Interlaminar fracture toughness of carbon fiber/epoxy–polyimine laminates with dynamic imine bonds

Interlaminar fracture toughness of carbon fiber/epoxy–polyimine laminates with dynamic imine bonds | 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 Interlaminar fracture toughness of carbon fiber/epoxy–polyimine laminates with dynamic imine bonds Nuoyi Wu, Si Zhang, Chuanbo An, Zhiying Sun, Xu Li, Fuying Zhao, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8441342/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 14 You are reading this latest preprint version Abstract Interlaminar delamination limits the damage tolerance of carbon-fiber laminates and remains challenging to quantify and mitigate using conventional thermoset matrices. Here, the Mode I and Mode II interlaminar fracture behavior of carbon-fiber/epoxy-polyimine laminates containing dynamic imine bonds was investigated using double-cantilever beam and end-notched flexure tests, with cohesive-zone simulations employed to assist interpretation. The polyimine used in this study is chemically distinct from polyimide, as it is based on reversible imine (C = N) bonds rather than permanent imide linkages. The laminates exhibit interlaminar fracture toughness values of 2.39 kJ/m²in Mode I and 6.03 kJ/m²in Mode II. The simulations show good agreement with the measured load-displacement responses and support the interpretation that the dynamic interface delays delamination growth. As an additional demonstration, partial property recovery is observed after hot-press treatment, indicating potential for maintainable laminate structures. Overall, the results provide experimental evidence and supporting modeling for improving delamination resistance in epoxy-based carbon-fiber laminates via dynamic imine bonding. Carbon fiber reinforced epoxy-polyimine composites Dynamic imine bond modification Fracture toughness Hot-press repairability Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 05 May, 2026 Reviewers agreed at journal 03 May, 2026 Reviews received at journal 02 May, 2026 Reviewers agreed at journal 01 May, 2026 Reviews received at journal 29 Jan, 2026 Reviews received at journal 23 Jan, 2026 Reviews received at journal 19 Jan, 2026 Reviewers agreed at journal 15 Jan, 2026 Reviewers agreed at journal 15 Jan, 2026 Reviewers agreed at journal 13 Jan, 2026 Reviewers invited by journal 13 Jan, 2026 Editor assigned by journal 26 Dec, 2025 Submission checks completed at journal 26 Dec, 2025 First submitted to journal 24 Dec, 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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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-8441342","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":573792244,"identity":"383b0168-2676-4abe-9d15-a57a73a58f9c","order_by":0,"name":"Nuoyi Wu","email":"","orcid":"","institution":"Jiangsu University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Nuoyi","middleName":"","lastName":"Wu","suffix":""},{"id":573792246,"identity":"e269c1d4-1ca0-4d07-9ecb-b9ed5682eb5b","order_by":1,"name":"Si 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bonds","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"applied-composite-materials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"acma","sideBox":"Learn more about [Applied Composite Materials](http://link.springer.com/journal/10443)","snPcode":"10443","submissionUrl":"https://submission.nature.com/new-submission/10443/3","title":"Applied Composite Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Carbon fiber reinforced epoxy-polyimine composites, Dynamic imine bond modification, Fracture toughness, Hot-press repairability","lastPublishedDoi":"10.21203/rs.3.rs-8441342/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8441342/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eInterlaminar delamination limits the damage tolerance of carbon-fiber laminates and remains challenging to quantify and mitigate using conventional thermoset matrices. Here, the Mode I and Mode II interlaminar fracture behavior of carbon-fiber/epoxy-polyimine laminates containing dynamic imine bonds was investigated using double-cantilever beam and end-notched flexure tests, with cohesive-zone simulations employed to assist interpretation. The polyimine used in this study is chemically distinct from polyimide, as it is based on reversible imine (C\u0026thinsp;=\u0026thinsp;N) bonds rather than permanent imide linkages. The laminates exhibit interlaminar fracture toughness values of 2.39 kJ/m\u0026sup2;in Mode I and 6.03 kJ/m\u0026sup2;in Mode II. The simulations show good agreement with the measured load-displacement responses and support the interpretation that the dynamic interface delays delamination growth. As an additional demonstration, partial property recovery is observed after hot-press treatment, indicating potential for maintainable laminate structures. Overall, the results provide experimental evidence and supporting modeling for improving delamination resistance in epoxy-based carbon-fiber laminates via dynamic imine bonding.\u003c/p\u003e","manuscriptTitle":"Interlaminar fracture toughness of carbon fiber/epoxy–polyimine laminates with dynamic imine bonds","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-14 17:31:00","doi":"10.21203/rs.3.rs-8441342/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-05-05T17:49:10+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"245332856786675422508830821090231466337","date":"2026-05-03T13:52:28+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-02T08:50:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"146063571403132493401638578337390142322","date":"2026-05-01T09:08:36+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-29T07:47:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-23T14:57:04+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-19T07:23:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"206621278011039742084227720439189453587","date":"2026-01-15T14:08:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"256974201650529211583424286387639109146","date":"2026-01-15T12:29:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"161854591618431633847929860899361124841","date":"2026-01-13T09:09:31+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-13T08:49:36+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-27T00:17:06+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-12-27T00:16:38+00:00","index":"","fulltext":""},{"type":"submitted","content":"Applied Composite Materials","date":"2025-12-24T09:20:36+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"applied-composite-materials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"acma","sideBox":"Learn more about [Applied Composite Materials](http://link.springer.com/journal/10443)","snPcode":"10443","submissionUrl":"https://submission.nature.com/new-submission/10443/3","title":"Applied Composite Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"4a597c12-6729-47e5-8f58-197237d88023","owner":[],"postedDate":"January 14th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-05-05T17:49:10+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"245332856786675422508830821090231466337","date":"2026-05-03T13:52:28+00:00","index":67,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-02T08:50:23+00:00","index":64,"fulltext":""},{"type":"reviewerAgreed","content":"146063571403132493401638578337390142322","date":"2026-05-01T09:08:36+00:00","index":62,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-05-05T17:54:41+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-14 17:31:00","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8441342","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8441342","identity":"rs-8441342","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}