Humidity-Robust Semi-Aromatic Polyimides with Cyclohexyl-Substituted Double-Decker-Shaped Silsesquioxane Exhibiting Ultra-Low Dielectric Losses at 10-20 GHz

Humidity-Robust Semi-Aromatic Polyimides with Cyclohexyl-Substituted Double-Decker-Shaped Silsesquioxane Exhibiting Ultra-Low Dielectric Losses at 10-20 GHz | 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 Article Humidity-Robust Semi-Aromatic Polyimides with Cyclohexyl-Substituted Double-Decker-Shaped Silsesquioxane Exhibiting Ultra-Low Dielectric Losses at 10-20 GHz Teruaki Hayakawa, Natsuko Sashi, Erina Yoshida, Hayato Maeda, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8636989/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Emerging high-frequency electronics require polymer dielectrics that combine a low dielectric constant ( D k ) with an ultra-low dissipation factor ( D f ) under realistic humidity. Here, we report semi-aromatic polyimides (PIs) incorporating cyclohexyl-substituted double-decker-shaped silsesquioxane (C-DDSQ) units that simultaneously suppress electronic and dipolar polarizations while limiting water uptake. The best formulation shows D k = 2.57 and D f = 0.0019 at 10 GHz under 30% RH, and maintains minimal changes up to 60% RH ( ΔD k ≈ 0.02, ΔD f ≈ 0.0003). Wide-angle X-ray diffraction confirms the retention of the cage-like silsesquioxane motif, and thermogravimetric analysis shows T d−10 ≥ 470°C, indicating robust thermal endurance. Correlating D k with in-plane refractive index ( n TE ) reveals that the lowered n and the rigid, hydrophobic architecture of C-DDSQ account for the low losses at 10–20 GHz. These results position C-DDSQ-incorporating semi-aromatic PIs as promising interlayer dielectrics that deliver ultra-low loss, humidity stability, and high thermal tolerance without resorting to porosity or heavy fluorination. Physical sciences/Chemistry/Materials chemistry/Soft materials/Polymers Physical sciences/Materials science/Nanoscale materials/Electronic properties and materials Full Text Additional Declarations There is NO Competing Interest. Supplementary Files ncsupplementaryInformationTH.pdf Supplementary information for: Humidity-robust semi-aromatic polyimides with cyclohexyl-substituted double-decker-shaped silsesquioxane for ultra-low dielectric loss at 10-20 GHz Cite Share Download PDF Status: Under Review 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-8636989","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":594106342,"identity":"be8ae15c-f807-427c-89a9-571f245db00d","order_by":0,"name":"Teruaki Hayakawa","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIiWNgGAWjYBACAyBmbAAS/HAuGPAQoUWyAUQbwBQTo8XgAITGpxgCzNnPGH6cUXNY3vja4ecPGArq5O0ZmB9+YJC5g1OLZU+OseSGY4cNt91OMwQ67LBhDwObsQQDzzPcDjuQYyD5gO0247bbOSC/HEgAOswM6LzDuLWcf2P888G/2/abZ4O11AG1sH/Dr+VGjpnkxrbbiRukwVqYgVp4CNhy41mZ5cy+/8kzgH6ZkQDyy2GeYokEfH45n7z5Zs+3NNv+2ckPPnz4UyfP3t6+8cPHHtwhxsDAYYBgJ4AIZiBO7DmARwv7A2yiP/BpGQWjYBSMghEGAEaqVxSyOySLAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-1704-5841","institution":"Institute of Science Tokyo","correspondingAuthor":true,"prefix":"","firstName":"Teruaki","middleName":"","lastName":"Hayakawa","suffix":""},{"id":594106343,"identity":"c60436bc-ac93-458e-8da5-25737c2d7b07","order_by":1,"name":"Natsuko Sashi","email":"","orcid":"","institution":"Institute of Science Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Natsuko","middleName":"","lastName":"Sashi","suffix":""},{"id":594106344,"identity":"4b85daff-2768-4206-941b-7f13d1076297","order_by":2,"name":"Erina Yoshida","email":"","orcid":"","institution":"Institute of Science Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Erina","middleName":"","lastName":"Yoshida","suffix":""},{"id":594106345,"identity":"3762118c-90b8-4178-9571-23f8a211d838","order_by":3,"name":"Hayato Maeda","email":"","orcid":"","institution":"Institute of Science Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Hayato","middleName":"","lastName":"Maeda","suffix":""},{"id":594106346,"identity":"99525f9f-e595-4748-b92d-2e793e4d3721","order_by":4,"name":"Riku Takahashi","email":"","orcid":"","institution":"Institute of Science Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Riku","middleName":"","lastName":"Takahashi","suffix":""},{"id":594106347,"identity":"60b797bb-2051-4c68-9591-ecff8963d32a","order_by":5,"name":"Kan Hatakeyama-Sato","email":"","orcid":"","institution":"Institute of Science Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Kan","middleName":"","lastName":"Hatakeyama-Sato","suffix":""},{"id":594106348,"identity":"511ed5ff-f516-4174-a63a-07771b65e8db","order_by":6,"name":"Yuta Nabae","email":"","orcid":"","institution":"Institute of Science Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Yuta","middleName":"","lastName":"Nabae","suffix":""},{"id":594106349,"identity":"6bf9c2c1-a9e5-4ebe-8a8d-018acb33decd","order_by":7,"name":"Ririka Sawada","email":"","orcid":"","institution":"Institute of Science Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Ririka","middleName":"","lastName":"Sawada","suffix":""},{"id":594106350,"identity":"8e337863-26f5-4b96-b420-47d2ce00602d","order_by":8,"name":"Shinji Ando","email":"","orcid":"","institution":"Institute of Science Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Shinji","middleName":"","lastName":"Ando","suffix":""}],"badges":[],"createdAt":"2026-01-19 08:42:50","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8636989/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8636989/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103505963,"identity":"8a29f86a-6969-4e03-be17-7706430a63f2","added_by":"auto","created_at":"2026-02-26 13:33:39","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3755010,"visible":true,"origin":"","legend":"Article File","description":"","filename":"ncpapersashidraftver20TH.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8636989/v1_covered_04465a54-45c0-45cf-a5a8-d15e57526323.pdf"},{"id":103342690,"identity":"e5839437-6e21-451b-bfe2-50ced6b2e2b8","added_by":"auto","created_at":"2026-02-24 15:48:03","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":21798139,"visible":true,"origin":"","legend":"Supplementary information for: Humidity-robust semi-aromatic polyimides with cyclohexyl-substituted double-decker-shaped silsesquioxane for ultra-low dielectric loss at 10-20 GHz","description":"","filename":"ncsupplementaryInformationTH.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8636989/v1/384a9f31f3eef0229e9752b7.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Humidity-Robust Semi-Aromatic Polyimides with Cyclohexyl-Substituted Double-Decker-Shaped Silsesquioxane Exhibiting Ultra-Low Dielectric Losses at 10-20 GHz","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":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8636989/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8636989/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eEmerging high-frequency electronics require polymer dielectrics that combine a low dielectric constant (\u003cem\u003eD\u003c/em\u003e\u003csub\u003ek\u003c/sub\u003e) with an ultra-low dissipation factor (\u003cem\u003eD\u003c/em\u003e\u003csub\u003ef\u003c/sub\u003e) under realistic humidity. Here, we report semi-aromatic polyimides (PIs) incorporating cyclohexyl-substituted double-decker-shaped silsesquioxane (C-DDSQ) units that simultaneously suppress electronic and dipolar polarizations while limiting water uptake. The best formulation shows \u003cem\u003eD\u003c/em\u003e\u003csub\u003ek\u003c/sub\u003e = 2.57 and \u003cem\u003eD\u003c/em\u003e\u003csub\u003ef\u003c/sub\u003e = 0.0019 at 10 GHz under 30% RH, and maintains minimal changes up to 60% RH (\u003cem\u003eΔD\u003c/em\u003e\u003csub\u003ek\u003c/sub\u003e \u0026asymp; 0.02, \u003cem\u003eΔD\u003c/em\u003e\u003csub\u003ef\u003c/sub\u003e \u0026asymp; 0.0003). Wide-angle X-ray diffraction confirms the retention of the cage-like silsesquioxane motif, and thermogravimetric analysis shows \u003cem\u003eT\u003c/em\u003e\u003csub\u003ed\u0026minus;10\u003c/sub\u003e \u0026ge; 470\u0026deg;C, indicating robust thermal endurance. Correlating \u003cem\u003eD\u003c/em\u003e\u003csub\u003ek\u003c/sub\u003e with in-plane refractive index (\u003cem\u003en\u003c/em\u003e\u003csub\u003eTE\u003c/sub\u003e) reveals that the lowered \u003cem\u003en\u003c/em\u003e and the rigid, hydrophobic architecture of C-DDSQ account for the low losses at 10\u0026ndash;20 GHz. These results position C-DDSQ-incorporating semi-aromatic PIs as promising interlayer dielectrics that deliver ultra-low loss, humidity stability, and high thermal tolerance without resorting to porosity or heavy fluorination.\u003c/p\u003e","manuscriptTitle":"Humidity-Robust Semi-Aromatic Polyimides with Cyclohexyl-Substituted Double-Decker-Shaped Silsesquioxane Exhibiting Ultra-Low Dielectric Losses at 10-20 GHz","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-24 15:47:58","doi":"10.21203/rs.3.rs-8636989/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"communications-materials","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"commsmat","sideBox":"Learn more about [Communications Materials](https://www.nature.com/commsmat/)","snPcode":"","submissionUrl":"","title":"Communications Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Communications Series","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"8fd29dff-a5e9-4c08-bfb9-b5411cb0b2fd","owner":[],"postedDate":"February 24th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":63223830,"name":"Physical sciences/Chemistry/Materials chemistry/Soft materials/Polymers"},{"id":63223831,"name":"Physical sciences/Materials science/Nanoscale materials/Electronic properties and materials"}],"tags":[],"updatedAt":"2026-05-13T07:29:16+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-24 15:47:58","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8636989","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8636989","identity":"rs-8636989","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}