SiAlON nanoparticles effect on the behaviour of epoxy coating

In this work, the influence of SiAlON nanoparticles loading level (0?C12?wt%) was investigated on the mechanical and chemical properties of epoxy resin-based nanocomposites coatings. The samples were characterized by fracture toughness, chemical, pull off, hardness and abrasion tests, followed by scanning electron microscopy of the fracture surfaces and sample surface after performing a chemical test. Nanoparticles were also characterized by transmission electron microscopy and linear light scattering analysis techniques. Epoxy resin coating based on bisphenol A was treated with polyamine hardener as a curing agent. Fracture toughness measurements were carried out using a single edge notched bend specimens within a three-point bending test at room temperature. Effect of SiAlON nanoparticles on the chemical resistance of epoxy resin was investigated by immersion of samples in 3.5?wt% NaCl solution at 85?°C for 60?days. Results indicated the enhancements in the mechanical properties and chemical resistance of epoxy nanocomposite due to the addition of small parts of SiAlON nanoparticles. The contents of samples with 3 and 5?wt% of SiAlON nanopowders have been considered as optimum contents compared to the other samples. They showed improvement in the crack propagation resistance in chemical solution and fracture toughness tests, both. Enhancment in abrasion resistance was found at either of 3 and 5?wt% SiAlON epoxy nanocomposite samples where they showed 59 and 34% abrasion resistance more than that of the neat resin, respectively.     

The effect of organosilane on corrosion resistance of epoxy coating containing cerium nitrate

Structure and corrosion resistance behavior of epoxy coating containing cerium nitrate in different amounts of γ-glycidoxypropyltrimethoxysilane (γ-GPS) were investigated. Corrosion resistance ability of coating systems was characterized by using electrochemical impedance spectroscopy and polarization techniques. Also atomic force microscopy was used to evaluate dispersion of cerium nitrate in the presence of γ-GPS. Furthermore, the effect of γ-GPS on flexibility of coatings was studied by using the cupping test. Increment of 10?wt.% of γ-GPS into the coating formulation led to the superior dispersion of cerium nitrate and also highest corrosion protection performance.     

Investigation of corrosion performance of epoxy coating containing polyaniline nanoparticles

An emulsion polymerization of aniline was performed in a solution of dodecylbenzenesulfonic acid emulsifier, benzoyl peroxide oxidant and tartaric acid as dopant. The polyaniline-containing coating was applied over carbon steel panels and the polyaniline content in the coating was 1?%. The influence of reactants concentration on the morphological and anti-corrosive properties of polyaniline was investigated to determine the optimum conditions for the synthesis of polyaniline nanoparticles. The average size of particles determined by X-ray diffraction measurement was 70?C104?nm, which is found to be in agreement with the scanning electron microscopy results. Corrosion resistance of coatings was obtained using electrochemical techniques (electrochemical impedance spectroscopy and open circuit potential measurements) in 3.5?% sodium chloride solution. Nyquist diagrams showed two capacitance loops, one at high frequency range followed by a larger one at low frequencies due to coating and charge transfer resistance. The corrosion resistance values were found to decrease due to the corrosion of carbon steel in pinholes of the coating. For longer immersion times, the coating resistance values were found to increase due to the passivation effect of polyaniline. The results showed that epoxy coating with doped polyaniline nanoparticles is able to offer protection in sodium chloride solution.     

环氧有机涂层对锌铁合金镀层耐蚀性的影响

利用腐蚀浸泡实验、失重法和交流阻抗谱分析等方法研究了环氧有机涂层对Q235钢电镀锌铁合金镀层耐蚀性的影响。结果表明,Q235钢基体、Q235+Zn–Fe合金镀层试样和Q235+Zn–Fe合金镀层+环氧有机涂层试样在5%NaCl溶液中浸泡504 h后,腐蚀速率分别为0.068 0、0.040 0和0.018 0 mm/a。涂覆环氧有机涂层至少能使锌铁合金镀层的防腐性能提高2倍,从而延长基体材料的使用寿命。     

环氧／纳米ZnO复合涂层对镁锂合金耐腐蚀性的影响

以聚丙烯酰胺凝胶法制备了纳米ZnO,并对其进行改性,得到了环氧/纳米ZnO复合涂层.采用XRD和SEM对环氧/纳米ZnO复合涂层进行了表征.通过极化曲线和交流阻抗研究了裸基、复合涂层以及经锡酸盐转化处理后涂覆环氧/纳米ZnO的复合涂层的耐蚀性能.结果表明:复合涂层呈明显的两相结构,纳米ZnO分布均匀;复合涂层和锡酸盐转化协同,提高了镁锂合金的耐腐蚀性能.涂层中纳米ZnO质量分数不同,对镁锂合金耐蚀性能有不同的影响,纳米ZnO质量分数为2%时,复合涂层对镁锂合金的保护作用最强.     

The effect of mixture of mercaptobenzimidazole and zinc phosphate on the corrosion protection of epoxy/polyamide coating

The protective performance of solvent-borne epoxy/polyamide coatings formulated with zinc phosphate anticorrosion pigment was improved through the addition of 2-mercaptobenzimidazole as an organic corrosion inhibitor. In addition to determining the optimum percentage of mercaptobenzimidazole, the electrochemical impedance spectroscopy data could show the influence of inhibitor concentration on the epoxy behavior within 35 days of immersion in 3.5 wt% NaCl solution. The improved corrosion protection and adhesion strength in the presence of the pigment and inhibitor were connected to the deposition of a protective layer at the coating/substrate interface which might limit active zones for electrochemical reactions. The precipitation was confirmed using electrochemical impedance spectroscopy, polarization curves and SEM/EDX surface analysis.     

Tribological properties and corrosion resistance of epoxy resin-polytetrafluoroethylene bonded solid lubricating coating filled with flake aluminum

The aims of this work are to prepare a novel epoxy resin-polytetrafluoroethylene (expressed as EP/PTFE) bonded solid lubricating coating filled with flake aluminum. The focus is to study the effects of two different flake aluminum (floating type and non-floating type) on the tribological performance and anti-corrosion capability of the coating. A CSM friction tester was applied to evaluate the tribological performance of the coating. The electrochemical technique was applied to study the corrosion resistance of the coating. And the experimental results showed that both types of flake aluminum can ameliorate the tribological performance and anti-corrosion properties of the EP/PTFE lubricating coating. Moreover, compared with floating flake aluminum, the incorporation of non-floating flake aluminum significantly improved the tribological properties and corrosion resistance of the EP/PTFE coating due to its good dispersibility, greater enhancement effect on mechanical performance and stronger barrier properties.     

装饰用铜合金镧-铈复合化学转化工艺及膜层耐蚀性

对装饰用H62铜合金进行稀土镧-铈复合化学转化.对转化液组成和工艺条件进行正交优化,得到最优参数为:硝酸镧4 g/L,硝酸铈4 g/L,苯并三氮唑15 g/L,钼酸钠2 g/L,柠檬酸13 g/L,磺基水杨酸9 g/L,十二烷基苯磺酸钠0.4 g/L,温度53°C,时间4 min.该条件下所得La-Ce复合转化膜的厚度...     

Evaluation of the effect of vinyltrimethoxysilane on corrosion resistance and adhesion strength of epoxy coated AA1050

The quality of surface treatment of aluminum alloy (AA1050) with vinyltrimethoxysilane (VTMS) was examined. Calculated surface energy with Van Oss, Chaudury and Good (VOCG) method showed higher surface energy of treated specimens. Chemical interaction between silane layer and aluminium surface was examined via FTIR-ATR. In addition, practical adhesion was measured in dry, wet and recovered states via pull-off method and compared to adhesion strength of desmutted and chromated specimens. Results showed good adhesion performance in dry state for silane treated specimens. Corrosion protective performance of epoxy coating in the presence of silane layer on aluminum was studied with Electrochemical Impedance Spectroscopy (EIS) and compared with coated desmutted and chromated specimens. Water sensitivity of silane layer resulted in poor protective performance of specimens treated at pH > isoelectric point (IEP).     

热浸镀锌层氟钛酸转化膜的制备和耐蚀性能

以氟钛酸为成膜剂、磷酸二氢锰为促进剂对热浸镀锌层表面进行钝化处理,获得了氟钛酸转化膜。采用扫描电镜研究了不同处理时间所得转化膜的微观形貌;通过中性盐雾试验、电化学极化和电化学阻抗谱,研究了不同处理时间所得转化膜的耐蚀性。确定了氟钛酸转化膜的制备工艺条件为:H2TiF6(w=60%)5mL/L,Mn(H2PO4)2·2H2O15g/L,pH2.5,处理时间1min。与未经处理的热浸镀锌试样相比,经氟钛酸钝化后的试样在中性盐雾试验中出现白锈的时间明显延迟,在5%NaCl溶液中的腐蚀电流密度明显降低,极化电阻和电化学阻抗显著增大。处理时间为1min时所得转化膜的耐蚀性能最好。     

三种环氧胶粘剂耐蚀性能研究

通过改变固化剂的种类(T-31和PA)、填料的种类(粉煤灰和纳米蒙脱土)配制了三种环氧胶粘剂,并通过不同的腐蚀介质来研究其耐蚀性能。实验采用的浸泡介质为机油、水、10%HCl水溶液、10%NaOH水溶液、3%NaCl水溶液。环氧胶粘剂的耐蚀性能是通过测定其拉伸剪切强度来评定的。推荐了三种胶粘剂适宜服役的腐蚀环境,为其在粘接领域的应用提供基础数据。     

无铬达克罗涂料工艺及耐蚀性能研究

以稀土铈盐为添加剂,用磷酸钝化膜替代铬酐进行无铬达克罗涂料的工艺和性能研究。结果表明,锌铝(质量比为4∶1)290～320 g/L、磷酸80～90 g/L,铈盐1.5～2.0 g/L的配方涂料,在80℃下预烘15 min,然后280℃固化30 min后,可得到优良耐蚀性能的无铬达克罗涂层;电化学法研究显示,铈盐的添加有效降低了涂层的腐蚀电流。     

Preparation and anticorrosion resistance of a self-curing epoxy nanocomposite coating based on mesoporous silica nanoparticles loaded with perfluorooctyl triethoxysilane

Organic coatings are prone to failure due to diffusion of the corrosion media toward the metal surface through the microcracks caused by internal and environmental stresses especially in immersion environment. In order to extend the service lifetime of organic coatings, we developed a self-curing epoxy resin/perfluorooctyl triethoxysilane (POTS)-loaded mesoporous silica nanoparticles (MSNs) nanocomposite (SEP/POTS-MSNs) coating, by embedding the POTS-loaded MSNs (POTS-MSNs) into an SEP resin. Fourier transform infrared, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analyses were conducted to confirm the successful loading of POTS in the MSNs. Thermogravimetric analysis was used to characterize the loading amount of POTS. The corrosion protection properties of the SEP, SEP/MSNs, and SEP/POTS-MSNs coatings were evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization tests. The results indicate that the SEP/POTS-MSNs coating with only 30 μm thickness showed corrosion resistance with Z _{f = 0.01 Hz} of 4.7 × 10⁸ Ω/cm² and i_corr of 0.026 nA/cm² after 58 hr of immersion in boiling water, which were both two orders of magnitude higher than those of the SEP coating. The SEP/POTS-MSNs coating combines the advantages of the SEP coating and the POTS-MSNs. We anticipate that the SEP/POTS-MSNs coating has promising potential for use in immersion environments.     

环氧树脂／纳米蒙脱土胶粘剂耐蚀及耐磨性研究

通过正交试验研究了环氧树脂、固化剂、增韧剂、有机化纳米蒙脱土、偶联剂对环氧胶粘剂拉伸剪切强度的影响,并对所得配方的胶粘剂进行腐蚀和冲蚀磨损试验,由此推荐环氧树脂／纳米蒙脱土胶粘剂各组分的最佳加入量。     

环氧树脂纳米蒙脱土胶粘剂耐蚀性能研究

研究了水泥、蒙脱土(有机化和未有机化)和粉煤灰作为填料在环氧树脂胶粘剂涂层中的作用,讨论了不同填料对胶粘剂的耐蚀性能的影响。试验采用的腐蚀介质有自来水、氢氧化钠水溶液、氯化钠水溶液和盐酸溶液。试验结果表明加入有机化蒙脱土的环氧树脂胶粘剂,在无介质,强酸和强碱环境中,都具有较好的拉伸剪切强度。推荐了在不同介质条件下的胶粘剂的使用配方。     

基于木质纤维素纳米纤维的自愈合涂层的制备及耐蚀性

将载体木质纤维素纳米纤维(CNF)与缓蚀剂聚天冬氨酸(PASP)以一定比例加入环氧树脂中制得改性环氧树脂,并分别将普通环氧树脂、改性环氧树脂、普通环氧树脂逐层涂覆于Q235碳钢表面制得微脉状管网型自愈合涂层.用刀片对涂层进行划痕处理后,浸泡在3.5％NaCl溶液中进行电化学测试,并结合扫描电子显微镜观察,研究了涂层的自...     

环氧地坪涂料在酸碱环境中的应用

用低黏度环氧树脂、活性稀释剂、固化剂、流平剂、消泡剂、不同目数的硅微粉等配制的地坪涂料,经实际使用,效果良好。环氧地坪涂料固化物经43%硫酸溶液60℃/120 h及5.3%次氯酸钠溶液常温/200 h浸泡,质量变化率均小于1.2%。