P/B对水性聚氨酯防腐蚀涂料性能影响研究

以水性聚氨酯为基料,加入颜填料和助剂合成水性防腐蚀涂料。改变涂料配方中颜填料和基料的质量比(P/B),在不锈钢板上制得涂层样品,通过极化曲线和电化学阻抗测试,讨论P/B对涂层腐蚀性能的影响,试验结果表明,涂料配方中P/B=0.8和1.5时涂层综合性能较好。     

聚苯胺微乳液及其对水性防腐涂料防腐性能的影响

目的用不同酸掺杂的聚苯胺微乳液制备水性防腐涂料,提高马口铁表面涂层的耐腐蚀性能。方法采用扫描电子显微镜、傅立叶变换红外光谱和热重分析表征聚苯胺性能,通过动电位极化法及耐水性、耐盐雾和耐盐水实验检测聚苯胺微乳液水性防腐涂层的防腐性能,用铅笔硬度和划格法表征涂层的硬度和附着力。结果磷酸掺杂聚苯胺微乳液、本征态聚苯胺微乳液制备的水性防腐涂层都对马口铁起到良好保护作用。含有盐酸掺杂聚苯胺微乳液和不含聚苯胺微乳液的水性防腐涂层在浸泡过程中很快失去保护作用。掺杂态聚苯胺使马口铁表面钝化和屏蔽,本征态聚苯胺起机械屏蔽作用。通过把聚苯胺微乳液添加到水性防腐涂料中,发现涂层的硬度和附着力均没有发生明显下降,表明聚苯胺微乳液在水性防腐涂料中分散均匀,对涂层的性能影响较小。结论当水性防腐涂料中的聚苯胺质量分数为0.3%时,磷酸掺杂的聚苯胺微乳液具有最佳的耐腐蚀性能,其腐蚀电流密度Jcorr=7.359×10-7 A/cm2,腐蚀电位Ecorr=-0.527 V。     

Protective Metal Coatings—a Review

Abstract

Metal coatings are used to combine corrosion resistance with other properties peculiarto the metal, and are not interchangeable to the extent of paints, for example. The decorative nickel plus chromium systems are omitted from this report, having being covered by Arrowsmith in 1966 and 1968.     

Effect of nano-Fe2O3 particles on the corrosion behavior of alkyd based waterborne coatings

A nano-composite coating was formed by adding nano-Fe₂O₃ to a specially developed alkyd based waterborne coating system. The interaction of nano-particles with the polymer functionalities was confirmed using FTIR. Curing behavior of the coating was determined by DSC. The uniformity of coating and dispersion of nano-particles in the polymer matrix was investigated using SEM and AFM. The performance of the coating was investigated in terms of their corrosion resistance, UV-resistance, mechanical properties and optical properties. Composite coatings so formed showed enhanced, corrosion resistance, better mechanical properties such as abrasion and scratch hardness and improved UV blocking properties.     

石化行业用金属防腐涂料现状及发展

介绍了石化厂内金属设施所用到的各种涂料，如油罐、平台和楼梯、管道、换热器内壁以及用量较少的几种特种涂料，对其优缺点进行评介，指出具有发展前景的品种.最后，提出以水性涂料      

Influence of heat treatment on surface morphology,hardness, wear and corrosion resistance of industrial phosphate coatings

Abstract

New phosphate black coatings for the improvement of mechanical properties on metallic objects have been developed to extend life time of machinery. The performance of phosphate black coatings was evaluated by weight gain studies, micro hardness studies, abrasive wear resistance and corrosion resistant measurement by electrochemical methods. The surface morphology of the coatings was assessed by XRD, SEM and XPS. The absorption coefficient of the coatings was evaluated by UV-visible spectrometer. Salt spray analysis was carried out to follow up the corrosion and get an idea about the performance of black coatings in automobile parts. The mechanical properties were very much improved after heat treatment of coatings at 200°C.     

Research into the Properties of Materials for Underwater Structures in the North Sea

Constructing under water has accelerated research into corrosion protection and antifouling properties of materials used below the seawater level. A special working party was founded in the Netherlands to study — theoretically and practically — the corrosion and fouling properties of materials and coatings. A special test rack was immersed at a depth of 50 m in the North Sea in 1969. Experience gained from these experiments gave rise to a joint investigation by 13 laboratories in the Netherlands; the programme involves ten test racks 50 and 100 m below sea level, in the tidal zone and in marine and land atmospheres. The materials studied were: steel with various paints and coatings; stainless steel, Cu, Al and Ti alloys; welded, brazed, nailed and glued stainless steel, Al and Ti alloys; synthetic fibers. The test methods included crevice corrosion and stress corrosion bending tests, electrochemical measurements and the regular control of the biological conditions. The results show the importance of testing in specific marine areas because the results are not readily applicable to conditions in other geographical regions.     

Electrochemical corrosion behaviour and surface morphology of electrodeposited zinc,zinc–cobalt and their composite coatings

Abstract

The electrochemical behaviour as well as the surface morphology characteristics of electrodeposited Zn and Zn-Co (≈3 wt-%) alloy coatings on low carbon steel samples, with and without included nanoparticles of organic co-polymers in their structure, are discussed. Their corrosion resistance and protective properties were studied in a model corrosion medium, 5 wt-% NaCl, using electrochemical methods such as polarisation resistance (R _p) measurements and potentiodynamic (PD) polarisation curves. Scanning electron microscopy (SEM) was performed to examine the surface morphology changes of the samples before and after the corrosion treatment. Some conclusions are drawn about the influence and importance of the organic nanoparticles on the corrosion behaviour of the coatings presented.     

Influence of SiC + WC addition to Cr(VI) bath on corrosion behaviour of coatings in sulphate solution

Abstract

Cr–WC–SiC coatings were deposited from Cr(VI) baths containing a mixture of both WC and SiC particles in the ratio of 1 : 1. X-ray photoelectron spectroscopy data indicated relatively low percentages of both WC (about 2˙68–2˙85 at.-% of W4f) and SiC (0˙16–0˙45 at.-% of Si2p) particles in the top layers of the Cr–WC–SiC coatings. However, these particles have some effect on the morphology and corrosion properties of the Cr coating. Protective properties of the coatings obtained were studied at different exposure times of samples in sulphate solution (pH=2˙8), using the electrochemical impedance spectroscopy method (EIS). Equivalent circuits, based on the electrophysical model describing the electrochemical corrosion at the coated surface, were proposed. The simulation of EIS data with the proposed equivalent circuit models made it possible to reveal the details of the corrosion processes occurring at coated systems (steel/Cr–WC–SiC coatings) immersed in the sulphate solution. Based on EIS data, diffusion in the coating was found to be a significantly controlling factor in the corrosion process for the system under investigation. The electrochemical impedance spectroscopy tests indicated a better corrosion resistance of Cr–WC–SiC coating than that of Cr. Analysis of the EIS data suggests that the enhanced corrosion resistance of Cr–WC–SiC coating was due to the microstructural features of these coatings, presumably containing smaller pores than Cr coating.     

Organic corrosion inhibitors for zinc pigment

Abstract

A severe problem with waterborne paints containing zinc pigments is hydrogen corrosion of the zinc in the aqueous alkaline paint media. The subject of the present study is the examination of corrosion inhibition of the zinc pigment in aqueous alkaline media by different high and low molecular weight organic inhibitors compared with that given by potassium dichromate. Potassium dichromate inhibits this corrosion reaction moderately, but a 4·0 mmol addition in 100 mL of the corrodent (1·2 wt-%) is required. Heterocyclic compounds are very poor corrosion inhibitors and less effective than potassium dichromate. Certain polymers with low acid numbers and low molecular weights and one particular epoxy ester resin are more effective inhibitors than potassium dichromate. Thus, some non-toxic polymers or paint resins can be considered as possible substitutes for toxic potassium dichromate.