Fe_(3)O_(4)-MoS_(2)协同改性环氧树脂涂层的制备及耐磨防腐性能研究

Fe_(3)O_(4)-MoS_(2) Nanohybrid for Enhancing Wear Resistance and Anticorrosion Performance of Epoxy Coatings

目的解决油气装备管道面临的腐蚀磨损等失效问题。方法使用不同物质的量比的纳米Fe_(3)O_(4)、MoS_(2)通过硅烷偶联剂(APTES)结合为杂化填料,并将其填充至环氧树脂(EP)中,制备出复合涂层。利用扫描电镜(SEM)、X射线衍射仪(XRD)及傅里叶红外光谱(FT-IR)对杂化填料的显微结构、物相组成及成分进行了分析。同时,利用分散稳定性试验、显微维氏硬度、往复摩擦试验、表面轮廓测试、吸水率及接触角测试、电化学阻抗谱及动电位极化曲线综合评价复合涂层耐磨及防腐蚀性能。结果Fe_(3)O_(4)-MoS_(2)纳米杂化物在环氧树脂中具有良好的分散稳定性。与Fe_(3)O_(4)/EP、MoS_(2)/EP相比,Fe_(3)O_(4)-MoS_(2)/EP复合涂层的显微硬度与耐磨性提高,同时其耐水性和防腐性能也得到增强。当Fe_(3)O_(4)-MoS_(2)物质的量比为1∶5时,复合涂层摩擦因数最低为0.337,相比于纯EP降低34.56%。当Fe_(3)O_(4)-MoS_(2)物质的量比为1∶1,复合涂层阻抗值最高,并且显示出最大的腐蚀电位(E_(corr))和最小的腐蚀电流(Jcorr),Fe_(3)O_(4)-MoS_(2)/EP涂层的阻抗(Rc)提高了近2个数量级。结论Fe_(3)O_(4)-MoS_(2)是可用于制备高性能环氧耐磨防腐涂料的有效的纳米填料。复合涂料优异的减摩性得益于Fe_(3)O_(4)颗粒的纳米球滚动润滑效应和MoS_(2)片的滑移效应,而其高防腐性能归功于Fe_(3)O_(4)-MoS_(2)良好的分散性和阻隔性。

To improve the low corrosion and wear resistance caused by micro-pores in epoxy resin,nano-Fe_(3)O_(4) was used as a filler to modify the epoxy resin.However,considering the poor dispersion and easy aggregation of the nano-Fe_(3)O_(4) filler,this study used a silane coupling agent(APTES)to modify Fe_(3)O_(4) and connect it to the lubricating layered molybdenum disulfide.Q235 steel was used as the substrate,polished and cleaned with sandpaper,and 1 wt.%Fe_(3)O_(4)-MoS_(2) with different molar ratios(3:1,1:1,1:3,1:5 and 1:7)was added to the epoxy resin to prepare composite coatings.The microstructure and phase composition of the hybrid filler were analyzed by transmission electron microscopy(TEM),scanning electron microscopy(SEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(Nicolet 6700).The dispersion of the filler in the epoxy resin was observed with a stereomicroscope(OM),and the microhardness of the coating was tested with a micro Vickers hardness tester(HV-1000STA).Wear tests were conducted on the surface multifunctional testing machine(MFT-4000),and the morphology of wear marks was observed and elemental analysis was performed.The corrosion resistance of the coating was comprehensively evaluated by water absorption rate,contact angle test,electrochemical impedance spectroscopy(EIS),and potentiodynamic polarization tests.Fe_(3)O_(4)-MoS_(2) nanohybrids were successfully prepared,in which the nano Fe_(3)O_(4) was uniformly anchored onto MoS_(2).It exhibited good dispersion stability in epoxy resin.Compared with Fe_(3)O_(4)/EP and MoS_(2)/EP,the Fe_(3)O_(4)-MoS_(2)/EP composite coating had higher microhardness and anti-ploughing ability.When the molar ratio of Fe_(3)O_(4) to MoS_(2) was 3:1,the maximum coating hardness was 16.19HV,it was increased by 11.2%compared with pure EP.Additionally,the nano-ball bearing effect of Fe_(3)O_(4) nanoparticles and the slip effect of MoS_(2) flakes worked together to reduce the friction coefficient of Fe_(3)O_(4)-MoS_(2)/EP.This led to a narrower wear track,weakened adhesive wear and fatigue wear,and ultimately improved wear resistance.When Fe_(3)O_(4)-MoS_(2)(1:5)was added,the friction coefficient of the composite coating was the lowest,reaching 0.337,which was 34.56%lower than pure EP.In addition,Fe_(3)O_(4)-MoS_(2) formed a covalent bond with silane which improved its adhesion with the coating.This also filled the coating pores and increased the cross-linking density of the coating,reducing the likelihood of corrosive ion diffusion to the coating/metal interface.Fe_(3)O_(4)-MoS_(2) also had excellent dispersion and barrier properties that further improved its water and corrosion resistance.When adding Fe_(3)O_(4)-MoS_(2)(1:1),the water absorption rate of the composite coating was minimized at 0.712%,which was reduced by 26.06%compared with pure EP.At the same time,the contact angle reached the maximum value of 89°.At this time,the impedance value of the composite coating was the highest,and it exhibited the maximum value(E_(corr))and the minimum value(Jcorr).Compared with EP coatings,the Rc of Fe_(3)O_(4)-MoS_(2)/EP coatings was increased by nearly two orders of magnitude.Nano Fe_(3)O_(4) and layered MoS_(2) play a synergistic role in wear resistance and corrosion protection,providing a controllable and effective strategy for developing nanofiller/epoxy resin composite coatings with enhanced wear resistance and corrosion performance.