{"title":"Effect of aluminum diisobutyl hypophosphate in polyethylene terephthalate and its flame retardant mechanism","authors":"Yushu Xiang, Yun Gao, Guomin Xu, Wentao He, Lijuan Long, Shuhao Qin, Jie Yu","doi":"10.1002/vnl.22083","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <p>Alkyl hypophosphate flame retardants have aroused intense research interests in flame retardancy of polymers owing to the combined effect of gas phase and condensed phase. In this work, aluminum diisobutyl hypophosphate (APBA) was incorporated into polyethylene glycol terephthalate (PET) to investigate its flame retardant effect and mechanism. PET achieved a V-2 level in UL-94, with a low LOI of 21.2%. In contrast, PET/APBA-15% composites showed a 51% increase of LOI value and a V-0 level, accompanied with the significant reduction of melt droplets. Gas phase analysis by Py-GC/MS and TG-FTIR indicated that the phosphorous free radicals and nonflammable gases were generated during the cracking of APBA, resulting in the radical quenching and dilution of combustible gas. Condensed phase analysis by SEM, Raman, and XPS results revealed that APBA could effectively facilitate the formation of dense char layers consisting of aluminophosphate and graphitic structures due to the interaction with PET matrix. The compact barrier layer could insulate heat and inhibit the volatilization of combustible materials, leading to improved flame retardant properties. Furthermore, the introduction of APBA increased the melt viscosity of PET/APBA composites according to rheological analysis, which further promoted the formation of a char barrier layer to further enhance the flame retardant properties.</p>\n </section>\n \n <section>\n \n <h3> Highlights</h3>\n \n <div>\n <ul>\n \n <li>Aluminum diisobutyl hypophosphate is used as an efficient flame retardant for PET.</li>\n \n <li>The flame retardant can degrade to release the phosphorous free radicals.</li>\n \n <li>The flame retardant can interact with the PET matrix and promote the charring.</li>\n </ul>\n </div>\n </section>\n </div>","PeriodicalId":17662,"journal":{"name":"Journal of Vinyl & Additive Technology","volume":null,"pages":null},"PeriodicalIF":3.8000,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Vinyl & Additive Technology","FirstCategoryId":"88","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/vnl.22083","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
Alkyl hypophosphate flame retardants have aroused intense research interests in flame retardancy of polymers owing to the combined effect of gas phase and condensed phase. In this work, aluminum diisobutyl hypophosphate (APBA) was incorporated into polyethylene glycol terephthalate (PET) to investigate its flame retardant effect and mechanism. PET achieved a V-2 level in UL-94, with a low LOI of 21.2%. In contrast, PET/APBA-15% composites showed a 51% increase of LOI value and a V-0 level, accompanied with the significant reduction of melt droplets. Gas phase analysis by Py-GC/MS and TG-FTIR indicated that the phosphorous free radicals and nonflammable gases were generated during the cracking of APBA, resulting in the radical quenching and dilution of combustible gas. Condensed phase analysis by SEM, Raman, and XPS results revealed that APBA could effectively facilitate the formation of dense char layers consisting of aluminophosphate and graphitic structures due to the interaction with PET matrix. The compact barrier layer could insulate heat and inhibit the volatilization of combustible materials, leading to improved flame retardant properties. Furthermore, the introduction of APBA increased the melt viscosity of PET/APBA composites according to rheological analysis, which further promoted the formation of a char barrier layer to further enhance the flame retardant properties.
Highlights
Aluminum diisobutyl hypophosphate is used as an efficient flame retardant for PET.
The flame retardant can degrade to release the phosphorous free radicals.
The flame retardant can interact with the PET matrix and promote the charring.
期刊介绍:
Journal of Vinyl and Additive Technology is a peer-reviewed technical publication for new work in the fields of polymer modifiers and additives, vinyl polymers and selected review papers. Over half of all papers in JVAT are based on technology of additives and modifiers for all classes of polymers: thermoset polymers and both condensation and addition thermoplastics. Papers on vinyl technology include PVC additives.