阻燃杂化纳米粒子改性环氧树脂

Flame Retardant Hybrid Nanoparticles Modified Epoxy

以甲基丙烯酸DOPO乙酯(HEPO)和甲基丙烯酸缩水甘油酯(GMA)共聚合成了PHEPO-b-PGMA(PHDG)嵌段共聚物,将其接枝于氨基改性的SiO_2纳米粒子表面,获得新型阻燃SiO_2-PHDG核壳结构杂化纳米粒子。将SiO_2-PHDG引入到双酚A型环氧树脂E51中,制备了一系列P,Si含量可调的阻燃改性环氧树脂。采用扫描电镜和透射电镜对SiO_2-PHDG、改性环氧树脂断面及烧蚀后炭层进行形貌分析;动态力学分析、热重分析、差示扫描量热法及极限氧指数(LOI)研究表明,SiO_2-PHDG可使阻燃元素P,Si以"捆绑式"较好地分散在环氧树脂基体中,在较低P,Si含量下表现出优良的协同阻燃效果,当SiO2-PHDG的添加量为8%时,改性环氧树脂的LOI由26.0上升到32.8。此外,添加适量的SiO_2-PHDG可一定程度上提高环氧树脂的热稳定性及力学性能。

A novel 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide（ DOPO） ethyl methacrylate and glycidyl methacrylate block copolymer PHEPO-b-PGMA（ PHDG） containing phosphorus and epoxy group were prepared and grafted on the surface of SiO2-NH2,thereby resulting in a new type of flame retardant SiO_2-PHDG core-shell nanoparticles.A series of flame retardant epoxy resins composed of different contents of phosphorus and silicon were prepared by mixing SiO_2-PHDG with diglycidyl ether of bisphenol-A（ E51）. The morphology of SiO-2-PHDG,fracture surfaces and charcoal layer after burning of the flame retardant epoxy resins were studied by SEM and TEM. Properties of the flame retardant epoxy resins were evaluated by dynamic thermomechanical analysis（ DMA）,thermogravimetric analysis（ TGA）,differential scanning calorimetry（ DSC）,and limiting oxygen index（ LOI）. The results show that SiO_2-PHDG could form core-shell structure in E51 with SiO_2 nanoparticles as core,and phosphorus-containing block PHDG as shell. Retardant elements P,Siare homogeneously dispersed in epoxy matrix with＂bundled＂form,which lead to an excellent synergistic flame retardant effect at a low P and Sicontent. When the addition of SiO_2-PHDG reaches 8%,the LOI of modified epoxy resins increases from about 26. 0 to 32. 8. In addition,a certain amount of SiO_2-PHDG could improve both the flame retardant performance and mechanical properties of epoxy resin.