锌锰干电池两种代汞缓蚀剂

通过浸泡实验,极化测量考察了在26％NH_4Cl溶液中BiCl_3、有机复合物MA对锌的缓蚀性能,并与HgCl_2的情况进行了对比。结果表明铋类似于汞同为阴极型缓蚀剂,但其适用的浓度范围较窄,在有氧存在时失去缓蚀作用。MA则为阳极型缓蚀剂,有较宽的浓度适用范围,在有氧存在的条件下,仍表现较好的缓蚀作用。     

锌电极电化学行为研究(Ⅴ)——有机缓蚀剂对碱液中无汞锌膏电极充放电的影响

利用电化学阻抗技术及循环伏安法,对碱性电液中无汞锌膏电极的电化学行为进行了研究,并讨论了一些有机缓蚀剂对静置、充电和放电状态下的无汞锌膏电极的阻抗行为及循环伏安行为的影响及缓蚀机理。     

火电厂循环冷却水系统防腐技术试验与应用

针对火力发电厂循环冷却水系统溶解氧腐蚀、冲刷腐蚀及电化学腐蚀进行了分析,通过添加特效缓蚀剂使金属表面形成牢固、均匀、致密的保护膜层,使金属同循环水介质隔离而起到保护。达到了“GB50050—95”标准中铜及铜合金腐蚀速率宜小于0.005m/a的要求,现场应用效果良好。     

NaNO3对含Cl^—衣康酸溶液中316L不锈钢的缓蚀作用

通过失重法和电化学法以及表面膜ＸＰＳ分析，研究了ＮａＮＯ３对含Ｃｌ＾－衣康酸介质中３１６Ｌ不锈钢的缓蚀性能，结果表明：溶液中一定量的ＮａＮＯ３可使不锈钢的点蚀电位显著提高，有效地撸制点蚀，缓 蚀效率达８１－９５％温度、     

钼化合物在表面处理中的应用

归纳介绍了钼及其化合物的理化性能及其在腐蚀防护方面的应用。     

High effective organic corrosion inhibitors for 2024 aluminium alloy

The inhibiting effect of several organic compounds on the corrosion of 2024 aluminium alloy in neutral chloride solution was investigated in the present work. The candidates were selected based on the assumption that effective inhibitors should form highly insoluble complexes with components of AA2024. Along with organic complexing agents, the salts of rare-earth elements were included into screening electrochemical impedance spectroscopy (EIS) test for getting comparative data. Results of EIS analysis revealed three most effective organic inhibitors: salicylaldoxime, 8-hydroxyquinoline and quinaldic acid. Their anti-corrosion performance was additionally investigated via dc polarization, as well as localized techniques: scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy coupled with scanning Kelvin probe (SKPFM). Localized measurements at exactly the same microdimensional zones of the alloy before and after immersion into 0.05 M sodium chloride solution allowed tracing the evolution of the Volta potential, chemical composition, surface topography and formation of corrosion products on the surface and intermetallic inclusions during the corrosion tests. The results show that the quinaldic acid, salicylaldoxime and 8-hydroxyquinoline provide anti-corrosion protection for AA2024 forming a thin organic layer of insoluble complexes on the surface of the alloy. Inhibiting action is the consequence of suppression of dissolution of Mg, Al and Cu from the corrosion active intermetallic zones.     

过氧化物/TAIC/阻聚剂交联体系在硅橡胶中的应用

研究了不同过氧化物/异氰尿酸三烯丙酯(TAIC)/阻聚剂交联体系在硅橡胶中的应用,对不同交联体系的硫化特性、物理性能、耐热老化性能和压缩永久变形性能进行了测试,并分别与抗焦烧型过氧化物交联剂进行了对比。结果表明:过氧化物/TAIC/阻聚剂交联体系交联的硅橡胶具有卓越的抗焦烧性能,其焦烧时间都优于参比的抗焦烧型过氧化物交联剂,同时,也都具有较好的耐热老化性能和压缩永久变形性能。     

Fault-tolerant hybrid epoxy-silane coating for corrosion protection of magnesium alloy AZ31

In this work, a hybrid epoxy-silane coating was developed for corrosion protection of magnesium alloy AZ31. The average thickness of the film produced by dip-coating procedure was 14 μm. The adhesion strength of the epoxy-silane coating to the Mg substrate was evaluated by pull-off tests and was found to be higher than 16 MPa both in dry and wet conditions. The hybrid epoxy-silane coating showed high corrosion resistance both when intact and when punched through by a needle. The low frequency impedance of intact coating was higher than 1 GΩ cm² after one month of immersion in 3.5% NaCl solution. Both, artificially induced defects and corrosion sites that appeared on the metal surface did not propagate. Their passivation behavior, that we call fault-tolerance, was observed by EIS, SVET-SIET and SEM-EDS. It was ascribed to the good adhesion, high coating integrity and corrosion inhibiting effect provided by diethylenetriamine used as epoxy hardener.     

Corrosion of carbon steel in sodium methanoate solutions

The behaviour of steel electrodes in sodium methanoate solutions was studied by coupling electrochemical techniques (voltammetry, OCP vs. time) with in situ micro-Raman spectroscopy analyses of the corrosion products. The polarisation curves depended strongly on the methanoate concentration. For the smallest concentration (10⁻³ mol L⁻¹), the current density increased regularly with the applied potential. So the behaviour of the electrode was typical of an active material. In contrast, for the largest concentration (10⁻¹ mol L⁻¹), the curves obtained were typical of a passive material. Methanoate ions favoured growth and stability of a passive oxide film more likely by adsorbing on its surface. The polarisation curve obtained for the intermediate concentration (10⁻² mol L⁻¹) was unusual and testified of an imperfect passivation of the steel surface. Finally, steel electrodes were left at the open circuit potential in the methanoate solutions. In any case, the passivity was rapidly lost and a general corrosion of the surface took place. In situ Raman spectroscopy analyses at the early stage of the corrosion process demonstrated that the first product to form was a green rust, GR(HCOO⁻). It was oxidised later into γ-FeOOH (lepidocrocite) by dissolved O₂. The process is then typical of what is usually observed in neutral or alkaline media, whatever the anions present and responsible of the GR formation. A new and detailed characterisation of GR(HCOO⁻) by X-ray diffraction was performed and a crystal structure is proposed.     

高纯丙烯酸羟乙酯的新生产工艺

简要介绍了丙烯酸羟乙酯的几种反应合成路线,并对工业化生产采用的工艺路线进行简单评价。对上海华谊丙烯酸有限公司原有丙烯酸羟乙酯的生产工艺特点进行评述,并进一步就高纯丙烯酸羟乙酯的提纯生产工艺改良进行论证。