通过两步法将含磷基团的9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)和含硅基团的硅烷偶联剂引入氧化石墨烯(GO)中,制备了磷硅协同改性的氧化石墨烯(KDGO),通过傅里叶变换红外(FT-IR)光谱、能谱散射谱(EDS)、X射线衍射(XRD)和原子力显微镜(AFM)分析对其进行表征,并将其添加到环氧树脂(EP)中进行阻燃改性,制备EP基复合材料KDGO/EP.采用热重分析(TGA)、动态热机械分析(DMA)、极限氧指数(LOI)和垂直燃烧测试复合材料的热稳定性、动态热机械性能和阻燃性能.TGA结果表明,质量分数为1%的KDGO能够保持复合材料的热稳定性,同时提高残炭率,与纯EP固化物相比,残炭率提高了10个百分点,解决了目前市场上含DOPO阻燃剂引起固化材料热稳定性下降的问题.DMA数据显示,KDGO中的环氧基能够参与EP的交联固化,使复合材料的动态热机械性能提高,有效改善了由DOPO引起的动态热机械性能下降的问题.LOI和垂直燃烧测试表明磷硅阻燃元素的协同作用有助于提高复合材料的阻燃性能,使LOI值提高到27.1%,燃烧过程无滴落现象,达到了塑料阻燃等级V-0级.
We introduced the phosphorus group,9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO),and the silicon group,a silane coupling agent,into graphene oxide(GO)to prepare phosphorus and silicon modified graphene oxide(KDGO).And it was characterized using Fourier transform infrared(FT-IR)spectroscopy,energy disperse spectroscopy(EDS),X-ray diffraction(XRD),and atomic force microscope(AFM).Then KDGO was added into epoxy resin(EP)to prepare epoxy resin composite material(KDGO/EP).The thermal stability,dynamic thermal mechanical properties,and flame retarded properties of epoxy composites were tested using thermogravimetric analysis(TGA),dynamic mechanical analysis(DMA),limit oxygen index(LOI)and vertical burning test.The results of TGA showed that the presence of silicon in KDGO could effectively improve the thermal stability of EP curing which decreased due to the oxygen groups of GO and phosphorus oxygen groups of DOPO,and the carbon residue increased by 10 percentage points compared with the pure EP curing at the same time.This solves the problem of the thermal stability decline of the curing material caused by DOPO-containing flame retardant in the present market.DMA data showed that the epoxy group of KDGO which could attend the crosslinking reaction with EP could effectively improve the dynamic thermal mechanical properties.LOI and vertical burning tests showed that the flame retarded elements,phosphorus and silicon,increased the flame retardancy of the material.The LOI value of 1%KDGO/EP increased to 27.1%,no dripping phenomenon was observed,and the plastic flame retardant level of V-0 was reached.
