{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T03:43:28Z","timestamp":1791171808564,"version":"4.1.0"},"reference-count":43,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2024,6,21]],"date-time":"2024-06-21T00:00:00Z","timestamp":1718928000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Guangxi Science and Technology Major Project","award":["AA23062008-1"],"award-info":[{"award-number":["AA23062008-1"]}]},{"name":"Guangxi Science and Technology Major Project","award":["2020GXNSFGA297004"],"award-info":[{"award-number":["2020GXNSFGA297004"]}]},{"name":"Guangxi Natural Science Foundation","award":["AA23062008-1"],"award-info":[{"award-number":["AA23062008-1"]}]},{"name":"Guangxi Natural Science Foundation","award":["2020GXNSFGA297004"],"award-info":[{"award-number":["2020GXNSFGA297004"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Urea\u2013formaldehyde (UF) resin is the most widely used adhesive resin. However, it is necessary to improve its flame-retardant performance to expand its applications. In this study, exploiting electrostatic interactions, anionic phytic acid and cationic chitosan were combined to form a bio-based intumescent flame-retardant, denoted phytic acid\u2013chitosan polyelectrolyte (PCS). The molecular structure of the urea\u2013formaldehyde resin was optimized by crosslinking with melamine and plasticizing with polyvinyl alcohol-124. Thus, by combining PCS with the urea\u2013formaldehyde resin and with ammonium polyphosphate and ammonium chloride as composite curing agents, flame-retardant urea\u2013formaldehyde resins (FRUFs) were prepared. Compared to traditional UF resin, FRUF showed excellent flame retardancy and not only reached the UL-94 V-0 level, but the limit of oxygen index was also as high as 36%. Compared to those of UF, the total heat release and peak heat release rate of FRUF decreased by 86.44% and 81.13%, respectively. The high flame retardancy of FRUF originates from the combination of oxygen and heat isolation by the dense carbon layer, quenching of phosphorus free radicals, and dilution of oxygen by a non-flammable gas. In addition, the mechanical properties of the FRUF remained good, even after modification. The findings of this study provide a reference for the flame-retardant application of FRUF for applications in multiple fields.<\/jats:p>","DOI":"10.3390\/polym16131761","type":"journal-article","created":{"date-parts":[[2024,6,21]],"date-time":"2024-06-21T08:50:08Z","timestamp":1718959808000},"page":"1761","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":28,"title":["Preparation of a Highly Flame-Retardant Urea\u2013Formaldehyde Resin and Flame Retardance Mechanism"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-9510-9155","authenticated-orcid":false,"given":"An","family":"Wei","sequence":"first","affiliation":[{"name":"College of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China"},{"name":"Nanning Guidian Electronic Technology Research Institute Co., Ltd., Nanning 530000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-7726-1124","authenticated-orcid":false,"given":"Meifeng","family":"Ou","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shunxiang","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China"},{"name":"Nanning Guidian Electronic Technology Research Institute Co., Ltd., Nanning 530000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9012-2639","authenticated-orcid":false,"given":"Yongjin","family":"Zou","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China"},{"name":"Nanning Guidian Electronic Technology Research Institute Co., Ltd., Nanning 530000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cuili","family":"Xiang","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2900-1325","authenticated-orcid":false,"given":"Fen","family":"Xu","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4684-683X","authenticated-orcid":false,"given":"Lixian","family":"Sun","sequence":"additional","affiliation":[{"name":"College of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1157","DOI":"10.1021\/acsapm.0c01362","article-title":"Highly Branched Polyurea-Enhanced Urea-Formaldehyde Resin","volume":"3","author":"Jiang","year":"2021","journal-title":"ACS Appl. 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