{"title":"Synthesis of phosphorus containing magnolol epoxy monomer and its flame retardant modification on bisphenol A epoxy resin","authors":"Baolong Li, Mingyuan Wang, Keyu Wang, Bingbing Wei, Gui Xiang Hou","doi":"10.1007/s10965-025-04523-9","DOIUrl":null,"url":null,"abstract":"<div><p>To enhance the flame retardancy of epoxy resin and incorporate biomass resources, a novel phosphorus-containing magnolol-based epoxy monomer (MG-DO-EP) was synthesized through a two-step reaction using magnolol and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as starting materials. The resulting monomer was then used as an intrinsic flame-retardant modifier in a composite thermosetting system, where it was co-cured with bisphenol A epoxy resin (E44) using 4,4’-diaminodiphenylmethane (DDM) as the curing agent. Comprehensive characterization revealed that the incorporation of MG-DO-EP significantly improved the material’s performance. Compared with unmodified E44/DDM, the MG-DO-EP-modified composites exhibited enhanced thermal stability, flame retardancy, flexural strength, and storage modulus, though with a slight reduction in glass transition temperature and crosslinking density. At a dosage of 20 wt%, the bending strength of the composite resin increased by 14.1%, while the storage modulus increased by 29.9%. The carbon residue at 700 ° C reached 56.7%, which is 3.57 times higher than that of the pure E44 system. Additionally, the peak heat release rate (pHRR) and total heat release (THR) decreased dramatically by 80.8% and 69.4%, respectively. At 10 wt% loading, the impact strength improved by 14.4% to 4.75 kJ/m². Notably, even at a low loading of 5 wt%, the composite achieved a V-0 rating in the UL-94 vertical burning test, demonstrating a synergistic flame-retardant mechanism involving both condensed-phase and gas-phase actions. These findings highlight the potential of MG-DO-EP as a sustainable and effective flame-retardant modifier for epoxy resins, offering balanced mechanical properties and superior fire resistance.</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":"32 9","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Polymer Research","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s10965-025-04523-9","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
To enhance the flame retardancy of epoxy resin and incorporate biomass resources, a novel phosphorus-containing magnolol-based epoxy monomer (MG-DO-EP) was synthesized through a two-step reaction using magnolol and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as starting materials. The resulting monomer was then used as an intrinsic flame-retardant modifier in a composite thermosetting system, where it was co-cured with bisphenol A epoxy resin (E44) using 4,4’-diaminodiphenylmethane (DDM) as the curing agent. Comprehensive characterization revealed that the incorporation of MG-DO-EP significantly improved the material’s performance. Compared with unmodified E44/DDM, the MG-DO-EP-modified composites exhibited enhanced thermal stability, flame retardancy, flexural strength, and storage modulus, though with a slight reduction in glass transition temperature and crosslinking density. At a dosage of 20 wt%, the bending strength of the composite resin increased by 14.1%, while the storage modulus increased by 29.9%. The carbon residue at 700 ° C reached 56.7%, which is 3.57 times higher than that of the pure E44 system. Additionally, the peak heat release rate (pHRR) and total heat release (THR) decreased dramatically by 80.8% and 69.4%, respectively. At 10 wt% loading, the impact strength improved by 14.4% to 4.75 kJ/m². Notably, even at a low loading of 5 wt%, the composite achieved a V-0 rating in the UL-94 vertical burning test, demonstrating a synergistic flame-retardant mechanism involving both condensed-phase and gas-phase actions. These findings highlight the potential of MG-DO-EP as a sustainable and effective flame-retardant modifier for epoxy resins, offering balanced mechanical properties and superior fire resistance.
期刊介绍:
Journal of Polymer Research provides a forum for the prompt publication of articles concerning the fundamental and applied research of polymers. Its great feature lies in the diversity of content which it encompasses, drawing together results from all aspects of polymer science and technology.
As polymer research is rapidly growing around the globe, the aim of this journal is to establish itself as a significant information tool not only for the international polymer researchers in academia but also for those working in industry. The scope of the journal covers a wide range of the highly interdisciplinary field of polymer science and technology, including:
polymer synthesis;
polymer reactions;
polymerization kinetics;
polymer physics;
morphology;
structure-property relationships;
polymer analysis and characterization;
physical and mechanical properties;
electrical and optical properties;
polymer processing and rheology;
application of polymers;
supramolecular science of polymers;
polymer composites.