聚苯胺的腐蚀防护机理及其在金属防腐中的应用之我见

聚苯胺是一种新型的化学防护材料,能够起到防治金属被腐蚀的作用,因其良好的防护性能,近年来被广大材料工作者广泛研究,也取得了一定的成果。本文简单介绍聚苯胺对金属腐蚀的防护机理,并据此谈一点关于其在金属防腐工作中的应用,供广大同仁参考。     

聚苯胺及其衍生物在防腐领域中的应用进展

概述了聚苯胺的结构、性质及其防腐机理。聚苯胺主要通过其屏蔽作用在金属表面促进形成钝化层和提高金属氧化电位,降低金属材料的腐蚀速度。因此,聚苯胺经常被用做缓蚀剂、聚苯胺防腐涂层和防腐涂层的添加剂。相较于缓蚀剂与聚苯胺涂层,聚苯胺复合涂层具有优异的防腐性能。综述了近年来聚苯胺及其衍生物在防腐领域的进展,提出了聚苯胺在防腐应用中需进一步解决的问题。     

水溶性聚苯胺合成及聚苯胺在防腐领域的应用

介绍了聚苯胺的结构,主要讨论了水溶性聚苯胺的3种合成方法,及聚苯胺在防腐领域的研究及发展,阐述了聚苯胺的防腐机理和聚苯胺防腐涂层的应用,并对其前景进行展望,认为水溶性聚苯胺的合成研究及其缓蚀理论分析还需进一步深入地开展研究。     

聚苯胺在金属腐蚀保护中的应用

综述了聚苯胺用作金属腐蚀涂层和缓刨剂的研究状况,讨论了聚苯胺的防腐机理。     

导电聚苯胺的制备及其在防腐涂料中的应用

介绍了导电聚苯胺的结构、性能特点,概述了制备聚苯胺的常用方法：化学氧化聚合法和电化学法,并介绍了导电聚苯胺的防腐机理及其在防腐涂料中的应用研究进展。     

新型导电高分子材料聚苯胺的合成及应用

聚苯胺是近年来导电高分子领域的研究热点之一。本文概述了聚苯胺的几种主要合成方法及应用研究。     

聚苯胺在防腐涂层中应用研究进展

聚苯胺被认为是最有应用前景的导电聚合物,目前被广泛应用在涂料、传感器、电极及电磁屏蔽等领域,而其在防腐涂层中的应用是目前研究的热点。综述了聚苯胺纳米结构的制备及其在防腐涂层中的应用,并归类总结了目前对聚苯胺防腐机理的推测与研究进展。     

聚苯胺的合成及应用研究进展

聚苯胺是研究最为广泛的导电高分子材料之一。综述了聚苯胺的各种合成方法,介绍了聚苯胺的应用前景。     

导电聚苯胺在电流变液中的应用

简述了电流变液的研究现状,着重介绍了含聚苯胺粒子电流变液的应用现状及发展前景。     

水溶性导电聚苯胺的制备及应用研究进展

水溶性导电聚苯胺由于其优异的电性能和化学稳定性,具有潜在的实用性价值.总结了水溶性导电聚苯胺的制备方法,重点阐述了聚苯胺衍生物和共聚态聚苯胺的制备,提出了水溶性导电聚苯胺的发展方向.     

Synthesis and properties of oxalic acid-doped polyaniline

Conductive polyaniline was synthesized in aqueous 1.0M oxalic acid containing 0.1 M aniline by electrochemical and chemical oxidation and characterized by conductivity, solubility, ultraviolet and infrared spectroscopy, and cyclic voltammetry. The solubility experiments showed that the solubility of oxalic acid-doped polyaniline in dimethylsulfoxide and dimethylformaide increased to a certain extent. The soluble part of the polyaniline was free from impurities such as quinones. Cyclic voltammetric studies in oxalic acid medium revealed that aniline exhibited a similar behaviour to that in H₂SO₄ and the polymerization rate was much slower than that in H₂SO₄.     

Undoped polyaniline–surfactant complex for corrosion prevention

Due to the strict regulations on the usage of heavy metals as the additives in the coating industries, the search for effective organic corrosion inhibitors in replacement of metal additives has become essential. Electrically conducting polymers have been shown to be effective for corrosion prevention, but the poor solubility of these intractable polymers has been a problem. We have explored a polyaniline–4-dodecylphenol complex (PANi–DDPh) to improve the dissolution, and it has been shown to be an effective organic corrosion inhibitor. With the surfactant, DDPh, PANi could be diluted into the coatings, and the properties of the coatings were affected. An emeraldine base (EB) form of PANi was also found to be oxidized by the hardener. The oxidized form of polyaniline provides improved corrosion protection of metals than that of emeraldine base since the value of the standard electrode potential for the oxidized form of PANi is higher than that of EB. Additionally, the surfactant improves the wet adhesion property between the coating and the metal surface. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2849–2856, 1999     

Composites based on poly(ethylene terephthalate) fibers with polyaniline. II. The effect of the growth of the polyaniline molecules during the polymerization in the morphology of the PET substrate

PET fibers of different drawn ratios were used as substrates to produce composites with PANi. The influence of the growth of the polyaniline molecules in the structure of the fibers previously pretreated in the presence of aniline at different conditions were studied by different characterization techniques (differential scanning calorimetry, X‐ray scattering, dynamic and mechanical thermal analysis, sonic modulus, and scanning electron microscopy). The polymerization of the aniline inside the fiber substrates modified the structure of the fibers. In the case of the drawn fiber substrates the growth of the PANi molecules occurred mainly in the interfibrillar regions, which promoted reorganization of the preexisting crystals such as defect elimination (mainly in the interface of these regions with the lamellar regions) and at same time reorientation of their amorphous and crystalline regions. Also, due to this reorientation process the crystals became not only bigger and more perfect, but also they became more homogeneous. In the case of the undrawn fiber substrates, due to the lack of previous orientation, the growth of the PANi molecules would be occurring in the amorphous interlamellar regions only. Finally, the use of fibers with different drawn ratios as substrates for the composites was essential to reach such conclusions. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2346–2362, 2000     

Protection of stainless steel by polyaniline films against corrosion in aqueous environments

Polyaniline (PANI) thin films were electrochemically deposited by cyclic voltammetry on stainless steel electrode previously covered by a thin film of polyvinyl acetate (PVAc). The corrosion resistance of PANI covered stainless steel substrates was estimated by using potentiodynamic polarization curves and its linear polarization resistance (LPR) was measured in 0.5 M H₂SO₄, 0.5 M NaCl and 0.5 M NaOH aqueous solutions at room temperature. The results indicate that the PANI-PVAc films did improve the corrosion resistance of the stainless steel in NaOH, behaving even worst, in the case of PANI film, than the uncoated substrate. In H₂SO₄ both PANI and PANI-PVAc coatings gave good protection for the stainless steel electrode, with a slightly better performance of PANI-PVAc than PANI. In NaCl solution both PANI and PANI-PVAc films provided a good protection against corrosion. The better performance of PANI-PVAc coatings for corrosion protection in basic media may be due to its major chemical stability compared to simple PANI films, which lose their conductivity in high pH solutions. The E _corr (free corrosion potential) value of the coated substrate was in the passive region of the uncoated substrate in acidic environment but in the active region in neutral or basic environment.     

Effects of polyaniline content in chlorrub‐based coatings on corrosion protection of steel

Corrosion protection of steel coated with chlorrub resin containing polyaniline has been studied in 3% NaCl by electrochemical impedance spectroscopy (EIS). Polyaniline was prepared by oxidative polymerization of aniline using ammonium persulphate in HCl medium. Using the synthesized polyaniline, paints were prepared using chlorrub resin with 1, 3, and 5% polyaniline. The variation of resistance and capacitance of the coating with time has been found out be EIS. The study has shown that the polyaniline content of 1% is able to offer sufficient protection of steel in neutral media and usage of higher percentage of polyaniline does not have beneficial effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3994–3999, 2006     

聚苯胺颗粒对水性环氧树脂涂层防腐性能的影响

以盐酸为掺杂剂、过硫酸铵为氧化剂、咪唑类离子液体为稳定剂,采用化学氧化聚合法合成了导电聚苯胺(PANI)颗粒,将其分散到水性环氧树脂(ER)中制成聚苯胺水性环氧防腐涂层,研究了聚苯胺颗粒对涂层防腐性能和机械性能的影响。结果表明,添加聚苯胺显著提高了水性环氧涂层的阻隔性能,信号频率f=0.01 Hz时,PANI/ER涂层的阻抗(|Z|f=0.01Hz)均高于纯ER涂层。添加5.0wt% PANI时ER涂层阻隔性能最好,浸泡0~168 h时|Z|f=0.01Hz稳定在约8.0×108 Ω?cm2,浸泡168 h后|Z|f=0.01Hz=7.5×108 Ω?cm2,远高于ER和其它PANI/ER体系。中性盐雾实验结果表明,聚苯胺赋予了涂层钝化腐蚀的能力,显著提高了涂层的防腐性能,且其添加量越高,防腐性能越好。弯曲和冲击实验结果表明,涂层的机械性能随聚苯胺含量增加先上升后降低,当聚苯胺添加量不超过5.0wt%时,涂层的机械性能优异,附着力和韧性均较好;PANI添加量增至7.0wt%时,ER涂层的脆性明显变大,机械性能下降。聚苯胺在水性环氧体系中的最宜添加量为5.0wt%,此时涂层的机械性能良好,综合防腐性能最优。     

金属材料防腐技术的研究进展

综述了国内外金属防腐技术的研究现状,分别介绍了缓蚀剂、金属镀层以及金属涂层防腐技术的研究进展,并展望了金属防腐理论与技术的发展趋势。     

车用甲醇燃料金属腐蚀抑制剂的研究

通过分析甲醇燃料对金属部件的腐蚀原理,提出了抑制腐蚀的措施,以及通过气相色谱-质谱联用仪器、电化学工作站和金属腐蚀仪三种实验方法,分析了几种典型物质的缓释效果,从而得出甲醇燃料腐蚀抑制剂的主要组分。