scholarly journals Study on a Novel Recyclable Anticorrosion Gel Coating Based on Ethyl Cellulose and Thermoplastic Polyurethane

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 618 ◽  
Author(s):  
Hailong Zhang ◽  
Junlei Tang ◽  
Hongchang Han ◽  
Shengwei Zhang ◽  
Hu Wang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Corrosion Protection ◽  
Ethyl Cellulose ◽  
Electrochemical Impedance ◽  
Raw Materials ◽  
Thermoplastic Polyurethane ◽  
Salt Spray ◽  
Mineral Oil ◽  
Mechanical Analysis ◽  
Salt Spray Test

In this paper, ethyl cellulose, thermoplastic polyurethane, and mineral oil were used as the main raw materials to synthesize a recyclable thermoplastic gel for anticorrosion coatings by a hot melt method. In addition, the effect of thermoplastic polyurethane on the properties of the coating was discussed. The structure and corrosion protection properties of the coating were characterized and analyzed by a scanning electron microscope, transmission electron microscope, X-ray diffraction, infrared spectroscopy, dynamic mechanical analysis, salt spray test, and electrochemical measurements. The results show that the ethyl cellulose and oil in the coating can form a stable organic-gel structure by hydrogen bonding, and the mineral oil and castor oil are uniformly dispersed in the coating. The surface of the coating does not change after 3000 h of a salt spray test. During the repeated hot melting spraying and immersion in 3.5 wt.% NaCl solution for five times, the electrochemical impedance modulus of the coating was always above 109 Ω⋅cm2, the water absorption rate was always less than 1.5 wt.%, and the mechanical properties of the coating did not decrease. This novel coating could be used for the corrosion protection of flange and valve connections in pipeline and bolting connections in different industries. The disassembly and assembly operation of these connection structures during the regular maintenance will destroy the ordinary anticorrosion coating, and the irregular geometric shape of such places also make difficulties for the preparation of ordinary coatings onsite.

The study of the effectiveness of corrosion protection of zinc-rich coating on the base of water sodium silicate

2020 ◽  
Vol 25 (4) ◽  
Keyword(s):  
Corrosion Protection ◽  
Sodium Silicate ◽  
Electrochemical Impedance ◽  
Paint Film ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Test Method ◽  
Liquid Sodium ◽  
Research Station ◽  
Marine Research

The study is examines the assessment of the corrosion-protective properties of zinc-rich coating based on water sodium silicate (ZRC) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl reference electrode in 3 M solution of KCl, auxiliary electrode – Pt (8x8 mm) and working electrodes for determination potential (Ecorr) and impedance measurement, salt spray test method and natural teszzt method at Dam Bay Marine Research Station, Nha Trang, Khanh Hoa, Viet Nam. ZSC can provide good cathodic protection when zinc content is 70% by weight or more. ZSC with a mixing ratio of High Modulus Liquid Sodium Glass / Zinc Powde : 25/75 by weight (working title – TTL-VN) has good corrosion protection after 16 cycles salt spray test and after 18 months natural test in seawater. The paint film has basic parameters as adhesion – 4,41 MPa, flexural strength – 2 mm, pendulum hardness – 0,62 conventional units and initial coating potentia l – 0,96 V Ag/AgCl.

Studies on anticorrosion properties of polyaniline-TiO2 blended with acrylic-silicone coating using electrochemical impedance spectroscopy

2016 ◽  
Vol 45 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Siti Khumaira Mohd Jamari ◽  
Ramesh Kasi ◽  
Leeana Ismail ◽  
Nur Amirah Mat Nor ◽  
Ramis Rau Subramanian ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Protection ◽  
Water Uptake ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Corrosive Environment ◽  
Content Type ◽  
Silicone Coating

Purpose – The purpose of this paper is to study the performance of coatings for corrosion protection. In this research, different compositions of polyaniline (PANI) were added in a pigmented acrylic polyol-silicone coating. The important performance property is corrosion protection. The coatings must be evaluated under corrosive environment. Electrochemical impedance spectroscopy (EIS) is the suitable method to investigate the effect of the addition of PANI in the binder mixture. Design/methodology/approach – The coating resistance, coating capacitance, water uptake and the diffusion coefficient of the coatings were tested for each of the sample. These parameters of the coatings were tested for a period of 60 days of exposure of 3.5 weight per cent solution of sodium chloride salt. EIS results will be further verified by immersion test and salt spray test. Findings – Coating materials developed using 8 and 10 weight per cent of PANI exhibited better coating properties with higher coating resistance for a period 60 days immersion in corrosive environment compared to coatings with lower amount of PANI (2-6 weight per cent). The best coating system obtained the coating resistance value in the range of giga ohms even after the 60th day of exposure. The lowest capacitance value suggested that the coatings have not allowed the electrolyte to permeate to the interface. Water uptake values were found to be in the range of 5 per cent. Salt spray test results showed that the corrosion has initiated at the edges of the scratches only. Practical implications – The study of the effect of conducting polymers in acrylic polyol/silicone resin hybrid binder will be useful for more exploration in coating science. Originality/value – The development of protective hybrid coatings using conducting polymer and TiO2 particles is new. The results show high coating resistance values.

scholarly journals Design and Multidimensional Screening of Flash-PEO Coatings for Mg in Comparison to Commercial Chromium(VI) Conversion Coating

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Ewa Wierzbicka ◽  
Marta Mohedano ◽  
Endzhe Matykina ◽  
Raul Arrabal
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Chromium Vi ◽  
Alkaline Electrolytes ◽  
Az31b Alloy ◽  
Plasma Electrolytic

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations demand for an expedient discovery of a Cr(VI)-free alternative corrosion protection for light alloys even though the green alternatives might never be as cheap as current harmful technologies. In the present work, flash- plasma electrolytic oxidation coatings (FPEO) with the process duration < 90 s are developed on AZ31B alloy in varied mixtures of silicate-, phosphate-, aluminate-, and fluoride-based alkaline electrolytes implementing current density and voltage limits. The overall evaluation of the coatings’ anticorrosion performance (electrochemical impedance spectroscopy (EIS), neutral salt spray test (NSST), paintability) shows that from nine optimized FPEO recipes, two (based on phosphate, fluoride, and aluminate or silicate mixtures) are found to be an adequate substitute for commercially used Cr(VI)-based conversion coating (CCC). The FPEO coatings with the best corrosion resistance consume a very low amount of energy (~1 kW h m−2 µm−1). It is also found that the lower the energy consumption of the FPEO process, the better the corrosion resistance of the resultant coating. The superb corrosion protection and a solid environmentally friendly outlook of PEO-based corrosion protection technology may facilitate the economic justification for industrial end-users of the current-consuming process as a replacement of the electroless CCC process.

scholarly journals Graphene-Based Reinforcing Filler for Double-Layer Acrylic Coatings

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4499
Author(s):  
Massimo Calovi ◽  
Stefano Rossi ◽  
Flavio Deflorian ◽  
Sandra Dirè ◽  
Riccardo Ceccato
Keyword(s):  
Corrosion Protection ◽  
Double Layer ◽  
Abrasion Resistance ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
High Conductivity ◽  
Functionalized Graphene Oxide ◽  
Electron Microscopies ◽  
Joint Application ◽  
Acrylic Coatings

This study aims to demonstrate the remarkable features of graphene-based fillers, which are able to improve the protective performance of acrylic coatings. Furthermore, the joint application of a cataphoretic primer and a spray top coat, containing graphene and functionalized graphene oxide flakes, respectively, enables the deposition of a double-layer coating with high conductivity and abrasion resistance properties, capable of offering excellent corrosion resistance to the metal substrate. The surface morphology of the single- and double-layer coatings was investigated by optical and electron microscopies, analysing the defectiveness introduced in the polymer matrix due to the filler agglomeration. The behavior in aggressive environments was assessed by exposure of the samples in the salt spray chamber, evaluating the blister formation and the adhesion level of the coatings. Electrochemical impedance spectroscopy measurements were employed to study the corrosion protection properties of the coatings, whose conductivity and abrasion resistance features were analysed by conductivity assessment and scrub tests, respectively. The incorporation of graphene-based fillers in the cataphoretic primer improves the corrosion protection properties of the system, while the graphene flakes provide the top coat spray layer with high conductivity and excellent abrasion resistance features. Thus, this work demonstrates the possibility of employing different types of graphene-based fillers and deposition methods for the creation of multifunctional coatings.

Epoxy Resin Modified with PEDOT/PSS and Corrosion Protection of Steel

2012 ◽  
Vol 560-561 ◽  
pp. 947-951
Author(s):  
Jian Hou ◽  
Guang Zhu ◽  
Jing Kun Xu ◽  
Jun Tao Wang ◽  
Yao Huang
Keyword(s):  
Electron Microscope ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Scanning Electron Microscope ◽  
Epoxy Resin ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Protection Efficiency ◽  
Epoxy Paint ◽  
Scanning Electron

An epoxy paint containing PEDOT/PSS was described herein. The corrosion behavior of steel samples coated with the paint was investigated in seawater. For this purpose, electrochemical impedance spectroscopy was utilized and surface morphology of coatings after corrosion was observed using scanning electron microscope. It was found that the addition of small PEDOT/PSS to the epoxy resin increased its corrosion protection efficiency. Meanwhile, the possible mechanism was discussed.

scholarly journals Corrosion protection and antifouling properties of varnish-coated steel containing natural additive

2017 ◽  
Vol 23 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Besheir Abd-El-Nabey ◽  
Sherif El-Housseiny ◽  
Essam Khamis ◽  
Ashraf Abdel-Gaber
Keyword(s):  
Corrosion Protection ◽  
Visual Inspection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Coated Steel ◽  
Nacl Solution ◽  
Cannabis Extract ◽  
Steel Panels ◽  
Natural Additive ◽  
Peeling Off

The corrosion protection and antifouling properties of varnish-coated steel panels containing different amounts of cannabis extracts were investigated using electrochemical impedance spectroscopy (EIS), salt spray and immersion tests in 0.5 M NaCl solution and subjected to a field test in seawater. Analysis of the experimental data showed that the presence of cannabis extract resisted the deterioration (peeling off) tendency of the varnish-coated steel panels exposed to aggressive environments. Visual inspection showed that the cannabis extract also provided good antifouling properties.

A Comparative Study of Neat Epoxy Coating and NanoZrO2/Epoxy Coating for Corrosion Protection on Carbon Steel

2014 ◽  
Vol 599-601 ◽  
pp. 3-6
Author(s):  
Xia Zhao ◽  
Shuan Liu ◽  
Bao Rong Hou
Keyword(s):  
Carbon Steel ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Epoxy Coating ◽  
Steel Plates ◽  
Neat Epoxy ◽  
Corrosive Media ◽  
Tafel Polarization ◽  
Q235 Carbon Steel

nanoZrO2 was modified by styrene coupling grafting method and then used as an additive to improve the protective performance of epoxy coating. Two kinds of coatings, neat epoxy coating and nanoZrO2/epoxy coating, were prepared and applied on Q235 carbon steel plates. The plates were submitted to salt spray chamber and seawater immersion for 1000 hours to evaluate the corrosion protection performance for these two kinds of coatings. Tafel polarization curves and electrochemical impedance spectroscopy (EIS) were determined to analyze the corrosion behavior of coating/metal system. Scanning electron microscopy (SEM) and photographs were carried out for morphology analysis of two kinds of coatings under different conditions. Results showed a superior stability and efficient corrosion protection by nanoZrO2 /epoxy coating. The modified nanoZrO2 could inhibit the penetration of corrosive media and then improve the corrosion protection of the epoxy coating on carbon steel.

Corrosion Protection of Aluminum Alloy 2024-T3 by Vanadate Conversion Coatings

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 284-296 ◽  
Author(s):  
H. Guan ◽  
R. G. Buchheit
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Protection ◽  
Inductively Coupled Plasma ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Self Healing ◽  
Pitting Potential ◽  
X Ray ◽  
Aluminum Alloy 2024

Abstract In this paper, the formation, chemistry, morphology, and corrosion protection of a new type of inorganic conversion coating is described. This coating, referred to as a vanadate conversion coating (VCC), forms on aluminum alloy substrates in a matter of minutes during simple immersion in aqueous vanadate-based solutions at ambient temperatures. VCCs are yellow in color and conformal across the surface of aluminum alloy 2024-T3 (AA2024-T3 [UNS A92024]) substrates. Auger electron sputter depth profiles and x-ray absorption near-edge spectroscopy show that VCCs formed by a 3-min immersion are 300 nm to 500 nm thick and consist of a mixture of vanadium oxides and other components in the coating bath. In anodic polarization experiments conducted in aerated chloride solutions, VCCs increase the pitting potential and decrease the rate of oxygen reduction. When characterized by electrochemical impedance spectroscopy, VCCs demonstrate a low-frequency impedance between 1 MΩ-cm2 and 2 MΩ-cm2 after 24 h exposure to aerated 0.5 M sodium chloride (NaCl) solutions. In salt spray testing conducted according to ASTM B117, VCCs suppress formation of large pits for more than 168 h. VCCs also appear to be self-healing. Analysis of solution in contact with VCCs by inductively coupled plasma emission spectroscopy indicates that vanadate is released into solution upon exposure. Vanadium deposits were identified by x-ray microchemical analysis on a bare alloy substrate held in close proximity to a vanadate conversion-coated surface, and corrosion resistance of this bare surface was observed to increase during exposure. An important component of VCC formation appears to involve inorganic polymerization of V5+, which leads to the buildup of a film that passivates the surface and inhibits corrosion.

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