ZrO_2掺杂电泳漆环氧涂层的制备及防护性能

在电泳清漆环氧树脂中掺杂硝酸锆(Zr(NO3)4·5H2O),采用一步电泳法制备ZrO2掺杂改性的阴极电泳漆涂层,用于镀锌钢的腐蚀防护。红外测试表明,硝酸锆水解产物ZrO2与环氧树脂粒子共沉积构成阴极电泳涂层,并在涂层/金属界面发生富集。电化学阻抗谱、盐水浸泡和电化学扫描显微镜等结果表明,硝酸锆掺杂的电泳漆涂层防腐蚀性能得到大幅度提高。这可能是由于一方面掺杂形成的ZrO2填补了涂层本体的微孔缺陷,另一方面ZrO2在涂层与金属界面形成的富集层提高了涂层与金属之间的结合力。     

添加纳米锌粉环痒涂层腐蚀电化学行为

用电化学阻抗谱(EIS)技术研究了添加不同质量 百分比浓度的纳米锌粉环氧涂层的腐蚀电化学行为，并与环氧清漆(不含颜料)涂层的腐蚀电化学行为进行对比.结果表明，添加不同质量百分比浓度纳米锌粉环氧涂层与环氧清漆涂层具有不同的电化学阻抗谱特征.纳米锌粉的添加量对涂层的防护性能有显著影响，添加不同质量百分比浓度纳米锌粉环氧涂层防腐蚀性能的优劣顺序为：环氧清漆涂层>20mass%>10mass%>2mass%纳米锌环氧涂层.添加纳米锌粉对环氧涂层的防护性能有2方面的影响：一方面使涂层中的微观缺陷大大增多，涂层的防护性能降低；另一方面，由于锌粉的腐蚀产物可将涂层中部分缺陷堵塞，从而对涂层的防护性能有提高作用.由于在所研究的质量百分比浓度范围内(2mass%～20mass%)，前者起了主导作用，所以综合作用的结果是使涂层的防护性能变差.  s.     

硅烷处理对 EW75 M 稀土镁合金阴极电泳涂层性能的影响

目的探究硅烷处理对阴极电泳涂层的耐腐蚀性能及其与基体间结合力的影响。方法对稀土镁合金表面进行硅烷前处理,再沉积阴极电泳涂层,评价涂层的耐腐蚀性能、抗溶胀性能,分析涂层的腐蚀微观形貌、组织结构及界面结合。结果硅烷膜层具有一定的防护性能,能够减少阴极电泳涂层针孔、橘皮的出现,增强阴极电泳涂层的致密性。硅烷改性能够提高阴极电泳涂层与基体的结合力,硅烷预处理的电泳试样在NMP溶液中浸泡102 h,依然结合完好;而未经硅烷预处理的电泳试样浸泡7 min后,涂层就完全剥落。此外,硅烷处理能够极大地改善阴极电泳涂层的阻抗性能,使涂层在3.5%(质量分数)NaCl溶液中浸泡227 h的极化电阻Rp仍在108数量级以上。结论硅烷阴极电泳复合涂层具有良好的耐蚀性能和抗溶胀性能,值得推广应用。     

纳米二氧化钛硅烷接枝密度对水性环氧涂层耐蚀性能的影响

目的研究水性环氧/硅烷化纳米TiO2复合防护涂层在3.5%NaCl溶液中的失效规律和防腐性能。方法采用3-氨丙基三乙氧基硅烷(APTES)化学接枝改性纳米TiO2颗粒,将硅烷改性纳米TiO2均匀分散在水性环氧涂料中,并把混合涂料涂覆在Q235钢试样上。采用傅里叶红外光谱仪(FTIR)和热重分析仪(TGA)测试纳米TiO2表面化学接枝改性情况,采用电化学工作站测试复合涂层的电化学性能,采用激光共聚焦显微镜观察复合膜层的表面形貌。结果使用质量分数10%APTES改性纳米TiO2,单齿螺旋结构占有的比例更高;使用质量分数20%APTES改性纳米TiO2,具有最高的接枝密度,为11.78 APTES/nm^2。电化学测试结果显示,环氧/TiO2复合涂层比纯环氧涂层具有更好的耐蚀性能,其中加入质量分数20%APTES改性纳米TiO2的环氧/TiO2复合涂层对基体的保护性能最好,其涂层电阻是纯环氧涂层的12倍,电荷转移电阻是纯环氧涂层的18倍。在相同的腐蚀条件下,单齿螺旋结构更容易被破坏。加入硅烷纳米TiO2颗粒后,可以显著减少涂层表面尖峰状突起和孔洞。结论纳米TiO2的APTES接枝分子密度,是水性环氧/硅烷化纳米TiO2复合防护涂层耐腐蚀性能提高的直接原因。     

铈盐掺杂GPTMS/TEOS硅烷杂化膜腐蚀电化学行为随时间的变化

以γ-环氧丙氧丙基三甲氧基硅烷(GPTMS)和正硅酸乙酯(TEOS)为前躯体,采用溶胶-凝胶法在LY12铝合金基体表面制备了铈盐Ce(NO3)3掺杂有机-无机杂化膜。通过极化曲线与电化学阻抗谱(EIS)研究铈盐掺杂硅烷杂化膜在3.5%(质量分数)NaCl溶液中耐蚀性能随浸泡时间的变化。结果表明,硅烷杂化膜的极化阻抗值随浸泡时间延长而缓慢降低,但浸泡183 h后仍显著高于金属基体;铝合金点蚀电位在浸泡期间呈现先降低后升高再降低的变化。在浸泡初期,EIS曲线的高频容抗行为显著。从69 h至260 h浸泡试验结束,低频阻抗值保持基本稳定。上述变化与膜中掺杂的铈盐具有自修复性质密切相关。     

The electrochemical study of corrosion resistance of silane-based hybrid films doped with rare earth salt on aluminum alloy

采用溶胶-凝胶法, 以γ-环氧丙氧丙基三甲氧基硅烷(γ-GPTMS)和正硅酸乙酯 (TEOS)为前驱体, 在2A12铝合金表面制备了稀土铈盐(Ce(NO3)3)掺杂的有机－无机杂化膜, 研究了铈盐掺杂浓度和涂层固化温度等工艺条件. 通过极化曲线和电化学阻抗谱(EIS), 比较了掺杂与未掺杂有机－无机硅烷杂化膜、铬酸盐转化膜和RE转化膜在3.5%NaCl (质量分数)溶液中的耐腐蚀性能. 测试结果均表明, 铈盐掺杂硅烷杂化膜的极化电阻比掺杂前增大了约13倍,并显著高于铬酸盐转化膜和RE转化膜.     

碳黑掺杂型导电有机涂层的防护机制

 利用碳黑掺杂的方法制备熔融结合环氧(FBE)导电涂层，选用电化学阻抗谱法(EIS)、热重分析(TGA)和差示扫描量热(DSC)等手段研究了其在3%NaCl溶液中失效过程及防护机制.结果表明:与相应的含有少量碳黑的绝缘FBE涂层相比,导电FBE涂层体系的防护性能显著提高,这得益于导电涂层中碳黑连续网络增加了腐蚀介质的传输阻力；对涂层保护下金属基材腐蚀形貌的分析均证明了此结论.        

430不锈钢表面GPTMS/PFDS自组装双层膜的制备及缓蚀性能

在430不锈钢表面制备了γ-缩水甘油醚氧丙基三甲氧基硅烷(GPTMS)/全氟癸基三乙氧基硅烷(PFDS)自组装双层膜。采用傅里叶变换红外光谱、电化学测试、接触角和SEM研究了自组装膜的吸附及对不锈钢电极的缓蚀性能。结果表明,GPTMS/PFDS双层膜比GPTMS单层膜和PFDS单层膜具有更优异的抗腐蚀性能。     

2A12铝合金表面铈盐掺杂硅烷杂化膜在3.5%NaCl溶液中耐蚀性能的电化学研究

采用溶胶-凝胶法,以γ-环氧丙氧丙基三甲氧基硅烷(γ-GPTMS)和正硅酸乙酯(TEOS)为前驱体,在2A12铝合金表面制备了稀土铈盐(Ce(NO3)3)掺杂的有机-无机杂化膜,研究了铈盐掺杂浓度和涂层固化温度等工艺条件.通过极化曲线和电化学阻抗谱(EIS),比较了掺杂与未掺杂有机-无机硅烷杂化膜、铬酸盐转化膜和RE转化膜在3.5%NaCl(质量分数)溶液中的耐腐蚀性能.测试结果均表明,铈盐掺杂硅烷杂化膜的极化电阻比掺杂前增大了约13倍,并显著高于铬酸盐转化膜和RE转化膜.     

Ti纳米粒子对环氧涂层防护性能的影响

应用电化学阻抗法(EIS)、示扫描量热法(DSC)、X射线光电子谱(XPS)研究了添加Ti纳米粒子对环氧涂层防护性能的影响.结果表明:添加Ti纳米粒子可以提高环氧涂层的防护性能,添加量在0.5%(以w/w计)时最好.这是由于添加Ti纳米粒子虽然可增加涂层孔隙率,但Ti纳米粒子与环氧树脂之间存在的相互作用可改善涂层对腐蚀性介质的屏蔽性能,提高涂层的防护性能.     

Improving the corrosion performance of epoxy coatings by chemical modification with silane monomers

In this communication, commercial epoxy resins were chemically modified with various silane monomers under the catalysis of organotin compound, aiming to enhance the corrosion resistance of epoxy coatings on 2024-T3 aluminum substrates. Immersion studies conducted in 3.5 wt.% NaCl solution showed that the coating capacitance (C_c) decreases significantly after the silane modification, as measured by electrochemical impedance spectroscopy (EIS), indicating the higher resistance to water permeation. EIS measurements also indicated an enhancement in protectiveness of silane-modified epoxy coatings against substrate corrosion, which was characterized by higher charge transfer resistances (R_ct) and lower double layer capacitance (C_dl) at substrate/electrolyte interface. The adhesion of epoxy coatings was also found to improve after the modification with silane components. The best performance was observed for coating system modified by 3-glycidoxypropyltrimethoxy silane (GPTMS).     

有机覆膜对热烧结锌铝涂层耐腐蚀性能的影响

为提高热烧结锌铝涂层（简称锌铝涂层）的耐蚀性,在涂层表面涂覆一层环氧富铝膜,形成复合涂层。采用十字划格法测试锌铝涂层和复合涂层的附着强度,并用扫描电镜（SEM）分析涂层微观形貌;用海水全浸实验和中性盐雾实验评价涂层的耐蚀性能;采用动电位极化曲线和电化学阻抗谱（EIS）研究涂层的电化学性能。结果表明,复合涂层表面更为完整致密,防水性能优于锌铝涂层;环氧富铝膜层能够有效的阻挡腐蚀介质的入侵,复合涂层耐蚀性比锌铝涂层高。复合涂层腐蚀初期主要为扩散控制,随着腐蚀介质的不断渗入,环氧膜层中的Al粉发生活化反应,起到了一定的牺牲阳极保护作用。有机覆膜提高了锌铝涂层在海洋环境中的适用能力。     

Incorporation graphene into sprayed epoxy–polyamide coating on carbon steel: corrosion resistance properties

In this study, the graphene incorporated into epoxy–polyamide coatings were successfully obtained on carbon steel substrates by spraying process. The corrosion resistance properties of the coatings were investigated, including salt spray corrosion, sea water corrosion and electrochemical corrosion resistance. The results show that the addition of graphene could improve the corrosion resistance properties of the epoxy–polyamide coatings. The coatings in the presence of graphene had better salt spray corrosion than that in the absence of graphene. The surface of the epoxy–polyamide coating exhibited lots of pitting corrosion. The coatings with the addition of graphene showed better sea water corrosion than the coating without graphene. After drying, the epoxy–polyamide coating in the absence of graphene was broken and failed. The coating with 1?wt-% graphene exhibited the best anticorrosion capability as evidenced by the highest corrosion potential and the lowest corrosion current density. The graphene incorporated into epoxy–polyamide coatings were shown to effectively protect carbon steel against corrosion because the graphene nanosheets could be acted as the good chloride ions, oxygen and water molecules barrier.     

Studies on coatings containing nano-zinc oxide for steel protection

Zinc oxide (ZnO) nanoparticles (NPs) were synthesized using the coprecipitation method. The resulting NPs were characterized by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The surface morphology of the coatings has been characterized by scanning electron microscopy (SEM). SEM images show a uniform and homogeneous distribution of ZnO-NPs in polyurethane (PU) coatings while aggregates appear in epoxy coatings. Using tensile stress–strain test, the effect of the addition of ZnO-NPs on the mechanical properties of PU and epoxy coatings was examined. The addition of ZnO-NPs has enhanced the Young's modulus and the tensile strength of PU and epoxy coatings. Through the open-circuit potential and electrochemical impedance spectroscopy measurements, the anticorrosive properties of PU- or epoxy-coated mild steel panels containing ZnO-NPs have been investigated in 0.5 M NaCl solution. Nyquist impedance plots for PU and epoxy coatings in PU- or epoxy-coated mild steel panels containing ZnO-NPs were tested in the absence and presence of ZnO-NPs have different responses. It has been shown that the dispersion of ZnO-NPs significantly improves the anticorrosive performance of PU coatings. A PU coating containing 700 mg/kg ZnO-NPs is recommended to achieve better mechanical properties and corrosion resistance.     

Corrosion protection of aluminum alloy by epoxy coatings containing polyaniline modified graphene additives

In the study, polyaniline/reduced‐graphene oxide (PANI‐RGO) composites, fabricated by loading 2, 5, and 8wt% graphene oxide, was prepared by in‐situ emulsion polymerization and reduction. They are characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy. Epoxy coatings adding PANI and PANI‐RGO composites were coated on the surface of AA5083 Al alloy. The anticorrosion performance of the coatings is measured by electrochemical impedance spectroscopy and potentiodynamic polarization curve in 3.5wt% NaCl solution. The results demonstrate that the epoxy/PANI‐RGO coating exhibits a better protection against AA5083 alloy corrosion compared with the epoxy/PANI coating. Enhancement of the passivation performance of PANI was obtained by the addition of RGO into epoxy/PANI coating system.     

The effect of epoxy coating containing emeraldine base and hydrofluoric acid doped polyaniline on the corrosion protection of AZ91D magnesium alloy

Corrosion protection of epoxy coatings containing emeraldine base polyaniline (PANI) or hydrofluoric acid doped PANI on AZ91D magnesium alloy were studied by EIS and Pull-Off Adhesion Test. The results indicated that the addition of emeraldine base PANI or hydrofluoric acid doped PANI could improve the corrosion resistance of epoxy coating. The epoxy coating containing hydrofluoric acid doped PANI had the best performance of the corrosion protection among three systems under investigation. The corrosion product film was analyzed by XPS indicating that PANI changed the chemical structure of the corrosion film. The protective mechanism imparted by PANI was discussed.     

Effect of nanoparticles on the anticorrosion and mechanical properties of epoxy coating

Homogeneous epoxy coatings containing nanoparticles of SiO₂, Zn, Fe₂O₃ and halloysite clay were successfully synthesized on steel substrates by room-temperature curing of a fully mixed epoxy slurry diluted by acetone. The surface morphology and mechanical properties of these coatings were characterized by scanning electron microscopy and atomic force microscopy, respectively. The effect of incorporating various nanoparticles on the corrosion resistance of epoxy-coated steel was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. The electrochemical monitoring of the coated steel over 28 days of immersion in both 0.3 wt.% and 3 wt.% NaCl solutions suggested the beneficial role of nanoparticles in significantly improving the corrosion resistance of the coated steel, with the Fe₂O₃ and halloysite clay nanoparticles being the best. The SiO₂ nanoparticles were found to significantly improve the microstructure of the coating matrix and thus enhanced both the anticorrosive performance and Young's modulus of the epoxy coating. In addition to enhancing the coating barrier performance, at least another mechanism was at work to account for the role of the nanoparticles in improving the anticorrosive performance of these epoxy coatings.     

环氧纳米粉末涂层现场应用评价与缓蚀剂技术研究

目的研究一种环氧纳米粉末涂层在新疆某油田的适用性与缓蚀剂技术。方法利用高温高压釜模拟涂层在新疆某油田三种典型工况条件,结合腐蚀失重法以及结合力测试、阴极剥离、扫描电子显微电镜、交流阻抗等手段,分析环氧纳米粉末涂层腐蚀后的形态及其与基体的结合度,对其服役寿命进行预测,并研究缓蚀剂添加对未涂覆、破损和完整三种涂层状态下试样腐蚀行为的影响。结果环氧纳米粉末涂层在三种典型环境中未出现鼓泡和开裂现象,且与基体结合较好。环氧纳米粉末涂层的阴极剥离半径小于5 mm,由阴极剥离半径和阻抗值所预测的寿命分别为883d和740d。破损涂层的均匀腐蚀和点蚀速率分别为0.6172 mm/a和1.5720 mm/a,而完整涂层的腐蚀速率仅为0.0029 mm/a,破损涂层阻抗值与完整涂层的阻抗值相差103倍。微量的缓蚀剂添加可降低无涂层和破损涂层试样的腐蚀速率1个数量级,其缓蚀效率分别高达91.05%和92.75%。结论环氧纳米粉末涂层在三种典型腐蚀环境中具有好的耐蚀性能,抗剥离能力也较好,阴极剥离半径与阻抗值两种方法所预测的寿命基本一致。然而涂层一旦破损,腐蚀较为严重,尤其是点蚀,微量缓蚀剂的添加可实现不同防护技术间的优势互补。