二维材料改性水性聚氨酯防腐涂料的研究进展

水性聚氨酯涂料作为一种新兴的环保涂料,在防腐领域得到了广泛应用。然而,水性聚氨酯涂料交联密度低,耐水性稍差,不利于其长效防腐性能。利用具有独特物理化学特性的二维材料作为水性聚氨酯的填料,可以有效改善其性能。本文主要介绍了三种二维材料(石墨烯、MXene和六方氮化硼)作为填料与水性聚氨酯进行复合,并重点介绍了石墨烯、MXene和六方氮化硼的改性方法,并对水性聚氨酯复合涂层的性能进行了阐述和比较,最后对未来二维材料/水性聚氨酯的复合材料的发展和应用进行了展望。     

阳极氧化法制备光电化学防腐蚀二氧化钛薄膜

应用阳极氧化法制备二氧化钛薄膜.研究了阳极氧化电压、电解质的性质、浓度对二氧化钛薄膜光电化学防腐蚀性能的影响,并测定该薄膜在模拟海水中的极化曲线以及与45#碳钢的耦合电流曲线.     

Spectroscopic studies of triethoxysilane sol-gel and coating process

Silica sol-gels have been prepared under different conditions using triethoxysilane (TES) as precursor. The prepared sol-gels have been used to coat aluminum for corrosion protection. Vibrational assignments have been made for most vibration bands of TES, TES sol-gel, TES sol-gel-coated aluminum and xerogel. It has been noticed that air moisture may have helped the hydrolysis of the thin coating films. Xerogels have been obtained from the sol-gel under different temperature conditions and the resulting samples have been characterized by using infrared and Raman spectroscopic methods. IR data indicate that the sol-gel process is incomplete under the ambient conditions although an aqueous condition can have slightly improved the process. Two nonequivalent silicon atoms have been identified from the collected (29)Si NMR spectra for the sol-gel, supporting the result derived from the IR data. The frequency of SiH bending vibration has been found to be more sensitive to the skeletal structure than that of the SiH stretching vibration. A higher temperature condition could favor the progression of hydrolysis and condensation. A temperature higher than 300 degrees C would cause sample decomposition without seriously damaging the silica network. From infrared intensity measurements and thermo-gravimetric analyses, the fractions of incomplete hydrolysis and condensation species have been estimated to be 4% and 3%, respectively. Electrochemical data have shown that the sol-gel coating significantly improves the corrosion protection properties of aluminum.     

大分子植酸-聚有机硅倍半氧烷的合成及性能

采用溶胶-凝胶方法, 无需小分子酸催化剂, 利用硅烷化植酸的反应活性和酸催化活性, 与硅烷单体共水解缩聚, 在聚有机硅倍半氧烷分子链上原位接枝植酸, 合成了分子量大于50000的大分子植酸-聚有机硅倍半氧烷. 用GPC, 13C NMR, 29Si NMR, XPS, Raman光谱, SEM及电化学测试等分析手段进行表征, 对比不同酸催化植酸-聚有机硅倍半氧烷(PAP), 单宁酸-聚有机硅半氧烷(TAP), 盐酸-聚有机硅半氧烷(HCP)的结构和性能, 发现植酸-聚有机硅倍半氧烷上的螯合基团与金属表面的活性基团反应而键合, 在金属表面形成致密的保护膜, PAP与TAP和HCP比较具有优异的防腐性能.     

The role of 1-octyl-3-methylimidazolium hexafluorophosphate in anticorrosion coating formula development

A hydrophobic ionic liquid (1-octyl-3-methylimidazolium hexafluorophosphate, C₈mimPF₆) with a function of inhibiting corrosion was encapsulated at different concentrations in the copolymer of poly (methyl methacrylate) and poly (butyl acrylate) through miniemulsion polymerization. These latexes were coated on steel samples whose corrosion properties were evaluated by electrochemical techniques. It was found that increasing the C₈mimPF₆ concentration from 0 wt% to 30 wt%, the corrosion inhibition efficiency was remarkably improved from 41% to 89% based on the charge transfer resistance and from 64% to 87% based on the corrosion current density, respectively. The ionic liquid did not attend the reaction during latex preparation but behaved as corrosion inhibitors on the steel surface. Such an anticorrosion effect could be ascribed to the physical adsorption of the C₈mim⁺ cation on the reaction sites and the hydrophobicity enhancement resulting from the hydrophobic PF₆^? anion.     

Modification of nano-hybrid silicon acrylic resin with anticorrosion and hydrophobic properties

Silicone-acrylic resin (SAR) was prepared from acrylic monomers and silicone prepolymer by the free radical solution polymerization, and then mixed TiO₂ and SiO₂ nanoparticles modified by KH570 were added to prepare nanocomposite coating. Thermogravimetric analysis and contact angle measurements showed that the acrylic resin modified by silicone prepolymer exhibited an improved thermostability and a better hydrophobicity compared with the unmodified sample. The adding of nanoparticles further increased the hydrophobicity. The contact angle of modified silicone-acrylic resin with mixed TiO₂ and SiO₂ nanoparticles of 3 wt% is the highest, 108.4°. The UV resistance and weather resistance of the modified silicone-acrylic resin are significantly improved. It was also found through electrochemical impedance spectroscopy that the corrosion resistance was significantly improved by the addition of mixed TiO₂ and SiO₂ nanoparticles. Modified silicone-acrylic resin with mixed TiO₂ and SiO₂ nanoparticles of 3 wt% and 5 wt% coating system maintains an excellent anticorrosion performance (coating resistance R_c of more than 10⁹ Ω cm²) even at 3.5% NaCl electrolyte medium till to 1800 h.     

聚苯胺的表面修饰及防腐性能

用八甲基环四硅氧烷(D₄)对聚苯胺(PANI)进行表面修饰, 通过对产物的循环伏安(CV)、 极化曲线(Tafel)以及接枝率的表征分析, 考察了反应温度、 反应时间、 单体用量和pH值对产物的接枝效果、 分散性和腐蚀电位的影响. 同时, 通过循环伏安(CV)、 紫外-可见光谱(UV-Vis)、 红外光谱(FTIR)、 X射线衍射分析(XRD)和热重分析(TGA), 对PANI表面修饰前后的结构和性能进行了比较. 结果表明, 通过D₄对PANI颗粒表面进行修饰, PANI的分散性、 分散稳定性和和防腐能力得到显著提高.     

Enhancement corrosion resistance of (3-methacryloxypropyl)silsesquioxane hybrid films and its validation by gas-molecule diffusion coefficients using MD simulation

In the first part of this work, based on silsesquioxanes (SSO) derived from hydrolytic condensation of (3-methacryloxypropyl)trimethoxysilane (MPMS) and tetraethoxysilane (TEOS), two hybrid films, f-MPMS-SSO (f-MS) and f-MPMS-TEOS-SSO (f-MTS) modified with 15 wt% TEOS, were prepared. The anticorrosion properties (corrosion potential, E _corr, and corrosion current density, I _corr) of the bare aluminum alloy (AA) and the two films on AA were tested by electrochemical measurements with typical potentiodynamic polarization curves. The I _corr values of three samples are significantly different with the order of f-MTS < f-MS < AA which implies that the TEOS addition in the f-MTS coating indeed enhances the electrochemical corrosion resistance. Correlations between the structures of two films and anticorrosion properties were discussed. In the second part of this work, two different 3D-amorphous cubic unit cells, cell(f-MS) and cell(f-MTS), as models were employed to investigate self-diffusion coefficients by molecular dynamics (MD) simulation for the NO₂, SO₂ and H₂O molecules. All three self-diffusion coefficients of NO₂, SO₂ and H₂O diffusing in cell(f-MTS) were less than the coefficients in cell(f-MS), which validates the corresponding anticorrosion-experiment results. Two reasons why the addition of TEOS in the system of f-MTS leads to a lowering of the gas self-diffusion coefficient compared to the f-MS system, were discussed. An erratum to this article can be found at     

Synthesis and Electrochemical Properties of a Novel Poly(ether sulfone) with Oligoaniline Pendants

A novel poly(ether sulfone) with oligoaniline pendants(PESOP) was prepared by K₂CO₃-mediated nucleophilic polycondensation and characterized with Fourier-transform infrared spectrometry(FTIR), ¹H nuclear magnetic resonance(¹H NMR) and gel permeation chromatography(GPC). The cyclic voltammetry(CV) curve of PESOP reveals the reversible electroactivity. In the electrochromism study, PESOP film exhibited good electrochromic properties with a high contrast value, moderate switching time and acceptable coloration efficiency. After running 1000 cycles, the PESOP/indium-tin oxide(ITO) electrochromic device remained unchanged except for the drifting of base line, which certified its good electro-photo stability of the fabricated electrochromic device. Moreover, the polarization technique and electrochemical impedance spectroscopy(EIS) were used to study the anticorrosion performance of PESOP coatings on the cold rolled steel(CRS) in a 5%(mass fraction) NaCl solution. All the results indicate that the obtained PESOP is a competitive candidate as anticorrosion material.     

3-氨基-1,2,4-三氮唑自组装膜对黄铜的缓蚀作用

3-氨基-1,2,4-三氮唑(ATA)是一种环境友好型金属处理剂, 以其在黄铜表面制备了自组装单分子膜(SAMs), 用电化学方法研究ATA SAMs对黄铜的缓蚀作用及其吸附行为. 结果表明, ATA分子易在黄铜表面形成稳定的ATA SAMs, SAMs抑制了黄铜的阳极氧化过程, 改变了电极表面的双电层结构, 固/液界面双电层电容明显降低, 有良好的缓蚀效果. 研究结果还表明, ATA的吸附行为符合Langmuir吸附等温式, 吸附机理是典型的化学吸附.