Acetyl thiourea chitosan as an eco-friendly inhibitor for mild steel in sulphuric acid medium

Acetyl thiourea chitosan polymer (ATUCS) has been synthesized and evaluated as corrosion inhibitor. The electrochemical behavior of mild steel in naturally aerated 0.5 M H₂SO₄ acid containing different concentrations of ATUCS has been studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) measurements and surface examination via scanning electron microscope (SEM) technique. The results of EIS showed that the resistance (R_t) increases slightly with increasing immersion time indicating a slight decrease in corrosion rate of the steel with time. Also, the corrosion rate increases with either increasing temperature or decreasing the polymer concentration as observed by polarization technique. Electrochemical impedance spectroscopy measurements under open-circuit conditions confirmed well polarization results. ATUCS has shown very good inhibition efficiency (IE) in 0.5 M sulphuric acid solution reaches to 94.5% for 0.76 mM concentration. IE of this compound has been found to vary with the concentration of the polymer solution, immersion time and temperature.     

Polygonatum odaratum extract as an eco-friendly inhibitor for aluminum corrosion in acidic medium

The corrosion of aluminum specimens in Polygonatum odaratum (P. odaratum) extract was studied using weight loss measurements, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy (SEM), and electron dispersive X-ray spectroscopy (EDX) techniques. The inhibition efficiency of the aluminum specimens in the presence of inhibitor from P. odaratum plant extract at 303–333 ± 1 K was evaluated with the weight loss technique. The results indicate the inhibition efficiency of P. odaratum plant extract increased with increased concentration of the inhibitor and decreased temperature in an acidic medium. The corrosion inhibition properties of the P. odaratum plant extract for aluminum specimen corrosion in 1 M HCl were analyzed using polarization studies and electrochemical impedance studies, which clearly showed a mixed-type inhibitor. UV-visible spectroscopy, Fourier transform infrared (FT-IR), SEM, and EDX revealed the surface morphology in the presence and absence of inhibitor on the metal surface. The results indicated the feasibility of using the P. odaratum plant extract as a corrosion inhibitor in acid environments.     

氢氟酸介质中铝缓蚀剂的研制与评价

研制了一种氢氟酸介质中铝缓蚀剂,并采用了失重法、电化学方法和金相显微镜分析法对该缓蚀剂进行了评价.实验结果表明,该缓蚀剂具有优良的缓蚀性能、抗高温性能、抗干扰性能和抗非均匀腐蚀性能.研究结果表明,该缓蚀剂在氢氟酸质量分数不大于10%、温度不高于60℃时,对铝具有优良的缓蚀作用.该缓蚀剂属于混合型缓蚀剂,同时抑制阳极过程和阴极过程.在该缓蚀剂存在的氢氟酸介质中,铝不产生点蚀、晶间腐蚀等非均匀腐蚀现象.     

Luffa aegyptiaca leaves extract as corrosion inhibitor for mild steel in hydrochloric acid medium

The performance of methanol extract of Luffa aegyptiaca leaves (MLA) as corrosion inhibitor for mild steel (MS) in 1 M HCl was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. Polarization measurements showed that the MLA acts as a mixed inhibitor. It was found that the percentage inhibition efficiency increased with MLA concentration and decreased with temperature. Thermodynamic parameters indicate the spontaneous adsorption of MLA on MS surface. In addition, it has been established that the adsorption process obeyed Langmuir isotherm. Additions of halide ions considerably increase the inhibition efficiency. Synergistic parameters confirm the synergistic effect of halide ions. The adsorption of the chemical constituents of MLA on MS surface was confirmed by Fourier transform infrared spectroscopy and atomic force microscopy.     

Extraction and experimental studies of Citrus aurantifolia as an economical and green corrosion inhibitor for mild steel in acidic media

The Citrus aurantifolia leaves extract was tested for corrosion inhibition on the mild steel in a 0.5?M sulfuric acid solution using weight loss, Tafel and EIS. The state of mixed adsorption with the potentiodynamic polarization effect is shown. Citrus aurantifolia showed the strongest corrosion inhibition of 96.46% at a concentration of 250?mg/L. SEM and AFM are used to verify the formation of a protective layer on the surface of mild steel. The adsorption phenomenon was verified using UV-Vis. spectroscopic technique, whereas FT-IR confirmed the presence of several functional groups containing heteroatoms. Adsorption of the inhibitory molecules on the mild steel surface followed the Langmuir adsorption isotherm. All obtained results ensure that C. aurantifolia leaves extract can form an effective blocking layer and control the corrosion process.     

Hyperbranched poly(cyanurateamine): A new corrosion inhibitor for mild steel in hydrochloric acid medium

Hyperbranched poly(cyanurateamine) (POCYAM) was tested as a novel corrosion inhibitor for mild steel in 0.5–3 M HCl using chemical and electrochemical techniques at 25–70 °C. The results show that this compound has good corrosion inhibiting properties for mild steel in HCl at very low concentrations. Corrosion inhibition efficiency rises with POCYAM concentration. The adsorption of the POCYAM onto the mild steel surface obeys Langmuir adsorption isotherm model. The inhibition mechanism was further corroborated by the values of thermodynamic parameters obtained from the experimental data.     

高环烷酸原油缓蚀剂的性能评价研究

本文介绍了自行开发的缓蚀剂A与国外缓蚀剂B对环烷酸的缓蚀评价,利用扫描电镜对缓蚀剂吸附膜进行了分析。实验结果表明：在270℃左右,酸值4.0 mgKOH/g的腐蚀介质油中,高温缓蚀剂A、B在金属表面成膜较好,能有效地抑制环烷酸腐蚀。     

盐酸介质中新型缓蚀剂研发进展

对盐酸介质中金属材质腐蚀的机理以及研究现状进行了分析和概述。对缓蚀剂的研发做出了展望。     

高温硫酸体系中碳钢缓蚀剂的研究

在任何温度下,60%以下的硫酸对碳钢的腐蚀速率都随着酸质量分数增大而提高。随着条件,如温度、流速等因素的提高,这种腐蚀还会加剧。针对高温硫酸酸洗环境,研究开发出一种缓蚀剂。通过试验发现,该缓蚀剂在(65±5)℃时,60%以下的硫酸酸洗环境中表现出较好的缓蚀效果,最佳质量分数推荐为1.5%～2.5%。     

Amphiphilic maleic acid copolymers as corrosion inhibitors for aluminum pigment

Aluminum pigments react in aqueous alkaline media (e.g., water-borne paints) by the evolution of hydrogen. Maleic acid copolymers, which were synthesized by copolymerization of maleic acid anhydride, styrene, and acrylic esters (ethyl-, n-butyl-, n-hexyl-, n-dodecyl-, and n-octadecyl acrylate) inhibit this corrosion reaction. With the increasing chain length of the ester alcohol of the acrylate monomer, the evolved hydrogen volume decreases (i.e., the corrosion inhibiting effect increases). There seems to be a potential correlation between the number of carbon atoms of the ester alcohol of the copolymers and the evolved hydrogen volumes. With the addition of 0.5 wt % of the copolymers with n-butyl, n-hexyl, n-dodecyl-, and n-octadecyl acrylate no hydrogen evolution was observed at pH 8 within 21 days (complete corrosion inhibition). Conductivity measurements of aqueous copolymer solutions indicate that with an increasing chain length of the ester alcohol, the copolymers possibly associate by hydrophobic bonding. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2169–2174, 1998     

Ceftriaxone: a novel corrosion inhibitor for mild steel in hydrochloric acid

Corrosion inhibition of mild steel in 1 N HCl by Ceftriaxone was studied by polarization resistance, Tafel polarization, EIS, and weight loss measurement. The inhibitor showed more than 90% inhibition efficiency at optimum concentration of 400 ppm. Results obtained revealed that inhibition occurs through adsorption of the drug on the metal surface without a modification of the mechanism of the corrosion process. Potentiodynamic polarization suggests that this is a mixed type of inhibitor. Electrochemical impedance spectroscopy was used to investigate the mechanism of corrosion inhibition. Thermodynamic parameters such as E _a, ΔH, ΔS, ΔG and Q were calculated to investigate the mechanism of inhibition. All the investigations suggested that the compound follows the Langmuir adsorption isotherm.     

氟硼酸体系中三聚磷酸钠对铝的吸附及缓蚀作用

采用失重法研究了氟硼酸体系中三聚磷酸钠对铝的吸附及缓蚀作用,并应用吸附理论和Sekine方法对实验数据进行处理,发现三聚磷酸钠在氟硼酸溶液中在铝表面上产生了吸附,且低质量浓度下吸附规律基本符合Langmuir等温式,缓蚀率随温度和浓度的增大而增大.根据这些结果,讨论了吸附与缓蚀作用之间的关系,并获得了吸附过程△H°,△S°和△G°等重要热力学参数.     

Experimental and computational investigations of 2-amino-6-bromobenzothiazole as a corrosion inhibitor for copper in sulfuric acid

2-amino-6-bromobenzothiazole (ABBT) as an inhibitor of copper corrosion in 0.5 M H₂SO₄ solution was researched in this study using with electrochemical measurement, scanning electron microscope, atomic force microscope, and theoretical calculation. Polarization curves manifest that ABBT acts as a modest cathodic-type inhibitor with a maximum achievable inhibition efficiency of 94.6% at 1 mM. EIS test indicates that ABBT adsorb on the copper surface and form an adsorption film, which obeys Langmuir adsorption model. Furthermore, DFT calculation and molecular dynamics simulation were utilized to explore the mechanism of inhibition of ABBT.     

硫磺制酸装置露点腐蚀问题的分析

分析了硫磺制备酸容易发生露点腐蚀的原因。硫磺中的有机物、水分、游离硫酸均可能增加炉气水分含量，相应提高了炉气露点温度，加之省煤器进水温度低，则容易发生露点腐蚀。采用优质硫磺作原料，在省煤器低温段采用热管元件等可有效地解决硫磺制酸露点腐蚀问题。     

盐酸酸洗缓蚀抑雾剂MY的研究

研制的一种适用于碳钢在高温盐酸中酸洗除锈的MY缓蚀抑雾剂,是以合成的一种咪唑啉季铵盐与其他化合物复配得到的混合物。采用静态失重法和中和滴定法对其缓蚀抑雾性能进行评价,并对其缓蚀机理进行探讨。结果表明,MY缓蚀抑雾剂在20%盐酸中,酸洗温度为80℃,用量为0.5%时,缓蚀效率达95%以上,抑雾效率达到90%以上,对改善作业环境,综合治理环境污染具有积极的作用。     

The role of cuprous ion as corrosion inhibitor for copper in a chloride medium

A disconnected Al or Zn strip was found to possess corrosion-inhibition effect on copper in a chloride solution. Original assumption of a pseudo-cathodic protection mechanism was later experimentally proved to be unfounded. A chemical reason was proposed to explain the phenomena.     

有机膦酸缓蚀剂的研究发展现状

介绍了缓蚀剂的类型、缓蚀机理和缓蚀性能,比较了各种缓蚀剂的特点,认为有机膦缓蚀剂具有无毒性、污染小的特点,尤其在应用于高硬度、高pH值和高温水系统时有较好的表现。     

A comprehensive evaluation of mimosa extract as a corrosion inhibitor on AA6060 alloy in acid rain solution: part I. Electrochemical AC methods

The inhibition effect of mimosa extract on the corrosion of AA6060 aluminum alloy in acid rain solution was investigated by electrochemical impedance spectroscopy and dynamic electrochemical impedance spectroscopy (DEIS). All the studied electrochemical parameters showed good corrosion inhibitive characteristics with respect to the aluminum alloy in the tested solution. Inhibitor efficiency increased with the concentration and attained 45% at 2750 ppm. The advantage of DEIS as a tool for the investigation of corrosion inhibitor influence was discussed.     

Performance assessment of poly (methacrylic acid)/silver nanoparticles composite as corrosion inhibitor for aluminium in acidic environment

This article reports the preparation of poly (methacrylic acid)/silver nanoparticles composite (PMAA/AgNPs) by in situ mixing of aqueous solutions of PMAA and 1 mM AgNO₃ with natural honey as reducing and stabilizing agent. The prepared PMAA/AgNPs composite was characterized by UV–vis spectroscopy, Fourier transformed infrared, X-ray diffraction and energy dispersive spectroscopy (EDS) while the morphology of the AgNPs in the composite was obtained by transmission electron microscopy (TEM). TEM results revealed that the AgNPs were spherical in shape. The performance of PMAA/AgNPs composite as anticorrosion material for Al in acidic environment was examined by electrochemical, weight loss methods, complemented by surface analysis characterization with scanning electron microscopy (SEM), EDS and water contact angle measurements. Results obtained indicate that PMAA/AgNPs composite is effective corrosion inhibitor for Al in an acid-induced corrosive environment. Inhibition efficiency increased with increase in composite concentration but decreased with rise in temperature. From potentiodynamic polarization results, PMAA/AgNPs composite is found to function as a mixed-type corrosion inhibitor. The adsorption of the composite onto Al surface was found to follow El-Awady et al. adsorption isotherm model. SEM, EDS and water contact angle results confirmed the adsorption of the composite on Al surface.