sub>C<sub>3</sub>(s), and CO(g) as primary products, with C(s) formation being most thermodynamically favorable. Al oxidation in CO<sub>2</sub> proceeded through three stages, with the second stage (activation energy: 260–268 kJ·mol⁻¹) exhibiting the highest reactivity. Kinetic analysis indicated an Anti-Jander/D1 mechanism for this dominant stage. Reducing particle size from 25 μm to 0.1 μm at 0.1 MPa shortened ignition delay by 664 ms and increased combustion temperature by 847 K. Characterization confirmed carbon incorporation in products (Al<sub>2</sub>O<sub>3</sub>/Al<sub>4</sub>C<sub>3</sub>) and demonstrated enhanced combustion efficiency and carbon fixation with smaller particles or higher pressures. These findings provide critical insights for Martian in-situ resource utilization and carbon capture technologies.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180105"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-02DOI: 10.1016/j.tca.2025.180099
Alireza Aghili , Andrei A. Stolov , Amir Hossein Shabani
This study introduces a methodology for determining the kinetic parameters of condensed phase reactions under nonisothermal conditions by factorizing the reaction rate into a temperature-dependent rate constant and a conversion function. The conversion function is approximated using either the discrete cosine transform (DCT) or the Chebyshev series expansion (CSE) reaction models. The proposed method is applicable to both simple and complex reactions. Notably, for the first time, this approach enables the accurate estimation of the conversion function and pre-exponential factor for complex multistage reactions characterized by multiple peaks in their reaction rate profiles. The developed technique was applied to both simulated reactions and experimental data related to the thermal decomposition of polymer coating from a commercial optical fiber. Additionally, GNU Octave/MATLAB codes have been provided to facilitate the application of new methodology to user-specific datasets.
{"title":"Determination of the kinetic parameters of condensed phase reactions under nonisothermal conditions","authors":"Alireza Aghili , Andrei A. Stolov , Amir Hossein Shabani","doi":"10.1016/j.tca.2025.180099","DOIUrl":"10.1016/j.tca.2025.180099","url":null,"abstract":"<div><div>This study introduces a methodology for determining the kinetic parameters of condensed phase reactions under nonisothermal conditions by factorizing the reaction rate into a temperature-dependent rate constant and a conversion function. The conversion function is approximated using either the discrete cosine transform (DCT) or the Chebyshev series expansion (CSE) reaction models. The proposed method is applicable to both simple and complex reactions. Notably, for the first time, this approach enables the accurate estimation of the conversion function and pre-exponential factor for complex multistage reactions characterized by multiple peaks in their reaction rate profiles. The developed technique was applied to both simulated reactions and experimental data related to the thermal decomposition of polymer coating from a commercial optical fiber. Additionally, GNU Octave/MATLAB codes have been provided to facilitate the application of new methodology to user-specific datasets.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180099"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
NH4H2PO4 (ADP) and Ca(H2PO4)2 (CPM) were used to reduce potassium emissions in rice straw ash (RSA), but the interactions between additives and RSA and the resulting transformations were unclear. In this work, thermogravimetric analysis identified temperature windows for interactions between the additives and RSA. 31PNMR and XRD distinguished the resulting phosphate species. Potassium emissions were reduced by 9.26 kg/t with ADP and 4.77 kg/t with CPM. Additives increased both NH₄Ac-soluble and insoluble potassium fractions. The conversion of KCl to water-soluble K-phosphate occurred between 200-450 °C, a range previously overlooked due to only minor changes in water-soluble fraction up to 700 °C. NH₄Ac-soluble potassium species included K₄Ca(PO₄)₂ and K₂CaP₂O₇, while insoluble species included K-aluminosilicate, K-silicate and Ca₉MgK(PO₄)₇. These solubility distinctions provide new insights for understanding the transformation of P-containing complexes, though further investigation into the thermodynamic and kinetic factors governing these formations is needed.
{"title":"The properties and transformation of related products for potassium fixing in the interactions between the rice straw ash and NH4H2PO4 and Ca(H2PO4)2","authors":"Weixue Xiang, Tinggui Yan, Yunqi Wu, Peixu Zhu, Nanxi Luo, Banglian Tang, Miao Luo","doi":"10.1016/j.tca.2025.180150","DOIUrl":"10.1016/j.tca.2025.180150","url":null,"abstract":"<div><div>NH<sub>4</sub>H<sub>2</sub>PO<sub>4</sub> (ADP) and Ca(H<sub>2</sub>PO<sub>4</sub>)<sub>2</sub> (CPM) were used to reduce potassium emissions in rice straw ash (RSA), but the interactions between additives and RSA and the resulting transformations were unclear. In this work, thermogravimetric analysis identified temperature windows for interactions between the additives and RSA. <sup>31</sup>PNMR and XRD distinguished the resulting phosphate species. Potassium emissions were reduced by 9.26 kg/t with ADP and 4.77 kg/t with CPM. Additives increased both NH₄Ac-soluble and insoluble potassium fractions. The conversion of KCl to water-soluble K-phosphate occurred between 200-450 °C, a range previously overlooked due to only minor changes in water-soluble fraction up to 700 °C. NH₄Ac-soluble potassium species included K₄Ca(PO₄)₂ and K₂CaP₂O₇, while insoluble species included K-aluminosilicate, K-silicate and Ca₉MgK(PO₄)₇. These solubility distinctions provide new insights for understanding the transformation of P-containing complexes, though further investigation into the thermodynamic and kinetic factors governing these formations is needed.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180150"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-29DOI: 10.1016/j.tca.2025.180144
A.V. Lazarev , T.A. Semenov
The influence of instrumental conditions (heating rate and sample size) on the accuracy of determining the Arrhenius parameters (activation energy E and pre-exponential factor k0) using the model of non-isothermal decomposition in a first-order reaction was investigated. A criterion was obtained that provides a kinetic control regime in the experiment (equality of sample and program heating temperatures), allowing the processing of experimental data by traditional methods. Based on this criterion, a real experiment on the decomposition of hydrogen trioxide H2O3 is selected. The obtained kinetic parameters for this reaction were then utilized in a model experiment to assess the impact of the chemical and thermodynamic properties of the sample, heat transfer, and experimental instrumental conditions (sample size and programmed heating rate) on the precision of determining the kinetic parameters.
{"title":"Model of experiment in non-isothermal kinetics of thermal decomposition reaction","authors":"A.V. Lazarev , T.A. Semenov","doi":"10.1016/j.tca.2025.180144","DOIUrl":"10.1016/j.tca.2025.180144","url":null,"abstract":"<div><div>The influence of instrumental conditions (heating rate and sample size) on the accuracy of determining the Arrhenius parameters (activation energy E and pre-exponential factor k<sub>0</sub>) using the model of non-isothermal decomposition in a first-order reaction was investigated. A criterion was obtained that provides a kinetic control regime in the experiment (equality of sample and program heating temperatures), allowing the processing of experimental data by traditional methods. Based on this criterion, a real experiment on the decomposition of hydrogen trioxide H<sub>2</sub>O<sub>3</sub> is selected. The obtained kinetic parameters for this reaction were then utilized in a model experiment to assess the impact of the chemical and thermodynamic properties of the sample, heat transfer, and experimental instrumental conditions (sample size and programmed heating rate) on the precision of determining the kinetic parameters.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180144"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-29DOI: 10.1016/j.tca.2025.180145
Mirko Schoenitz, Edward L Dreizin
Viton A, when used as a binder in energetic formulations, typically decomposes on millisecond time scales. Characterization of this reaction, however, has been traditionally carried out using conventional thermal analysis (TA), on time scales of minutes to hours. Here, the decomposition of thin films of Viton A in an inert environment is studied using fast scanning calorimetry with heating rates up to 20,000 K/s. Thus, the decomposition occurs within tens of milliseconds. The measurements are complemented by visual observation of the sensor, making it possible to correlate details of the heat flow signal with processes occurring at different parts of the sensor. Conventional TA measurements are also performed. In both fast and conventional TA experiments, the heat flow signal does not return to an identifiable baseline, making interpretation of the results challenging. Nevertheless, it is observed that the volatilization is accompanied by an exothermic heat effect of 150.3 ± 16.7 J/g that slightly precedes the removal of the material, or mass loss in conventional thermal analysis. Kinetic processing shows an activation energy of 218 ± 2 kJ/mol, broadly consistent with literature data.
{"title":"Rapid thermal decomposition of Viton A","authors":"Mirko Schoenitz, Edward L Dreizin","doi":"10.1016/j.tca.2025.180145","DOIUrl":"10.1016/j.tca.2025.180145","url":null,"abstract":"<div><div>Viton A, when used as a binder in energetic formulations, typically decomposes on millisecond time scales. Characterization of this reaction, however, has been traditionally carried out using conventional thermal analysis (TA), on time scales of minutes to hours. Here, the decomposition of thin films of Viton A in an inert environment is studied using fast scanning calorimetry with heating rates up to 20,000 K/s. Thus, the decomposition occurs within tens of milliseconds. The measurements are complemented by visual observation of the sensor, making it possible to correlate details of the heat flow signal with processes occurring at different parts of the sensor. Conventional TA measurements are also performed. In both fast and conventional TA experiments, the heat flow signal does not return to an identifiable baseline, making interpretation of the results challenging. Nevertheless, it is observed that the volatilization is accompanied by an exothermic heat effect of 150.3 ± 16.7 J/g that slightly precedes the removal of the material, or mass loss in conventional thermal analysis. Kinetic processing shows an activation energy of 218 ± 2 kJ/mol, broadly consistent with literature data.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180145"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-08-20DOI: 10.1016/j.tca.2025.180108
Gyeong Cheol Yu , Na Young Jang , Hyeon Ji Kim , Jong Hee Kim , Jun Mo Koo , Seung Goo Lee
The aerospace industry is increasingly focused on developing thermal protection systems (TPS) to safeguard spacecraft from extreme heat during high-speed flight and atmospheric re-entry. Phenolic resin (PR) is commonly used in TPS applications because it forms a carbon-rich char layer during thermal decomposition, which provides excellent thermal resistance, flame retardancy, and structural stability. However, PR can decompose in high-temperature environments that contain oxygen, limiting its long-term effectiveness. To address this limitation, inorganic additives such as boric acid (BA) have been introduced to enhance the thermal and flame-retardant properties of PR. BA assists in forming a boron-containing carbon layer that suppresses flame spread and improves thermal resistance. SC-1008 phenolic resin was used as the matrix, and BA were added to prepare composites, which were then tested for thermal, mechanical, and flame-retardant performance. The results indicated that increasing the BA content significantly improved the thermal stability and flame retardancy of the PR while maintaining mechanical performance. This enhancement is attributed to the synergistic effects of BA, which promotes the formation of protective carbides and reduces flammability. Overall, the PR/BA composite material shows significant potential in aerospace applications as an advanced TPS material, providing improved protection under extreme thermal conditions during space missions.
{"title":"Boric acid-containing phenolic resin composites for ablative thermal protection system","authors":"Gyeong Cheol Yu , Na Young Jang , Hyeon Ji Kim , Jong Hee Kim , Jun Mo Koo , Seung Goo Lee","doi":"10.1016/j.tca.2025.180108","DOIUrl":"10.1016/j.tca.2025.180108","url":null,"abstract":"<div><div>The aerospace industry is increasingly focused on developing thermal protection systems (TPS) to safeguard spacecraft from extreme heat during high-speed flight and atmospheric re-entry. Phenolic resin (PR) is commonly used in TPS applications because it forms a carbon-rich char layer during thermal decomposition, which provides excellent thermal resistance, flame retardancy, and structural stability. However, PR can decompose in high-temperature environments that contain oxygen, limiting its long-term effectiveness. To address this limitation, inorganic additives such as boric acid (BA) have been introduced to enhance the thermal and flame-retardant properties of PR. BA assists in forming a boron-containing carbon layer that suppresses flame spread and improves thermal resistance. SC-1008 phenolic resin was used as the matrix, and BA were added to prepare composites, which were then tested for thermal, mechanical, and flame-retardant performance. The results indicated that increasing the BA content significantly improved the thermal stability and flame retardancy of the PR while maintaining mechanical performance. This enhancement is attributed to the synergistic effects of BA, which promotes the formation of protective carbides and reduces flammability. Overall, the PR/BA composite material shows significant potential in aerospace applications as an advanced TPS material, providing improved protection under extreme thermal conditions during space missions.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180108"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144906945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Given the high selectivity of dicyclohexano-18-crown-6 (DCH18C6) crown ether toward strontium, there is growing interest in its use in radiochemical processes, including as a solid-phase extractant (SPE). In this work, differential scanning calorimetry, gas chromatography-mass spectrometry, and infrared (IR) spectroscopy were used to characterize the processes occurring during heating of SPE-DCH18C6, the crown ether DCH18C6, and the inert styrene-divinylbenzene matrix Porolas-T. Samples of SPE-DCH18C6 were prepared by impregnating Porolas-T with a solution of 0.01 mol/L DCH18C6 in chloroform. As a result of the research, it was found that upon heating in inert atmosphere SPE-DCH18C6 undergoes endothermic decomposition in the temperature range 320-480 °C (593-753 K), as does Porolas-T. The SPE and inert matrix have a similar set of gaseous decomposition products, which includes benzene and a number of its derivatives. In oxidizing atmosphere, SPE-DCH18C6 decomposes exothermically in several stages at temperatures of 180-580 °C (453-853 K) with a total specific heat release of about 104 J/g. The effect of nitric acid on the thermal effects and destruction products of the sample was assessed. A decrease in the intensity of the crown ether bands in the IR spectra was established for the SPE after contact with nitric acid using IR spectroscopy. SPE-DCH18C6 remains thermally stable up to 100 °C and can be used for strontium extraction at radiochemical facilities.
{"title":"Thermal decomposition of the solid-phase extractant based on dicyclohexano-18-crown-6 and determination of gaseous products of its destruction","authors":"A.M. Koscheeva , K.V. Shelamov , I.A. Bolshakova , A.M. Koshcheev , A.V. Ananiev , A.V. Rodin","doi":"10.1016/j.tca.2025.180126","DOIUrl":"10.1016/j.tca.2025.180126","url":null,"abstract":"<div><div>Given the high selectivity of dicyclohexano-18-crown-6 (DCH18C6) crown ether toward strontium, there is growing interest in its use in radiochemical processes, including as a solid-phase extractant (SPE). In this work, differential scanning calorimetry, gas chromatography-mass spectrometry, and infrared (IR) spectroscopy were used to characterize the processes occurring during heating of SPE-DCH18C6, the crown ether DCH18C6, and the inert styrene-divinylbenzene matrix Porolas-T. Samples of SPE-DCH18C6 were prepared by impregnating Porolas-T with a solution of 0.01 mol/L DCH18C6 in chloroform. As a result of the research, it was found that upon heating in inert atmosphere SPE-DCH18C6 undergoes endothermic decomposition in the temperature range 320-480 °C (593-753 K), as does Porolas-T. The SPE and inert matrix have a similar set of gaseous decomposition products, which includes benzene and a number of its derivatives. In oxidizing atmosphere, SPE-DCH18C6 decomposes exothermically in several stages at temperatures of 180-580 °C (453-853 K) with a total specific heat release of about 10<sup>4</sup> J/g. The effect of nitric acid on the thermal effects and destruction products of the sample was assessed. A decrease in the intensity of the crown ether bands in the IR spectra was established for the SPE after contact with nitric acid using IR spectroscopy. SPE-DCH18C6 remains thermally stable up to 100 °C and can be used for strontium extraction at radiochemical facilities.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180126"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-10-08DOI: 10.1016/j.tca.2025.180153
Wenyu Xu , Chunlan Jiang , Zaicheng Wang , Ye Zhang , Yubiao Wei , Wenxiang Li , Jiankui Guo
Novel nitrogen-rich ionic salt energetic material, 5,5′-bitetrazole-1,1′-diol dihydroxylamine salt (TKX-50) has been widely concerned in safety ammunition field. In this paper, non-isothermal thermal analysis and adiabatic ARC experiments are conducted on TKX-50-based multi-component explosive TMCE (TKX-50/CL-20/AP/Al/binder=15/10/32/37/6), and the thermal decomposition characteristics of TMCE are explored. The results indicate that the initial thermal decomposition temperature and the peak decomposition temperatures of TMCE drop dramatically due to the component synergistic interaction. Confinement and oxygen-enriched environments facilitate thermal runaway in TMCE. Based on thermal analysis findings, the Self-Accelerating Decomposition Temperature (SADT) of TMCE was calculated. The heating process of the small-scale cook-off device was calculated and experimentally validated with reaction time errors below 3%. These findings enable thermal safety prediction for TMCE-loaded warheads and provide critical references for engineering applications and formulation design of TKX-50-based energetic materials.
{"title":"Study on the thermal decomposition characteristics and thermal safety of TKX-50-based multicomponent energetic materials","authors":"Wenyu Xu , Chunlan Jiang , Zaicheng Wang , Ye Zhang , Yubiao Wei , Wenxiang Li , Jiankui Guo","doi":"10.1016/j.tca.2025.180153","DOIUrl":"10.1016/j.tca.2025.180153","url":null,"abstract":"<div><div>Novel nitrogen-rich ionic salt energetic material, 5,5′-bitetrazole-1,1′-diol dihydroxylamine salt (TKX-50) has been widely concerned in safety ammunition field. In this paper, non-isothermal thermal analysis and adiabatic ARC experiments are conducted on TKX-50-based multi-component explosive TMCE (TKX-50/CL-20/AP/Al/binder=15/10/32/37/6), and the thermal decomposition characteristics of TMCE are explored. The results indicate that the initial thermal decomposition temperature and the peak decomposition temperatures of TMCE drop dramatically due to the component synergistic interaction. Confinement and oxygen-enriched environments facilitate thermal runaway in TMCE. Based on thermal analysis findings, the Self-Accelerating Decomposition Temperature (SADT) of TMCE was calculated. The heating process of the small-scale cook-off device was calculated and experimentally validated with reaction time errors below 3%. These findings enable thermal safety prediction for TMCE-loaded warheads and provide critical references for engineering applications and formulation design of TKX-50-based energetic materials.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180153"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-08-26DOI: 10.1016/j.tca.2025.180115
Askar K. Gatiatulin, Mukhammet N. Gabdulkhaev, Samat R. Tagirov, Radik A. Larionov, Marat A. Ziganshin, Valery V. Gorbatchuk
The fusion thermodynamics of native cyclodextrins was studied, which provides a basis for modelling their behavior in various applications. The fusion enthalpies and entropies of high-temperature polymorphs of α-cyclodextrin and β-cyclodextrin were determined using fast scanning calorimetry with a heating rate up to 40,000 K s–1. A high-temperature polymorph of anhydrous α-cyclodextrin (polymorph III) was obtained and for the first time characterized using powder X-ray diffraction and thermal analysis. The comparison of experimental fusion enthalpies of native cyclodextrins with the data of theoretical additive-constitutive model shows a good agreement for β-cyclodextrin and previously studied γ-cyclodextrin. The experimental data on fusion entropy were used to estimate the flexibility of cyclodextrin molecules in liquid state. The flexibility of β-cyclodextrin and γ-cyclodextrin is close to the theoretical values for corresponding non-macrocyclic oligosaccharides, while as α-cyclodextrin molecule remains rigid in liquid phase. This is a factor in favor of the higher α-cyclodextrin affinity for guests that can be accommodated in its cavity.
研究了天然环糊精的熔合热力学，为其在各种应用中的行为建模提供了依据。采用快速扫描量热法测定了α-环糊精和β-环糊精高温多晶的熔合焓和熵，加热速率为40000 K s-1。获得了无水α-环糊精的高温晶型（晶型III），并首次利用粉末x射线衍射和热分析对其进行了表征。将天然环糊精的实验融合焓与理论加性本构模型的数据进行了比较，结果表明β-环糊精与前人研究的γ-环糊精具有较好的一致性。利用聚变熵的实验数据估计了环糊精分子在液态下的柔韧性。β-环糊精和γ-环糊精的柔度接近于相应非大环低聚糖的理论值，而α-环糊精分子在液相中保持刚性。这是有利于α-环糊精对可容纳在其腔内的客体具有较高亲和力的一个因素。
{"title":"Fusion thermodynamics of native cyclodextrins","authors":"Askar K. Gatiatulin, Mukhammet N. Gabdulkhaev, Samat R. Tagirov, Radik A. Larionov, Marat A. Ziganshin, Valery V. Gorbatchuk","doi":"10.1016/j.tca.2025.180115","DOIUrl":"10.1016/j.tca.2025.180115","url":null,"abstract":"<div><div>The fusion thermodynamics of native cyclodextrins was studied, which provides a basis for modelling their behavior in various applications. The fusion enthalpies and entropies of high-temperature polymorphs of α-cyclodextrin and β-cyclodextrin were determined using fast scanning calorimetry with a heating rate up to 40,000 K s<sup>–1</sup>. A high-temperature polymorph of anhydrous α-cyclodextrin (polymorph III) was obtained and for the first time characterized using powder X-ray diffraction and thermal analysis. The comparison of experimental fusion enthalpies of native cyclodextrins with the data of theoretical additive-constitutive model shows a good agreement for β-cyclodextrin and previously studied γ-cyclodextrin. The experimental data on fusion entropy were used to estimate the flexibility of cyclodextrin molecules in liquid state. The flexibility of β-cyclodextrin and γ-cyclodextrin is close to the theoretical values for corresponding non-macrocyclic oligosaccharides, while as α-cyclodextrin molecule remains rigid in liquid phase. This is a factor in favor of the higher α-cyclodextrin affinity for guests that can be accommodated in its cavity.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180115"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144917851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-03DOI: 10.1016/j.tca.2025.180133
F. Spini , I. Marzorati , P. Bettini , A.M. Grande
Disposal of End-of-Life (EoL) thermoset composites, difficult to recycle due to polymer crosslinked structure, presents a significant challenge. Development of thermoset polymers with increased recyclability, self-healing, and reprocessability offers a promising solution for managing composite waste and extending component lifetime. Vitrimers, based on covalent adaptable networks (CANs) that rearrange their topology via reversible exchange reactions, are particularly promising.
Recent research has shown that varying vitrimers stoichiometry can impact properties such as dissolution capability, potentially enhancing recyclability. This study explores the effects of stoichiometry variation on the thermomechanical properties and cure kinetics of epoxy vitrimers incorporating 4-aminophenyl disulfide (4-AFD) as hardener. Knowledge regarding the progression of crosslinking for both stoichiometric and non-stoichiometric mixtures is critical for optimizing processes and predicting behaviour at different curing temperatures.
Vyazovkin’s approach emerged as the most suitable for analysing cure kinetics among the different methods. It revealed that the non-stoichiometric formulation with hardener excess maintained nearly constant activation energy, suggesting that the cure mechanism is primarily driven by interactions between primary amines and epoxy groups. This reduces the availability of epoxy groups for tertiary amine formation, resulting in a less dense network, lower storage modulus, and decreased Tg, as confirmed by DMA and DSC results.
{"title":"Cure kinetics of aromatic disulfide epoxy vitrimer: influence of epoxy/amine stoichiometry","authors":"F. Spini , I. Marzorati , P. Bettini , A.M. Grande","doi":"10.1016/j.tca.2025.180133","DOIUrl":"10.1016/j.tca.2025.180133","url":null,"abstract":"<div><div>Disposal of End-of-Life (EoL) thermoset composites, difficult to recycle due to polymer crosslinked structure, presents a significant challenge. Development of thermoset polymers with increased recyclability, self-healing, and reprocessability offers a promising solution for managing composite waste and extending component lifetime. Vitrimers, based on covalent adaptable networks (CANs) that rearrange their topology via reversible exchange reactions, are particularly promising.</div><div>Recent research has shown that varying vitrimers stoichiometry can impact properties such as dissolution capability, potentially enhancing recyclability. This study explores the effects of stoichiometry variation on the thermomechanical properties and cure kinetics of epoxy vitrimers incorporating 4-aminophenyl disulfide (4-AFD) as hardener. Knowledge regarding the progression of crosslinking for both stoichiometric and non-stoichiometric mixtures is critical for optimizing processes and predicting behaviour at different curing temperatures.</div><div>Vyazovkin’s approach emerged as the most suitable for analysing cure kinetics among the different methods. It revealed that the non-stoichiometric formulation with hardener excess maintained nearly constant activation energy, suggesting that the cure mechanism is primarily driven by interactions between primary amines and epoxy groups. This reduces the availability of epoxy groups for tertiary amine formation, resulting in a less dense network, lower storage modulus, and decreased T<sub>g</sub>, as confirmed by DMA and DSC results.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"753 ","pages":"Article 180133"},"PeriodicalIF":3.5,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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