氧化石墨烯-水性环氧树脂固化剂的制备及性能

Preparation and properties of GO-water based epoxy resin curing agent

首先,将三乙烯四胺(TETA)和氧化石墨烯(GO)球磨,得到TETA改性GO分散液TGO;然后向其中依次滴加双酚A型环氧树脂E44、三羟甲基丙烷三缩水甘油醚(TPEG)、甲氧基聚氧乙烯-2,3-环氧丙烷(MEH)和γ-(2,3-环氧丙氧基)丙基三甲氧基硅烷(KH560),采用原位聚合法合成了氧化石墨烯-水性环氧树脂固化剂(TGO-WPEA);采用上述工艺,不添加GO的条件下制得水性环氧树脂固化剂(WPEA)。将WPEA和TGO-WPEA分别与环氧树脂乳液(Epikote-6520)复合制得水性环氧树脂(EP)和氧化石墨烯改性水性环氧树脂(TGO-EP)防腐涂料。通过FTIR、XPS和XRD对材料进行了结构表征,采用电化学测试和盐雾实验对TGO-EP的防腐性能进行了评价。结果表明,水性环氧树脂固化剂(WPEA)分子通过共价键连接到GO表面,改善了GO在EP中的分散稳定性和接枝率,提高了TGO-EP复合涂料对腐蚀介质的屏蔽性能。与纯EP涂层相比,TGO-EP涂层腐蚀电位从-0.267 V提高到-0.125 V,腐蚀电流密度从5.44×10^(-8)A/cm^(2)减小到1.09×10^(-8)A/cm^(2);浸泡20 d后,TGO-EP仍具有较高的低频阻抗。

Triethylenetetramine(TETA)-modified graphene oxide(GO)dispersion was prepared from ball-milled TETA and GO,into which epoxy resin E44,trimethylolpropane triglycidyl ether(TPEG),methoxypolyoxyethylene,2,3-propylene oxide(MEH)andγ-(2,3-epoxypropoxy)propytrimethosysilane(KH560)were dripped to form the water-based epoxy resin curing agent(TGO-WPEA)via in situ polymerization.The water-based epoxy resin curing agent(WPEA)was prepared by the above process without adding GO.The waterborne epoxy resin anti-corrosion coating(EP)and graphene oxide modified waterborne epoxy resin anti-corrosion coating(TGO-EP)anti-corrosion coatings were prepared by WPEA and TGO-WPEA combined with epoxy resin emulsion(Epikote-6520),respectively.The structure of the materials was characterized by FTIR,XPS and XRD,while the corrosion resistance performance of TGO-EP was evaluated via electrochemical tests and salt spray experiments.The results showed that TGO-WPEA molecules were covalently linked to the surface of GO,which improved the dispersion stability and grafting rate of GO in epoxy resin(EP)as well as the shielding performance of TGO-EP composite coatings against corrosive media.Compared with those of pure EP coating,the corrosion potential of TGO-EP composite coating was increased from-0.267 V to-0.125 V,the corrosion current density decreased from 5.44×10^(-8)A/cm^(2)to 1.09×10^(-8)A/cm^(2).TGO-EP still retained high low-frequency impedance after 20 d of immersion.