Xie Weiqi, Huang Shiwen, Liu Shumei, Zhao Jianqing
School of Materials Science and Engineering, South China University of Technology Guangzhou 510640 P. R. China
Key Laboratory of Polymer Processing Engineering, Ministry of Education Guangzhou 510640 P. R. China.
RSC Adv. 2019 Sep 30;9(53):30815-30822. doi: 10.1039/c9ra06574a. eCollection 2019 Sep 26.
Herein, a new renewable Schiff base flame retardant 4,4'-((1,1')-((oxybis(4,1-phenylene))bis(azanylylidene))bis(methanylylidene))bis(benzene-1,2-diol) (PH-ODA) was prepared by the reaction of protocatechualdehyde with 4,4'-diaminodiphenyl ether (ODA). PH-ODA (acting as a carbonization agent) combined with ammonium polyphosphate (APP) were used as intumescent flame retardants for commercial bisphenol A epoxy resin (DGEBA). For the cured epoxy resin containing 7.5% APP and 2.5% PH-ODA, the limiting oxygen index (LOI) reached 29.9% (with the V-0 rating in UL-94 test), and the peak heat release rate and total smoke production were respectively decreased by 88.1% and 68.3%, compared with pure epoxy resin. The enhancement of fire-safety performance was due to PH-ODA/APP promoting the formation of a compact intumescent char structure. It was also found that the synergism between PH-ODA and APP was helpful to enhance the fire resistance of the epoxy matrix. This work provides a facile and sustainable route for synthesizing Schiff base compounds from biomass-derived resources, possessing great potential for application in highly-effective intumescent flame retardants.
在此，通过原儿茶醛与4,4'-二氨基二苯醚（ODA）反应制备了一种新型可再生席夫碱阻燃剂4,4'-((1,1')-((氧双(4,1-亚苯基))双(氮亚基))双(亚甲基))双(苯-1,2-二醇)（PH-ODA）。PH-ODA（作为碳化剂）与聚磷酸铵（APP）组合用作商业双酚A环氧树脂（DGEBA）的膨胀型阻燃剂。对于含有7.5% APP和2.5% PH-ODA的固化环氧树脂，极限氧指数（LOI）达到29.9%（在UL-94测试中达到V-0等级），与纯环氧树脂相比，峰值热释放速率和总产烟量分别降低了88.1%和68.3%。防火性能的提高归因于PH-ODA/APP促进了致密膨胀炭结构的形成。还发现PH-ODA与APP之间的协同作用有助于提高环氧基体的耐火性。这项工作为从生物质衍生资源合成席夫碱化合物提供了一种简便且可持续的途径，在高效膨胀型阻燃剂中具有巨大的应用潜力。
