Design and Thermal Profiling of Ethyl Carbazole-Based Poly(phenoxy-imine)s: Synthesis and Characterization

Design and Thermal Profiling of Ethyl Carbazole-Based Poly(phenoxy-imine)s: Synthesis and Characterization | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Design and Thermal Profiling of Ethyl Carbazole-Based Poly(phenoxy-imine)s: Synthesis and Characterization İsmet Kaya, Ahmet Hakan Yılmaz, Feyza Kolcu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6594080/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 21 Jul, 2025 Read the published version in Polymer Bulletin → Version 1 posted 9 You are reading this latest preprint version Abstract A series of Schiff base monomers were synthesized via the condensation of 3-amino-9-ethylcarbazole with various aldehydes, including 3-hydroxybenzaldehyde (3-HBA), 4-hydroxybenzaldehyde (4-HBA), 2-hydroxy-1-naphthaldehyde (2-HNA), and ortho-vanillin (OV). These monomers were subsequently polymerized through oxidative polycondensation using NaOCl as the oxidant to yield corresponding poly(phenoxy-imine)s, namely Poly(3ECIMP), Poly(4ECIMP), Poly(ECIMN), and Poly(ECIMMP). The chemical structures of the synthesized compounds were confirmed using FT-IR, UV-Vis, and both 1H and 13C NMR spectroscopy. Thermal characterization using TG-DTA and DSC demonstrated that the synthesized polymers possess excellent thermal stability, as evidenced by their glass transition temperatures between 145 and 161°C and char yields reaching up to 38.22% at 1000°C. Furthermore, limiting oxygen index (LOI) values exceeding 28% indicate that these materials exhibit self-extinguishing behavior. Photoluminescence studies conducted in DMF demonstrated intense fluorescence, particularly for Poly(ECIMN), which exhibited yellow-orange emission upon excitation at 502 nm due to the presence of naphthalene moieties that enhance π-electron delocalization. Optical and electrochemical band gap analyses indicated significantly reduced E g values for the polymers compared to their monomers, with Poly(ECIMN) showing the lowest band gap of 2.39 eV. Cyclic voltammetry results aligned with optical measurements, confirming improved charge transfer characteristics in the conjugated polymer backbone. Surface morphology assessed by FE-SEM revealed porous structures, suggesting applicability in gas adsorption or catalytic systems. Size exclusion chromatography (SEC) confirmed the formation of high molecular weight polymers with narrow polydispersity indices. Collectively, the unique combination of thermal durability, photophysical responsiveness, and structural robustness highlights the potential of these ethyl carbazole-based poly(phenoxy-imine)s in applications spanning optoelectronics, thermal protection, and fluorescence-based sensing. Oxidative Polycondensation Poly(phenoxy-imine)s Thermal Properties Photoluminescence Limiting Oxygen Index Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 21 Jul, 2025 Read the published version in Polymer Bulletin → Version 1 posted Editorial decision: Accepted 04 Jul, 2025 Reviews received at journal 23 Jun, 2025 Reviews received at journal 22 Jun, 2025 Reviewers agreed at journal 15 Jun, 2025 Reviewers agreed at journal 13 Jun, 2025 Reviewers invited by journal 13 Jun, 2025 Editor assigned by journal 05 May, 2025 Submission checks completed at journal 05 May, 2025 First submitted to journal 05 May, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6594080","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":471535209,"identity":"d9ca5a08-a79c-44b4-8b61-3388748ace50","order_by":0,"name":"İsmet Kaya","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIiWNgGAWjYBACCRCRACLYe8ACPHxEa+HhOcPAcABIsxGlBWy6RA5YCwNBLZLtZww/PPizTc5e8u3Bxx9z7GTYGJgfPrqBR4s0T46xRGLbbWMe6bxkg4PbkoEOYzM2zsGjRY4hx0AiseF2Yo90jpnEwW3MQC08bNJ4tfC/Mf6R8Od2fY/kGZCWesJapCWAhiew3U7gkeABaTlMWIvkjGdlFkC/GPacyTE2OLvtOA8bMwG/SJxP3nzzx5/b8uzAoHtQua3anp+9+eFjfFoYGDgM0ASY8SoHAfYHBJWMglEwCkbBCAcAadZFW556ytoAAAAASUVORK5CYII=","orcid":"","institution":"","correspondingAuthor":true,"prefix":"","firstName":"İsmet","middleName":"","lastName":"Kaya","suffix":""},{"id":471535210,"identity":"6b39a4a0-8a3f-4af7-8538-e28b1049edfe","order_by":1,"name":"Ahmet Hakan Yılmaz","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Ahmet","middleName":"Hakan","lastName":"Yılmaz","suffix":""},{"id":471535211,"identity":"8b8c716e-ee09-40d1-971b-e0d87ba3a9a1","order_by":2,"name":"Feyza Kolcu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Feyza","middleName":"","lastName":"Kolcu","suffix":""}],"badges":[],"createdAt":"2025-05-05 11:38:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6594080/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6594080/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00289-025-05932-y","type":"published","date":"2025-07-21T15:58:11+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":87756757,"identity":"22d2160a-77e7-46e1-be36-cb6e54b0307d","added_by":"auto","created_at":"2025-07-28 16:08:50","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1400555,"visible":true,"origin":"","legend":"","description":"","filename":"KayaFeyzaHakanPB2025.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6594080/v1_covered_70a451c7-5d26-4bc5-b20d-8727b1721811.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Design and Thermal Profiling of Ethyl Carbazole-Based Poly(phenoxy-imine)s: Synthesis and Characterization ","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"polymer-bulletin","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pobu","sideBox":"Learn more about [Polymer Bulletin](http://link.springer.com/journal/289)","snPcode":"289","submissionUrl":"https://submission.nature.com/new-submission/289/3","title":"Polymer Bulletin","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Oxidative Polycondensation, Poly(phenoxy-imine)s, Thermal Properties, Photoluminescence, Limiting Oxygen Index","lastPublishedDoi":"10.21203/rs.3.rs-6594080/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6594080/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eA series of Schiff base monomers were synthesized via the condensation of 3-amino-9-ethylcarbazole with various aldehydes, including 3-hydroxybenzaldehyde (3-HBA), 4-hydroxybenzaldehyde (4-HBA), 2-hydroxy-1-naphthaldehyde (2-HNA), and ortho-vanillin (OV). These monomers were subsequently polymerized through oxidative polycondensation using NaOCl as the oxidant to yield corresponding poly(phenoxy-imine)s, namely Poly(3ECIMP), Poly(4ECIMP), Poly(ECIMN), and Poly(ECIMMP). The chemical structures of the synthesized compounds were confirmed using FT-IR, UV-Vis, and both 1H and 13C NMR spectroscopy. Thermal characterization using TG-DTA and DSC demonstrated that the synthesized polymers possess excellent thermal stability, as evidenced by their glass transition temperatures between 145 and 161\u0026deg;C and char yields reaching up to 38.22% at 1000\u0026deg;C. Furthermore, limiting oxygen index (LOI) values exceeding 28% indicate that these materials exhibit self-extinguishing behavior. Photoluminescence studies conducted in DMF demonstrated intense fluorescence, particularly for Poly(ECIMN), which exhibited yellow-orange emission upon excitation at 502 nm due to the presence of naphthalene moieties that enhance π-electron delocalization. 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Collectively, the unique combination of thermal durability, photophysical responsiveness, and structural robustness highlights the potential of these ethyl carbazole-based poly(phenoxy-imine)s in applications spanning optoelectronics, thermal protection, and fluorescence-based sensing.\u003c/p\u003e","manuscriptTitle":"Design and Thermal Profiling of Ethyl Carbazole-Based Poly(phenoxy-imine)s: Synthesis and Characterization","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-17 16:01:23","doi":"10.21203/rs.3.rs-6594080/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accepted","date":"2025-07-04T08:44:46+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-23T19:59:57+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-22T12:44:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"80208185018243911122290560348240738713","date":"2025-06-15T16:41:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"108060691646489929510720011046225294542","date":"2025-06-13T10:55:03+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-06-13T08:46:48+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-05T15:22:11+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-05T15:05:49+00:00","index":"","fulltext":""},{"type":"submitted","content":"Polymer Bulletin","date":"2025-05-05T11:27:31+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"polymer-bulletin","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pobu","sideBox":"Learn more about [Polymer Bulletin](http://link.springer.com/journal/289)","snPcode":"289","submissionUrl":"https://submission.nature.com/new-submission/289/3","title":"Polymer Bulletin","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"c6329007-0bf3-4ed3-a028-578292870e1a","owner":[],"postedDate":"June 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-07-28T16:03:19+00:00","versionOfRecord":{"articleIdentity":"rs-6594080","link":"https://doi.org/10.1007/s00289-025-05932-y","journal":{"identity":"polymer-bulletin","isVorOnly":false,"title":"Polymer Bulletin"},"publishedOn":"2025-07-21 15:58:11","publishedOnDateReadable":"July 21st, 2025"},"versionCreatedAt":"2025-06-17 16:01:23","video":"","vorDoi":"10.1007/s00289-025-05932-y","vorDoiUrl":"https://doi.org/10.1007/s00289-025-05932-y","workflowStages":[]},"version":"v1","identity":"rs-6594080","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6594080","identity":"rs-6594080","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}