Journal of Analytical and Applied Pyrolysis最新文献

{"title":"Pyrolysis and oxidation characteristics and energy self-sustaining process design of retired wind turbine blades","authors":"Yili Zhang ,&nbsp;Zhaotianyi Zhang ,&nbsp;Wenjing Ma ,&nbsp;Pei Chen ,&nbsp;Bing Bai ,&nbsp;Linhui Li ,&nbsp;Yuan Lai ,&nbsp;Xuebin Wang","doi":"10.1016/j.jaap.2024.106872","DOIUrl":"10.1016/j.jaap.2024.106872","url":null,"abstract":"<div><div>Pyrolysis offers a straightforward method to extract valuable glass fiber from retired wind turbine blades, showing great potential for resource utilization. Experimental findings reveal that calorific value of pyrolysis gas increases with pyrolysis temperatures between 400 and 700 ℃. When the solid product obtained was oxidized at 500 ℃ for 40 minutes, clean glass fiber products can be obtained. Based on it, a new pyrolysis process for retired wind turbine blades and clean glass fiber recovery was designed using Aspen Plus software. By comparing the influence of pyrolysis temperatures, the stability and flexibility of the system were analyzed. The simulation results indicate that the pyrolysis temperature within the range of 400–700 ℃ can fully achieve energy self-sufficiency of the system, and excess heat can be stored by heating molten salts with high heat capacity. In practical applications, it is recommended to set the pyrolysis temperature and oxidation temperature at approximately 500 ℃, thereby further improving the economic efficiency of the system. This pyrolysis and recovery process can significantly improve its economic efficiency through energy self-sustaining system optimization, marking a significant contribution to the sustainable and economic management of retired wind turbine blade resources.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"185 ","pages":"Article 106872"},"PeriodicalIF":5.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701068","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}

{"title":"A comprehensively experimental and kinetic modeling investigation of tetrahydropyran pyrolysis and oxidation in a jet-stirred reactor","authors":"Hongyan Wang ,&nbsp;Xinyue Sun ,&nbsp;Yurou Zhou ,&nbsp;Xiaoyan Zhao ,&nbsp;Guozhu Liu ,&nbsp;Jingpei Cao","doi":"10.1016/j.jaap.2024.106871","DOIUrl":"10.1016/j.jaap.2024.106871","url":null,"abstract":"<div><div>Tetrahydropyran (THP), a kind of promising green cyclic-ether fuel derived from biomass, exhibits excellent resistance to autoignition characteristics and can be used as an alternative fuel or fuel additive to improve combustion efficiency as well as reduce harmful emissions. To further reveal insights into its high-temperature decomposition and low-and intermediate temperature oxidation behaviors closely related the deflagration to detonation in spark ignition engines, the comprehensive investigation of experiments and detailed kinetic modeling of THP were performed in the present work. The experiments at two equivalence ratios, i.e. ϕ = ∞ (pyrolysis) and ϕ = 1.0, were carried out in a jet-stirred quartz reactor at 1.0 atm and 733–1148 K. More than ten substances were identified and quantified by GC and GC/MS, including small hydrocarbons, oxygenated and stable products. A detailed kinetic model of THP pyrolysis and oxidation was developed by incorporating the O₂ additions of fuel radicals and updating the rate constants of key reactions, and validated and showed the slight an improvement for the speciation profiles newly reported in this work and those available in the previous literature over a wide experimental range of 450–1260 K and 1.0–10.0 atm. Rate of production analysis indicated that the H-abstractions by H attacking are the important pathways governing THP reactivity with a minor contribution from C-C and C-O dissociations of ring-opening reactions in high-temperature pyrolysis, whereas the H-abstractions triggered by OH and HO₂ largely control fuel consumption in low- and intermediate temperature oxidation. The formed three tetrahydropyranyls, especially α-tetrahydropyranyl, will proceed to decompose into acyclic C₅H₉O radicals via C-O and C-C β-scissions or C₅H₉OO₂-2 intermediates via O₂ addition in THP pyrolysis and oxidation, as the main source of small species. For the unique aromatics detected during the pyrolysis, the combination reactions of C2 + C4 unsaturated hydrocarbons predominantly determinate their generation. This work provides new experimental data and further analyses for understanding the pyrolysis and oxidation chemistry of THP and sheds light on directions for future practical application.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"185 ","pages":"Article 106871"},"PeriodicalIF":5.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700470","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}

{"title":"Methodologies for bio-oil characterization from biomass pyrolysis: A review focused on GC-MS","authors":"A.C.M. Vilas-Boas ,&nbsp;L.A.C. Tarelho ,&nbsp;J.M.O. Moura ,&nbsp;H.G.M.F. Gomes ,&nbsp;C.C. Marques ,&nbsp;D.T. Pio ,&nbsp;M.I.S. Nunes ,&nbsp;A.J.D. Silvestre","doi":"10.1016/j.jaap.2024.106850","DOIUrl":"10.1016/j.jaap.2024.106850","url":null,"abstract":"<div><div>Residual biomass pyrolysis offers a promising route for the production of bio-oil, which can be further processed into various green value-added fuels and chemicals. However, the complex composition of bio-oil requires thorough physicochemical characterization to optimize conversion processes and improve biomass-to-liquid technologies. This review provides a comprehensive appraisal of the influence of operating conditions, particularly biomass components, on the composition of bio-oil produced by pyrolysis, addresses physicochemical characterization methods, focusing on Gas Chromatography-Mass Spectrometry (GC-MS) for chemical analysis. Various analytical methods were reviewed, revealing differences in sample preparation, injection conditions, temperature programs, heating rates, chromatographic column dimensions, and stationary phases. The variety in methods difficult data comparison and highlights the need for standardized methodologies. While some approaches yield well-defined chromatograms with effective separation of bio-oil components, further assessments of repeatability and reproducibility are essential – both across laboratories using identical samples and within laboratories using varying samples. After compound identification, quantification using either GC-MS or GC-FID (GC with Flame Ionization Detection) with appropriate standards is recommended to enhance the reliability and validity of the results. Additionally, because GC-MS primarily identifies semi-volatile and volatile compounds, complementary techniques are necessary for a more comprehensive analysis. This review provides crucial insights into the existing methodologies and compiles a database of frequently identified compounds by GC-MS, aiming to support tool to the development of standardized methodologies for the accurate and comprehensive characterization of pyrolysis-derived bio-oils.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"185 ","pages":"Article 106850"},"PeriodicalIF":5.8,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701171","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}

{"title":"Studying the trimethylsilylation of alkylcatechols in Asian lacquers by analytical pyrolysis coupled with online micro-reaction sampler","authors":"Diego Tamburini ,&nbsp;Cecilia Campi ,&nbsp;Francesco Palmas ,&nbsp;Ilaria Bonaduce","doi":"10.1016/j.jaap.2024.106869","DOIUrl":"10.1016/j.jaap.2024.106869","url":null,"abstract":"<div><div>Asian lacquers are natural polymers obtained from the sap of trees of the Anacardiaceae family. Their main chemical components are long-chain alkylcatechols that form a complex polymeric network upon curing. Analytical pyrolysis is the most powerful tool to study these polymers from a chemical point of view. However, derivatisation of polar pyrolysis products, especially alkylcatechols, is needed to ensure their detection by gas chromatographic techniques. In this study, <em>in situ</em> trimethylsilylation using hexamethyldisilazane (HMDS) applied to the pyrolysis of urushi (<em>Toxicodendron vernicifluum</em>) and thitsi (<em>Gluta usitata</em>) lacquers was investigated to address the issue of partial derivatisation of alkylcatechols in flash pyrolysis conditions. By using an online micro-reaction sampler (MRS) coupled to pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), the derivatisation reaction was studied under controlled conditions. The reaction time between HMDS and lacquer pyrolysis products generated at 400 °C was investigated, proving that 12 s is sufficient for the complete trimethylsilylation of alkylcatechols. This information is crucial to understand the factors affecting <em>in situ</em> derivatisation, showing that slightly extending the contact time between the derivatising agent and the pyrolysis products is a relatively easy solution to partial derivatisation deriving from steric hindrance. This optimised procedure yields simpler chromatograms compared to flash pyrolysis and has high potential for the enhanced characterisation of these materials and the detection of lacquer molecular markers in samples containing complex mixtures of organic materials.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"185 ","pages":"Article 106869"},"PeriodicalIF":5.8,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701067","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}

{"title":"Development of hierarchical ZSM-11 for synthesis of light olefins from crude oil","authors":"Muhammad Waqas ,&nbsp;Ziyauddin S. Qureshi ,&nbsp;M. Abdullbari Siddiqui ,&nbsp;Abdullah Aitani ,&nbsp;Aaron C. Akah","doi":"10.1016/j.jaap.2024.106870","DOIUrl":"10.1016/j.jaap.2024.106870","url":null,"abstract":"<div><div>ZSM-11 is recognized as a shape-selective catalyst in various industrial processes; however, the significance of hierarchical ZSM-11 in the direct conversion of crude oil to light olefins remains unexplored. Herein, we report a template-directed hydrothermal method to synthesize hierarchical ZSM-11 zeolite with varying secondary mesopore sizes, acidities, and morphologies. The synthesis strategy controlled the development of uniform nanorods or accumulating nanosized zeolites with SiO₂/Al₂O₃ molar ratios of 30, 35, and 70. The developed two-dimensional 10-membered ring straight channels ZSM-11 catalyst were employed firstly for the steam catalytic cracking of light crude oil to produce light olefins (C₂-C₄). Amongst the various developed catalysts, ZSM-11(35), a hierarchical zeolite with SiO₂/Al₂O₃ molar ratio of 35, outperformed in terms of crude oil cracking conversion (∼66.5 %) and selectivity to C₂-C₄ light olefins (44.1 %). In comparison to diffusion over sinusoidal channels in ZSM-5, ZSM-11 zeolite with tortuous and straight channels facilitated rapid mass transport at low coke deposition.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"185 ","pages":"Article 106870"},"PeriodicalIF":5.8,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701066","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}

{"title":"Recovery of value-added compounds through fast pyrolysis of apple pomace hydrochar","authors":"Madeline Karod ,&nbsp;Kellene A. Orton ,&nbsp;Yaseen Elkasabi ,&nbsp;Charles A. Mullen ,&nbsp;Anne E. Harman-Ware ,&nbsp;Kristiina Iisa ,&nbsp;Jillian L. Goldfarb","doi":"10.1016/j.jaap.2024.106868","DOIUrl":"10.1016/j.jaap.2024.106868","url":null,"abstract":"<div><div>The environmental challenges associated with food production can be addressed via the thermochemical upcycling of agro-industrial biomass. Two such methods, hydrothermal carbonization (HTC) and pyrolysis, can be coupled to first reduce the water content of wet biomass wastes by producing a hydrochar (HC) via HTC and then a bio-oil via pyrolysis of the HC. However, HTC of biomass results in the formation of secondary char (SC), an amorphous tar-like mixture resulting from organic compounds released into the aqueous phase that adsorb, recondense and polymerize on the parent biomass. This study investigated how HTC temperature impacts the formation of SC from apple pomace and the SC’s subsequent impact on fast pyrolysis products. HCs were produced at temperatures of 175°C, 200°C, and 250°C. Lower HTC temperatures favor the formation of biorefinery platform chemicals such as 5-hydroxymethylfurfural and levulinic acid, while higher temperatures result in increased lignin degradation products (i.e., phenolics). HCs were subjected to fast pyrolysis before and after SC extraction in two analytical pyrolysis instruments. Fast pyrolysis of HC produced compounds similar to those found in SC, but with variations in CO and CO₂ emissions. The combination of SC extraction and fast pyrolysis demonstrates promise for recovering value-added compounds from agro-industrial waste biomass while retaining a solid char for fuel and carbon management.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"185 ","pages":"Article 106868"},"PeriodicalIF":5.8,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701079","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}

{"title":"Catalytic vapor phase upgrading of sawdust pyrolysis using metal oxide catalysts: The support effect","authors":"Ranjita Singh ,&nbsp;Vaibhav Anand ,&nbsp;Nandana Chakinala ,&nbsp;Kaustubha Mohanty ,&nbsp;Anand G. Chakinala","doi":"10.1016/j.jaap.2024.106864","DOIUrl":"10.1016/j.jaap.2024.106864","url":null,"abstract":"<div><div>Biocrude derived from biomass is unstable and has limited applications and vapor-phase upgrading of biomass pyrolysis over a catalyst can enhance bio-oil quality and yield, yet catalyst deactivation due to coke formation remains a major challenge. This study explores the effects of different magnesium oxide (MgO) catalysts supported on ZSM-5, Al₂O₃, ZrO₂, TiO₂ on the pyrolysis product yield, composition, and the extent of coke formation. Studies were conducted in a fixed-bed reactor at 550 °C at two different catalyst to biomass loadings (C/B) of 1:6, and 1:1. Non catalytic pyrolysis of sawdust resulted in the biocrude, gas, and char yields of ∼32 wt%, ∼29 wt%, and ∼39 wt% respectively. At a low C/B ratio, pyrolysis product yields were approximately comparable to those under non-catalytic conditions. However, at a high C/B ratio, biocrude yield decreased significantly with increase in gas yield, while char yield showed only minor changes. Using ZSM-5 and Al₂O₃ supported catalysts, low C/B ratios significantly increased phenolic content in the biocrude (∼58%). In contrast, higher C/B ratios enhanced the hydrocarbons (∼10%) and aromatics (∼32%) content, reducing phenolics and thereby lowering the biocrude's overall oxygen content, enhancing its stability. TiO₂ and ZrO₂ supports produced higher proportions of lower carbon chain length compounds, though with reduced hydrocarbon content compared to ZSM-5. ZSM-5 supported catalysts yield a high proportion of aromatic compounds, attributed to the synergy between the acidic sites of ZSM-5 and the basic sites of MgO that favored conversion of phenolics to aromatics through dehydroxylation and demethoxylation. Overall, this study highlights the influence of different catalyst supports in catalytic vapor phase upgrading of sawdust derived biocrude to selectively optimize bio-oil composition, increasing fuel or chemical potential while addressing coke formation.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"185 ","pages":"Article 106864"},"PeriodicalIF":5.8,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700471","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}

{"title":"Unravelling the multifarious role of wood vinegar made from waste biomass in plant growth promotion, biotic stress tolerance, and sustainable agriculture","authors":"Sumit Kumar ,&nbsp;Mehjebin Rahman ,&nbsp;Ali Chenari Bouket ,&nbsp;Reza Ahadi ,&nbsp;Mukesh Meena ,&nbsp;Ingudam Bhupenchandra ,&nbsp;Udai B. Singh ,&nbsp;R. Arutselvan ,&nbsp;Ravindra Kumar ,&nbsp;Satyendra Pratap Singh ,&nbsp;Abhijeet S. Kashyap ,&nbsp;Ruchi Tripathi ,&nbsp;Sachin Gupta ,&nbsp;Pranab Dutta ,&nbsp;Harish ,&nbsp;Ramesh Singh ,&nbsp;Prashant Swapnil","doi":"10.1016/j.jaap.2024.106851","DOIUrl":"10.1016/j.jaap.2024.106851","url":null,"abstract":"<div><div>The population of the world has increased intensively, and sustainable agriculture practices are important in achieving the zero-hunger goal. The agriculture sector is constantly facing serious problems caused by climate change and the occurrence of pesticide-resistant causal agents. In this context, one of the most crucial eco-friendly approaches, e.g., using plant-derived bioproducts, is gaining more attraction because they have multifarious potential to overcome challenges. Wood vinegar (WV) or pyroligneous acid (PA) is a liquid biomaterial that is produced by the thermo-pyrolysis process of woody biomass and it was defined as a reddish-brown aqueous liquid that contains methanol, acetic acid, tars, and wood oils by the distillation process of woods. PA production and their application in agricultural fields, have attracted more attention recently because they may work as good bio-stimulants, biopesticides, and biofertilizers. Therefore, it may open a novel, promising window for agriculture and food production. PA has a significant role in elevating plant agronomic activities such as seed germination and vigor index, plant growth, nutritional value, and crop yields. This review aims to discuss in detail the following items: 1) The composition of wood vinegar and its production system; 2) Seed priming with the PA process; 3) Investigation of the role of PA in plant growth promotion activities, biocontrol potential, and its applications for alleviating biotic stresses; 4) Describe the molecular mode of action of PA in suppressing plant diseases causal agents and promoting plant immunity through a well-illustrated diagram; 5) Evaluation of PA role in soil physicochemical, biological, and enzymatic activities and its impact on improving compost quality and curtailing emissions of green house gasses; 6) PA different advantages and limitations, as well as future perspectives for its usage and development.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"185 ","pages":"Article 106851"},"PeriodicalIF":5.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701174","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}

{"title":"Towards enhanced understanding of the synergistic effects between potassium and calcium in biomass catalyzed pyrolysis","authors":"Zhiheng Ye ,&nbsp;Si Li ,&nbsp;Zhiyan Pan ,&nbsp;Junliang Wang ,&nbsp;Zhong-Ting Hu ,&nbsp;Chunbao Charles Xu ,&nbsp;Mian Hu","doi":"10.1016/j.jaap.2024.106848","DOIUrl":"10.1016/j.jaap.2024.106848","url":null,"abstract":"<div><div>In this study, the influences of different parameters on the products of K-Ca synergistically catalyzed biomass pyrolysis and the possible chemical reactions during the process were investigated. Results indicated that, according to the standard Gibbs energy calculations, Ca(OH)₂ was more likely to react with carboxyl groups (precursors of CO₂) in biomass than KOH at low temperature (&lt; 600 °C), effectively preventing the generation of CO₂. Increasing the amount of Ca(OH)₂ significantly enhanced this interaction, resulting in gradually decrease of CO₂ and CO, and remarkably promoted the generation of H₂. With a considerable decrease in the O-containing species, the hydrocarbons and phenols (phenol accounting for 49 %) became the main species in organic liquid products. For solid products, KOH can react and remove most of the oxygen-containing functional groups, while Ca(OH)₂ can fixed O-C<img>O groups, resulting in a large amount of O-C<img>O groups remaining. Additionally, bimetallic carbonate K₂Ca(CO₃)₂ was formed at Ca(OH)₂/KOH/soybean straw ratios below 0.25:1:2, whereas K₂Ca₂(CO₃)₃ was generated at higher ratios exceeding 0.25:1:2. At higher temperatures (&gt; 600 °C), the O-C<img>O groups transformed into more stable C<img>O groups, and K₂Ca₂(CO₃)₃ decomposed into K₂Ca(CO₃)₂, which increased the content of CO via hydrogenation. As analyzed above, the mechanism of K-Ca synergistically catalyzed biomass pyrolysis was elucidated.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"184 ","pages":"Article 106848"},"PeriodicalIF":5.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661304","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}

{"title":"Study on the aging behavior and mechanism of nitrile rubber composites in combined radiation-thermal environments","authors":"Ruiyang Dou,&nbsp;Yiqian Zhang,&nbsp;Zhendong Huang,&nbsp;Qiang Liu,&nbsp;Wei Huang,&nbsp;Xianfu Meng,&nbsp;Hongbing Chen","doi":"10.1016/j.jaap.2024.106865","DOIUrl":"10.1016/j.jaap.2024.106865","url":null,"abstract":"<div><div>This contribution investigates the aging property changes and mechanism of nitrile rubber (NBR) under the combined radiation-thermal environments in the N₂ atmosphere. Aging resulted in a decrease in elongation at break from 309.01 % to 64.74 %, an increase in modulus of elasticity from 3.84 MPa to 9.09 MPa, and a slight increase in thermal stability. The crosslink density increases and the mass loss of the sample is reduced, while the chemical structure of the sample surface is almost intact. By gas-phase infrared spectroscopy, the irradiation aging-induced gases from NBR were also analyzed, including CO₂, CO, and alkanes (CH₄, C₂H₆, C₃H₈). This indicates that chain scission and pendant group removal also take place, whereas chain breaking primarily occurs at the macromolecular chain end. The above degradation reactions and the decomposed additives account for the generated trace amount of small molecule gas products. These findings suggest that the primary aging mechanisms of NBR are the cross-linking of macromolecular chains and additive loss. Furthermore, radiation and thermal have a synergistic effect on NBR aging, and this effect has a threshold temperature that is clearly between 50 °C and 70 °C. The synergistic effect of additive cleavage is only apparent at temperatures above 65 °C under radiation-thermal conditions.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"184 ","pages":"Article 106865"},"PeriodicalIF":5.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661279","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}