Thermochimica Acta最新文献_第3页

Degradation pathways of Tadalafil: A thermoanalytical study.

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-15 DOI: 10.1016/j.tca.2025.179955

Francisco V.B. Nascimento , Ana P.G. Ferreira , Caroline Gaglieri , Aniele de Moura , Éder T.G. Cavalheiro

{"title":"Degradation pathways of Tadalafil: A thermoanalytical study.","authors":"Francisco V.B. Nascimento , Ana P.G. Ferreira , Caroline Gaglieri , Aniele de Moura , Éder T.G. Cavalheiro","doi":"10.1016/j.tca.2025.179955","DOIUrl":"10.1016/j.tca.2025.179955","url":null,"abstract":"<div><div>Tadalafil (TAD) is one of the most marketed farmaceuticals against erectile dysfunction, due to its large use worldwide it is interesting to understand different aspects regarding this pharmaceutical active ingredient. Thus, in the present study, thermal behavior of TAD was investigated by simultaneous thermogravimetry-differential thermal analysis (TGA-DTA), differential scanning calorimetry (DSC), hot stage microscopy (HSM) and evolved gas analysis using thermogravimetry coupled to vibrational infrared spectroscopy (TGA-FTIR). In addition kinetics of thermal decomposition of the drug was evaluated by non-isothermal kinetic. In atmospheres of N<sub>2</sub> and air, TAD, decomposed in different ways in N<sub>2</sub> and air atmospheres. DSC curves presented an endothermic event related to the melting of the sample at T<em><sub>onset</sub></em> = 576 K in the first heating, with no evidence of crystallization under the conditions used here. TGA-FTIR revealed that the thermal decomposition of TAD starts with releasing of 1,3-benzodioxole, carbon monoxide, and propyl isocyanate. The decomposition of the latter results in carbon dioxide and ammonia, which were identified in the gaseous phase and were not directly products from TAD, but by-products from propyl isocyanate. In the HSM, it was possible to observe the complete decomposition of TAD at 573 K, corroborating the results observed in TGA/DTG/DTA and DSC. According to these results, a thermal decomposition mechanism was proposed for TAD. Non-isothermal kinetic studies suggested two consecutive processes, which resulted in just one mass loss in the TGA curve: F1 (E<sub>a</sub> = 174, logA = 12.3) and C1 (135 kJ mol<sup>−1</sup>), 8.3 (1 s<sup>−1</sup>).</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"747 ","pages":"Article 179955"},"PeriodicalIF":3.1,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437297","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}

引用次数: 0

Thermal oxidative degradation of cyanate- and amine-cured epoxy resins: Experiment and ReaxFF simulation

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-11 DOI: 10.1016/j.tca.2025.179949

Yoshiaki Kawagoe , Gota Kikugawa , Shohei Komori , Keiichi Shirasu , Tomonaga Okabe

{"title":"Thermal oxidative degradation of cyanate- and amine-cured epoxy resins: Experiment and ReaxFF simulation","authors":"Yoshiaki Kawagoe , Gota Kikugawa , Shohei Komori , Keiichi Shirasu , Tomonaga Okabe","doi":"10.1016/j.tca.2025.179949","DOIUrl":"10.1016/j.tca.2025.179949","url":null,"abstract":"<div><div>Thermal oxidative degradation behaviors of epoxy resin cured with cyanate ester and conventional amine are experimentally evaluated in terms of heat resistance and flame retardancy, and the degradation mechanisms are further investigated using ReaxFF molecular dynamics simulations. Thermogravimetric analysis revealed that both resins exhibit multi-step decomposition behavior, with the cyanate-cured resin showing nearly double the residual weight (char formation) compared to the amine-cured resin. ReaxFF thermal degradation simulations of a fully cured resin model, with and without oxygen, and fragmentation models were performed to elucidate the heat resistance properties associated with different molecular structures. The experimental and simulation results suggest that the degradation follows a two-step process: the first stage involves pyrolysis of the main chain, and the second stage involves oxidation of the resulting products. The high heat resistance of the triazine ring in the cyanate-cured resin delays the transition to the second stage of degradation, resulting in high thermal oxidation resistance.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"747 ","pages":"Article 179949"},"PeriodicalIF":3.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experiment and mechanism of explosion suppression thermal properties of multicomponent powder

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-09 DOI: 10.1016/j.tca.2025.179953

Rongkun Pan , Chensheng Wang , Qingsheng Zhang , Chenzhuo Song , Chang Lu , Ligang Zheng , Bei Pei , Lei Chen

{"title":"Experiment and mechanism of explosion suppression thermal properties of multicomponent powder","authors":"Rongkun Pan , Chensheng Wang , Qingsheng Zhang , Chenzhuo Song , Chang Lu , Ligang Zheng , Bei Pei , Lei Chen","doi":"10.1016/j.tca.2025.179953","DOIUrl":"10.1016/j.tca.2025.179953","url":null,"abstract":"<div><div>In this paper, staged thermal characteristic experiments were conducted on commonly used powder explosion suppressants using a high-precision C600 microcalorimeter. The thermal decomposition process was divided into three stages, and a comprehensive analysis was carried out on the thermal flow curves, dHF, initial heat flow value H<sub>0</sub>, minimum heat flow value H<sub>min</sub>, characteristic points, and heat absorption amount Q of twelve powder explosion suppressants, including attapulgite and montmorillonite. The results indicate that carbamide has the smallest minimum heat flow value H<sub>min</sub> during powder thermal decomposition, while CaCO<sub>3</sub> has the largest minimum heat flow value H<sub>min</sub>. Carbamide exhibited the highest overall heat absorption amount, while NaCl showed the lowest overall heat absorption amount. The mechanism of inhibiting methane explosion with different powder suppressors was analyzed by comparing the pyrolysis experiment results. The conclusions of this study can serve as a theoretical foundation for the rational selection of powder explosion suppressors, enhancing their utilization rate, and improving their explosion suppression effectiveness.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"746 ","pages":"Article 179953"},"PeriodicalIF":3.1,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403568","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}

引用次数: 0

Thermal analysis and characterization of cast 6061 aluminum alloy microstructures with elevated iron content

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-06 DOI: 10.1016/j.tca.2025.179951

Mark A. Whitney , Haiou Jin , Mary A. Wells , Michael J. Benoit

{"title":"Thermal analysis and characterization of cast 6061 aluminum alloy microstructures with elevated iron content","authors":"Mark A. Whitney , Haiou Jin , Mary A. Wells , Michael J. Benoit","doi":"10.1016/j.tca.2025.179951","DOIUrl":"10.1016/j.tca.2025.179951","url":null,"abstract":"<div><div>When considering the recycling of aluminum alloys, one of the most pervasive impurity elements is iron. In the aluminum-magnesium-silicon system, the presence of iron can lead to the formation of a number of intermetallic phases in the microstructure, some of which can be quite deleterious due to their associated morphology. Since magnesium and silicon are responsible for the ageing response of 6xxx-series aluminum alloys, it is important to understand the phase formations that occur and consume these elements due to the addition of recycling impurities. Thermal analysis can be a beneficial tool in determining the influence of composition on phase formation, and the various stages of alloy solidification. The present study uses thermal analysis testing and microstructure characterization to assess the influence of iron impurity content on the melting and solidification behaviour of a model 6061 cast aluminum alloy. Using differential scanning calorimetry, the melting of eutectics present in the as-cast microstructures was measured; and coupled with peak deconvolution, the influence of iron on the presence of binary and ternary eutectics involving silicon, Mg<sub>2</sub>Si, α-AlFeSi and Al<sub>3</sub>Fe was determined. During controlled cooling, the influence of iron on temperatures corresponding to critical stages of solidification were determined and it was observed that the addition of 1 wt percent iron to the 6061 aluminum alloy caused a delay in the observed aluminum dendrite coherency, but that an earlier dendrite coherency point was established through the bridging of growing aluminum dendrites via the formation of Al<sub>3</sub>Fe intermetallic phase with aluminum.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"746 ","pages":"Article 179951"},"PeriodicalIF":3.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Kinetics of thermal decomposition and hydrogen reduction of Cobalt compounds: A review

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-06 DOI: 10.1016/j.tca.2025.179952

Sonja Pöyhtäri , Eetu-Pekka Heikkinen , Anne Heikkilä

引用次数: 0

Advanced avrami formula and its application to describing the isothermal crystallisation of polymers

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-04 DOI: 10.1016/j.tca.2025.179950

László Mihály Vas , Emese Slezák , Kolos Molnár , Ferenc Ronkay

{"title":"Advanced avrami formula and its application to describing the isothermal crystallisation of polymers","authors":"László Mihály Vas , Emese Slezák , Kolos Molnár , Ferenc Ronkay","doi":"10.1016/j.tca.2025.179950","DOIUrl":"10.1016/j.tca.2025.179950","url":null,"abstract":"<div><div>The classic Avrami formula has widely been used to describe and characterize the crystallisation process of polymers. We showed that the Avrami formula is not correct for the random nucleation. To eliminate this and some problems of fitting the Avrami formula with integer exponent revealed in the literature, we modified the Avrami equation and derived a new extended formula that can describe instantaneous and random (time-dependent) nucleation simultaneously. This formula may give information on the crystalline structure of both types of nuclei; moreover, it makes it possible to determine the crystalline fraction developed from the instantaneous nuclei. The latter enables us to estimate, for example, the effect of nucleating agents numerically on the crystallisation process and the ultimate crystallinity. The applicability of the new formula was validated by performing isothermal crystallisation tests on poly(ethylene-terephthalate) (PET), polypropylene (PP), low- and high-density polyethylene (LDPE and HDPE) samples at various temperatures, which resulted in a better fit characterized by the much smaller relative maximum absolute error (0.4–2.9 %) related to that for the Avrami equation (1.9–15.9 %).</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"746 ","pages":"Article 179950"},"PeriodicalIF":3.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350189","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}

引用次数: 0

Lyophilized globular proteins under rapid heating: High thermal stability and properties of the resulting material

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-01 DOI: 10.1016/j.tca.2024.179919

Timur Mukhametzyanov , Sanjarbek Nazimov , Christoph Schick

{"title":"Lyophilized globular proteins under rapid heating: High thermal stability and properties of the resulting material","authors":"Timur Mukhametzyanov , Sanjarbek Nazimov , Christoph Schick","doi":"10.1016/j.tca.2024.179919","DOIUrl":"10.1016/j.tca.2024.179919","url":null,"abstract":"<div><div>A notable feature of globular proteins is their relatively poor thermostability. Water, while being important in maintaining the native protein structure, participates in many thermal degradation processes either directly (hydrolysis, deamidation) or indirectly by enhancing the mobility of protein molecules. It has been long known that reducing hydration enhances the thermal stability of proteins. However, the temperature stability of essentially dry proteins is unexplored because the traditional means of heating cause the charring of proteins. Fast Scanning Calorimetry (FSC) is a technique that allows rapid heating and cooling of micrometer-size samples. It was previously used to determine the melting point of silk fibroin. Here we demonstrate that under rapid heating, the dried powders of globular proteins remain stable up to ca. 200 °C. Further heating produces a glass-like material without charring. The glass transition temperature of the produced material is above 200 °C. The results may be of potential interest for additive manufacturing of biocompatible products.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"744 ","pages":"Article 179919"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165562","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}

引用次数: 0

Facile preparation of functional decorated of phase change materials composites based on paraffin @ sodium alginate

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-01 DOI: 10.1016/j.tca.2024.179922

Xiangyun Kong , Jinge Lu , Mengkun Xu, Mengyuan Song, Keqing Li, Wenshuai Qiu, Jiali Zhang, Xi Chen, Yongxin Liu

{"title":"Facile preparation of functional decorated of phase change materials composites based on paraffin @ sodium alginate","authors":"Xiangyun Kong , Jinge Lu , Mengkun Xu, Mengyuan Song, Keqing Li, Wenshuai Qiu, Jiali Zhang, Xi Chen, Yongxin Liu","doi":"10.1016/j.tca.2024.179922","DOIUrl":"10.1016/j.tca.2024.179922","url":null,"abstract":"<div><div>A novel and simple one-step method was proposed for the preparation of multifunctional microencapsulated phase change materials to satisfy the requirements of different application scenarios. Here, with the help of the super reaction ability and coordination effect of metal ions Zn<sup>2+</sup>, the paraffin (PCM) was well encapsulated by the sodium alginate (SA) shell by the cross-linking between SA and Zn<sup>2+</sup>. At the same time, Na<sub>2</sub>S·9H<sub>2</sub>O and 2-MeIM were selected to realize the loading of ZnS quantum dots and ZiF-8 in the materials by their coordination with excess Zn<sup>2+</sup> in the system. The results of differential scanning calorimeter (DSC), Ultraviolet-visible-near-infrared (UV–vis-NIR), Photoluminescence and Brunauer–Emmett–Teller (BET) indicated that the obtained PCM@SA/ZnS and PCM@SA/ZiF-8 not only retained good heat resistance and heat storage properties, but also had new functions such as fluorescence and adsorption. This work would provide a new idea for the development of multi-functional composite materials.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"744 ","pages":"Article 179922"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165561","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}

引用次数: 0

Determination of polymorphic forms of hydroxy-2-naphthoic acid and the corresponding solubility in twelve mono-solvents

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-01 DOI: 10.1016/j.tca.2024.179921

Huanxin Li , Xin Ding , Bingling Yu , Feilong Sun , Bo Zhu , Kenan Sun

{"title":"Determination of polymorphic forms of hydroxy-2-naphthoic acid and the corresponding solubility in twelve mono-solvents","authors":"Huanxin Li , Xin Ding , Bingling Yu , Feilong Sun , Bo Zhu , Kenan Sun","doi":"10.1016/j.tca.2024.179921","DOIUrl":"10.1016/j.tca.2024.179921","url":null,"abstract":"<div><div>The polymorphs of 1‑hydroxy-2-naphthoic acid (HNA) were screened in twelve organic solvents. Five aprotic solvents – acetone, acetonitrile, methyl acetate, ethyl acetate, and n-propyl acetate – along with n-butanol crystalized HNA in Form II. Meanwhile, HNA in Form I was obtained from methanol, ethanol, n-propanol, isopropanol, 2-butanol, and isobutanol. Solubility data of the two polymorphs was determined with static method, and fitted with λh equation, van't Hoff equation, Apelblat model, NRTL, and Wilson model, with Apelblat the most accurate based on ARD and RMSD. The dissolving process was affected significantly by hydrogen bond propensity and cohesive energy density. Moreover, Hansen solubility parameters analyses indicate that the smaller <span><math><mrow><mstyle><mi>Δ</mi></mstyle><mover><mrow><msub><mi>δ</mi><mi>t</mi></msub></mrow><mo>‾</mo></mover></mrow></math></span>, the better solubility of HNA. Additionally, the intermolecular interactions imply that both the van der Waals interaction and hydrogen bonding interaction take the leading role in affecting the solubility. The thermodynamic parameters suggest that the dissolving process is spontaneous and entropy increasing.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"744 ","pages":"Article 179921"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165564","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}

引用次数: 0

New insights on thermal energy storage using nanoparticle enhanced tin

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2025-02-01 DOI: 10.1016/j.tca.2024.179918

Tagore M , Suganthi K S , Haariz J A , Rajan K S

引用次数: 0