Unravelling the Time-dependent Viscoelasticity of Polymers: The Dual Role of Temperature and Nanoindentation Depth

Unravelling the Time-dependent Viscoelasticity of Polymers: The Dual Role of Temperature and Nanoindentation Depth | 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 Unravelling the Time-dependent Viscoelasticity of Polymers: The Dual Role of Temperature and Nanoindentation Depth Desigan R, Payel Bandyopadhyay This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6937738/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Understanding the nanoscale viscoelastic response of polymers is essential for applications requiring long-term dimensional stability. This study investigates the viscoelastic creep behaviour of PMMA and epoxy using nanoindentation at two distinct depths (300 nm and 700 nm) across different temperatures (30°C − 55°C). A load-controlled nanoindentation test, combined with holding at maximum load, is used to analyse the time dependent deformation. The mechanical properties, such as elastic modulus and hardness, show significant depth and temperature dependent softening, with epoxy demonstrating superior mechanical strength below its glass transition temperature (T g − 45°C), while PMMA exhibits greater stability above this threshold. Burgers model analysis of creep displacement reveals fundamental differences in molecular mechanisms through the key parameters like instantaneous creep deformation (h 0 ), the time-dependent creep deformation (h 1 ), retardation time (τ 1 ) and viscosity coefficient (η 0 ). Epoxy’s viscosity exceeds that of PMMA at low temperatures but drops significantly near its T g , reflecting enhanced viscous flow due to crosslink network mobility. In contrast, PMMA’s amorphous structure maintains more consistent viscoelastic parameters. At greater depths, viscosity decreases for both the materials. These findings highlight the influence of molecular architecture on governing time dependent deformation, offering actionable insights for optimizing polymer performance in structural, aerospace, and biomedical applications. Nanoindentation Creep Viscoelastic properties Burgers model Glass transition temperature Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-6937738","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":485434610,"identity":"af682f7a-f784-49d6-9561-98fde4f19cab","order_by":0,"name":"Desigan R","email":"","orcid":"","institution":"SRM Institute of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Desigan","middleName":"","lastName":"R","suffix":""},{"id":485434611,"identity":"db5b534b-be39-4783-9c4e-8aeea7c8a74e","order_by":1,"name":"Payel Bandyopadhyay","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5ElEQVRIie2OoQrCUBSGzzDMZr0w9g5XBg5BtlfxMNCyZjEOhGsRoyj4ELMtHliwDK3CykQwGSYWm15cstxpE7xf+DkH/g9+AI3mVzlGPZlGBFVWhxqMBlWZvlDS6iD4oO+aWbvAZO+7i3RyK6Fnx9QQhUrpzkKHY5bjOkfBCAZOTMaUqxROYYehyPvMQiGHpSgVwZTK/uLeUex8qUxKgscHyiHsAAoylhZGchjVK93lecQwC1AqgmU8cFZpjeK2gk15TTw5bHgqx2PPnm+nZ/UwaPK3F6Ch6r86ZlFT0Wg0mr/nCZ7tUh8wm3mQAAAAAElFTkSuQmCC","orcid":"","institution":"SRM Institute of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Payel","middleName":"","lastName":"Bandyopadhyay","suffix":""}],"badges":[],"createdAt":"2025-06-20 09:53:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6937738/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6937738/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":89322239,"identity":"bd423256-3b13-4238-bf4f-283e519f6409","added_by":"auto","created_at":"2025-08-18 19:01:29","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":999732,"visible":true,"origin":"","legend":"","description":"","filename":"ManuscriptFinalversion.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6937738/v1_covered_4b1f7e5d-ee84-4b10-9b50-c6b6c5d68a86.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Unravelling the Time-dependent Viscoelasticity of Polymers: The Dual Role of Temperature and Nanoindentation Depth","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Nanoindentation, Creep, Viscoelastic properties, Burgers model, Glass transition temperature","lastPublishedDoi":"10.21203/rs.3.rs-6937738/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6937738/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eUnderstanding the nanoscale viscoelastic response of polymers is essential for applications requiring long-term dimensional stability. This study investigates the viscoelastic creep behaviour of PMMA and epoxy using nanoindentation at two distinct depths (300 nm and 700 nm) across different temperatures (30\u0026deg;C \u0026minus;\u0026thinsp;55\u0026deg;C). A load-controlled nanoindentation test, combined with holding at maximum load, is used to analyse the time dependent deformation. The mechanical properties, such as elastic modulus and hardness, show significant depth and temperature dependent softening, with epoxy demonstrating superior mechanical strength below its glass transition temperature (T\u003csub\u003eg\u003c/sub\u003e \u0026minus;\u0026thinsp;45\u0026deg;C), while PMMA exhibits greater stability above this threshold. Burgers model analysis of creep displacement reveals fundamental differences in molecular mechanisms through the key parameters like instantaneous creep deformation (h\u003csub\u003e0\u003c/sub\u003e), the time-dependent creep deformation (h\u003csub\u003e1\u003c/sub\u003e), retardation time (τ\u003csub\u003e1\u003c/sub\u003e) and viscosity coefficient (η\u003csub\u003e0\u003c/sub\u003e). Epoxy\u0026rsquo;s viscosity exceeds that of PMMA at low temperatures but drops significantly near its T\u003csub\u003eg\u003c/sub\u003e, reflecting enhanced viscous flow due to crosslink network mobility. In contrast, PMMA\u0026rsquo;s amorphous structure maintains more consistent viscoelastic parameters. At greater depths, viscosity decreases for both the materials. These findings highlight the influence of molecular architecture on governing time dependent deformation, offering actionable insights for optimizing polymer performance in structural, aerospace, and biomedical applications.\u003c/p\u003e","manuscriptTitle":"Unravelling the Time-dependent Viscoelasticity of Polymers: The Dual Role of Temperature and Nanoindentation Depth","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-17 12:49:48","doi":"10.21203/rs.3.rs-6937738/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"95c14f40-0b82-4d9c-879e-919f7efd6ad2","owner":[],"postedDate":"July 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-08-18T18:53:14+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-17 12:49:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6937738","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6937738","identity":"rs-6937738","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}