{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T20:20:26Z","timestamp":1784838026946,"version":"3.55.0"},"reference-count":58,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2024,9,18]],"date-time":"2024-09-18T00:00:00Z","timestamp":1726617600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Key Research and Development Special Fund of Qingdao Technical College","award":["2021ZDYF 04"],"award-info":[{"award-number":["2021ZDYF 04"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>A phosphorus-containing compound, (oxybis(4,1-phenylene))bis(phenylphosphine oxide) (ODDPO), was successfully synthesized and used as a flame retardant for epoxy resin (EP). The results demonstrated that EP\/ODDPO, containing 1.2 wt% phosphorus, achieved a vertical burning V-0 rating, with a limited oxygen index value of 29.2%, indicating excellent flame retardancy. Comprehensive evaluations revealed that ODDPO exhibited both gas-phase and condensed-phase flame-retardant effects on EP, with a particularly notable barrier effect. In addition, the incorporation of ODDPO had a minimal negative impact on the glass transition temperature (Tg) and thermal stability of the EP matrix. Compared to unmodified EP (EP-0), the Tg value and initial decomposition temperature of EP\/ODDPO-1.2 decreased by only 7.6 \u00b0C and 10.0 \u00b0C, respectively. Moreover, the introduction of ODDPO significantly improved the hydrophobicity and water absorption resistance of epoxy materials, which is attributed to ODDPO\u2019s rigidity and symmetric structure, reducing water molecule permeation. Furthermore, the dielectric properties of ODDPO-modified EP samples were strengthened compared to EP-0, due to the ODDPO\u2019s symmetric structure reducing the polarity of the matrix. The above results indicated that ODDPO serves as an excellent flame retardant while enhancing other properties of the EP matrix, thereby contributing to the preparation and application of high-performance epoxy materials.<\/jats:p>","DOI":"10.3390\/polym16182635","type":"journal-article","created":{"date-parts":[[2024,9,18]],"date-time":"2024-09-18T09:43:13Z","timestamp":1726652593000},"page":"2635","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Facile Synthesis of Bis-Diphenylphosphine Oxide as a Flame Retardant for Epoxy Resins"],"prefix":"10.3390","volume":"16","author":[{"given":"Yan","family":"Li","sequence":"first","affiliation":[{"name":"School of Biological and Chemical Engineering, Qingdao Technical College, Qingdao 266555, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chong","family":"Tian","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guiqing","family":"Cheng","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chunhui","family":"Li","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0427-4116","authenticated-orcid":false,"given":"Zhongwei","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"107420","DOI":"10.1016\/j.polymertesting.2021.107420","article-title":"Recyclable and reformable epoxy resins based on dynamic covalent bonds\u2013Present, past, and future","volume":"105","author":"Memon","year":"2022","journal-title":"Polym. 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