The Key Laboratory of Polymer Processing Engineering of Ministry of Education, South China University of Technology, Guangzhou 510640, China; Department of Industrial Equipment and Control Engineering, South China University of Technology, Guangzhou 510640, China.
College of Electro Mechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, China.
J Colloid Interface Sci. 2018 Aug 15;524:267-278. doi: 10.1016/j.jcis.2018.04.016. Epub 2018 Apr 6.
The fabrication of biodegradable polymer nanocomposites with improved flame retardancy has been an urgent task in practical because of the huge benefits of biodegradable polymers. In this work, 10-(2,5-dihydroxyl phenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ)-functionalized graphene oxide (GO) (FGO-HQ) was used as a novel and highly efficient flame retardant (FR) to improve the flame retardancy of polylactide (PLA) nanocomposites. Contributed by the bi-phase flame retardant action, including the physical barrier char in solid phase and the decreased flammable volatiles in gas phase, the resultant PLA/FGO-HQ nanocomposites presented excellent flame resistance at the loading of 6 wt% FR: UL-94 reached V-0 rating; peak heat release rate (PHRR) and total heat release (THR) decreased by 24.0% and 43.0%, respectively; smoke production rate (SPR) and total smoke release (TSR) decreased by 46% and 83%, respectively. For further confirming its flame-resistance mechanism, thermogravimetric analysis/infrared spectrometry (TG-IR) and Fourier transform infrared spectra (FT-IR), scanning electron microscope (SEM), and Raman spectroscopy were employed. Results indicated that the incorporation of FGO-HQ can effectively reduce the evaporation of flammable gaseous product in gas phase through quenching free radicals. Meanwhile, graphitized carbons are formed in the residual char and PLA/FGO-HQ sample can achieve a good thermal stability in the combustion with phosphorus-containing compounds and aromatic structure in the solid phase. Furthermore, the tensile strength of PLA nanocomposites presented good mechanical properties with the addition of FR as well. These results suggested that the incorporation of FGO-HQ FR not only improve the flame retardancy and thermal stability of biodegradable polymer nanocomposites but also without sacrificing their mechanical properties.
具有改善的阻燃性的可生物降解聚合物纳米复合材料的制造一直是实际中的一项紧迫任务，因为可生物降解聚合物具有巨大的益处。在这项工作中，使用 10-(2,5-二羟基苯基)-9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO-HQ)-官能化氧化石墨烯(GO)(FGO-HQ)作为一种新型且高效的阻燃剂(FR)来提高聚乳酸(PLA)纳米复合材料的阻燃性。由于双相阻燃作用，包括固相中的物理阻隔炭和气相中减少的易燃挥发物，所得的 PLA/FGO-HQ 纳米复合材料在 6 wt% FR 负载下表现出优异的阻燃性：UL-94 达到 V-0 等级;峰值热释放率(PHRR)和总热释放量(THR)分别降低了 24.0%和 43.0%;烟释放率(SPR)和总烟释放量(TSR)分别降低了 46%和 83%。为了进一步证实其阻燃机理，采用热重分析/红外光谱(TG-IR)和傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)和拉曼光谱进行了研究。结果表明，FGO-HQ 的加入可以通过猝灭自由基有效地减少气相中易燃气态产物的蒸发。同时，在残炭中形成了石墨化碳，并且在燃烧过程中含磷化合物和固相中的芳构结构使 PLA/FGO-HQ 样品具有良好的热稳定性。此外，随着 FR 的加入，PLA 纳米复合材料的拉伸强度也表现出良好的机械性能。这些结果表明，FGO-HQ FR 的加入不仅可以提高可生物降解聚合物纳米复合材料的阻燃性和热稳定性，而且不会牺牲其机械性能。
