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Article
Publication date: 1 August 1964

Dr.S. Kut

IN many of the industrial and other aggressive environmental conditions encountered today a synthetic, plastics‐type of paint system must be used, since traditional paints…

Abstract

IN many of the industrial and other aggressive environmental conditions encountered today a synthetic, plastics‐type of paint system must be used, since traditional paints give poor and limited service. However, for these synthetic paints to be fully effective, they must be applied to more scrupulously prepared surfaces. The finer tolerances and more exacting application requirements of synthetic plastics‐type coatings, such as the epoxies, must be appreciated. Once these are understood it is not difficult to put the materials into use, where they give outstanding long‐term protection. Some of the physical, chemical and solvent‐resistance characteristics of the epoxy resin coatings can, of course, be attained with other synthetic paints, and all these materials have their place in the paint manufacturer's armoury. There are resins showing better flexibility and chemical or heat resistance than the epoxies, but the latter are outstanding in combining these and other characteristics to a marked degree—hence their fairly rapid user acceptance. There is inevitably over‐lapping in characteristics with other coatings, particularly the polyurethanes, and it is not claimed here that epoxy coatings can confer protection against all corrosive environments.

Details

Anti-Corrosion Methods and Materials, vol. 11 no. 8
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 May 1984

Americus

HIGH SOLIDS COATINGS Review Articles Without question, the major motivation for high solids coatings is government regulations. An interesting article which summarises…

Abstract

HIGH SOLIDS COATINGS Review Articles Without question, the major motivation for high solids coatings is government regulations. An interesting article which summarises what the coatings industry has done in order to meet air pollution regulations in the United States has been provided by Burger (Metal Finishing, July, 1982, p. 59). His list includes, in addition to high build and solventless coatings, electrodeposition, electrostatic powder coatings, Rule 66—acceptable solvent‐based coatings, and water‐borne coatings. Air pollution results not only from solvents but from the particulates released during surface preparation. Pollution due to surface preparation has been alleviated by the use of white water sandblasting, centrifugal and rotary blast cleaning blast cleaning with carbon dioxide pellets, improved ventilation air filters and safety equipment, plasma arc and laser cleaning, sonic cleaning, special chemical cleaning, and surface preparation and vacuum blasting. In addition, solvent recovery units have been utilised extensively in industrial coatings.

Details

Pigment & Resin Technology, vol. 13 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 2 January 2018

Joseph Raj Xavier

This paper aims to investigate the effect of introducing nano-ceria (CeO2) particles to the epoxy coatings on mild steel in natural seawater.

Abstract

Purpose

This paper aims to investigate the effect of introducing nano-ceria (CeO2) particles to the epoxy coatings on mild steel in natural seawater.

Design/methodology/approach

The epoxy–ceria nanoparticles were coated with mild steel using a wire-wound draw-down bar method. The effects of ceria nanoparticles on the corrosion resistance of epoxy-coated samples were analyzed using scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS).

Findings

Localized measurements such as oxygen consumption and iron dissolution were observed using SECM in natural seawater in the epoxy-coated sample. The increase in film resistance (Rf) and charge transfer resistance (Rct) values by the addition of nano-ceria particles in the epoxy coating was measured from EIS measurements after wet and dry cyclic corrosion test. Scanning electron microscope (SEM)/energy dispersive X-ray spectroscope (EDX) analysis showed that complex oxides of nano-ceria were enriched in corrosion products at a scratched area of the coated mild steel after corrosion testing. Focused ion beam-transmission electron microscope (FIB-TEM) analysis confirmed the presence of the nanoscale oxide layers of ceria in the rust of the steel.

Research limitations/implications

The tip current at −0.70 V for the epoxy–CeO2-coated sample decreased rapidly because of cathodic reduction of the dissolved oxygen. The increase in film resistance (Rf) and charge transfer resistance (Rct) values by the addition of nano-ceria particles in the epoxy coating were measured from EIS measurements after wet and dry cyclic corrosion test.

Practical implications

The presence of complex oxide layers of nano-ceria layers protects the coated steel from rusting.

Social implications

The use of this nano-ceria for corrosion protection is environment-friendly.

Originality/value

The results of this study indicated the significant effect of nano-ceria particles on the protective performance and corrosion resistance of the epoxy coating on mild steel. The dissolution of Fe2+ was lower in the epoxy–ceria nanoparticle-coated mild steel than that of the epoxy-coated mild steel resulting in a lower anodic current of steel. The increase in film resistance and the charge transfer resistance showed that the nano-ceria particles and the formation of complex oxides provide better barrier protection to the coating metal surfaces.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 1 September 1964

Dr.S. Kut

In part one of this article (August 1964) the author dealt with the general chemistry, curing characteristics and applications of two‐pack and coal tar‐epoxy coatings

Abstract

In part one of this article (August 1964) the author dealt with the general chemistry, curing characteristics and applications of two‐pack and coal tar‐epoxy coatings. Part two discusses other types of epoxies and describes their uses as corrosion‐resistant coatings and pipe linings.

Details

Anti-Corrosion Methods and Materials, vol. 11 no. 9
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 May 1983

Americus

Epoxy resins have probably provided more interesting chemistry than any other polymer the paint industry uses. In this category of interesting chemistry is Russian work …

Abstract

Epoxy resins have probably provided more interesting chemistry than any other polymer the paint industry uses. In this category of interesting chemistry is Russian work [World Surface Coatings Abstracts (1978) Abstract No. 1558] which describes the preparation of structurally coloured epoxy resins — i.e. of epoxy resins which are inherently coloured. The work involves condensing bisphenol A and epichlorohydrin in the presence of small amounts (0.1 to 0.5 weight per cent) of a coloured co‐monomer dye. The dye, for example, can be the glycidyl ether of alpha aminoanthroquinone. Coloured products resulted which presumably would provide coatings with intrinsic colour. Of course, this colour could be modified by extrinsic dyes and pigments. The concept of producing coloured polymers is not a new one. One approach to making black polyethylene for black film is to carry out the polymerisation of the ethylene in a fluid bed of carbon particles. The carbon particles presumably serve as a nucleus around which the polymer forms and at the same time serves to impart a black colour to the polymer particle. This technology has never been commercialised but it is certainly of interest to the paint chemist for it presents a new concept in carrying out a major objective of the paint industry — namely, to impart colour to solutions of polymers.

Details

Pigment & Resin Technology, vol. 12 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 February 1995

Sumeet Trehan and M.C. Shukla

The acute shortage coupled with tremendous increase in cost of various solvents used by paint industry and pollution becoming a serious concern has resulted in intensive…

Abstract

The acute shortage coupled with tremendous increase in cost of various solvents used by paint industry and pollution becoming a serious concern has resulted in intensive study of water‐borne coatings. Water‐borne coatings ideally meet the needs for coating systems which do not cause atmospheric pollutions and at the same time help in conservation of precious and renewable petroleum resources. Many research workers have developed water‐soluble epoxies, alkyds and acrylics to make water‐based surface coatings.

Details

Pigment & Resin Technology, vol. 24 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 6 August 2019

Sepideh Pourhashem, Alimorad Rashidi and Mohammad Reza Vaezi

In this research, the effect of graphene nanosheets and graphene quantum dots (GQDs) as carbon-based nanofillers on corrosion protection performance of epoxy coatings is…

Abstract

Purpose

In this research, the effect of graphene nanosheets and graphene quantum dots (GQDs) as carbon-based nanofillers on corrosion protection performance of epoxy coatings is considered.

Design/methodology/approach

Graphene nanosheets are synthesized via chemical vapor deposition method, and GQDs are synthesized by a simple and gram scale procedure from carbon black. The prepared nanofillers are characterized by X-ray diffraction technique, Fourier transform infrared spectroscopy and transmission electron microscopy. Further, solvent-based epoxy coatings containing 0.1 Wt.% graphene nanosheets and GQDs are prepared, and the corrosion resistance of nanocomposite coatings is considered by electrochemical impedance spectroscopy.

Findings

The results indicate that both epoxy/graphene nanosheets and epoxy/GQDs samples have significantly higher corrosion resistance than pure epoxy coating. Meanwhile, GQDs can more effectively enhance the corrosion protection performance of epoxy coatings compared to graphene sheets, which can be attributed to the presence of functional groups on GQDs and improving the dispersion quality in polymer matrice.

Originality/value

In this research, for the first time, the graphene quantum dots (GQDs) prepared by a “top-down” method from carbon black are used as nanofiller in epoxy coatings, and the potential application of graphene nanosheets and GQDs as anti-corrosion nanofiller in epoxy coatings is investigated.

Details

Industrial Lubrication and Tribology, vol. 71 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 26 June 2009

Kati Kokko, Hanna Harjunpää, Pekka Heino and Minna Kellomäki

The purpose of this paper is to investigate the influence of composite coating structure on the reliability of adhesive flip chip joints. The need for conformal coating is…

Abstract

Purpose

The purpose of this paper is to investigate the influence of composite coating structure on the reliability of adhesive flip chip joints. The need for conformal coating is considered, especially for medical applications, and medical sterilization is also considered.

Design/methodology/approach

Two test lots were assembled and one of them was sterilized using gamma sterilization. Both test lots were coated first with epoxy and then with Parylene C, resulting in a composite coating structure. The reliability was studied using a constant humidity test and the failure analysis was performed with cross‐sections and scanning electron microscopy analysis. These results were compared to earlier research results on conformal coatings.

Findings

The reliability of both test lots proved to be good. The composite coating structure shields the joints from humidity and improves the reliability compared to non‐coated test samples. When the conformal coating was compared to the pure Parylene C coated test lot, the reliability was almost the same. This leads to the conclusion that the epoxy layer in the composite coating structure has no value when long‐term reliability is considered. Gamma sterilization does not greatly affect reliability. The epoxy coating under the Parylene C layer cracked during reliability testing.

Originality/value

The paper shows the influence of composite coating structure on the reliability of adhesive flip chip joints, particularly important in medical applications.

Details

Soldering & Surface Mount Technology, vol. 21 no. 3
Type: Research Article
ISSN: 0954-0911

Keywords

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Article
Publication date: 4 December 2018

Reza Hosseini Rad, Mansoor Toorani and HamidReza Zarei

This paper aims to increase protection behavior of epoxy coating on aluminum alloys with plasma electrolitic oxidation (PEO) process as pretreatment and to investigate the…

Abstract

Purpose

This paper aims to increase protection behavior of epoxy coating on aluminum alloys with plasma electrolitic oxidation (PEO) process as pretreatment and to investigate the corrosion properties of duplex coating system on aluminum alloy.

Design/methodology/approach

The study used micro structure study, electrochemical impedance spectroscopy (EIS) investigation, water uptake investigation and pull-off test.

Findings

This study was done to investigate the effect of urea as an additive, which alters the current density and time of process parameters in the protective performance of epoxy coating on the aluminum substrate. The protective behavior of double-layer coatings was examined using EIS in 3.5 per cent NaCl solution. In addition, the adhesion strength of double-layer coatings was evaluated using pull-off test, and the results demonstrated that the adhesion strength of sample with higher content of urea and current density is about two times that of sample without PEO preparation.

Originality/value

The protective properties and adhesion strength of epoxy coating can be increased with PEO pretreatment.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 3 May 2016

L. Ismail, K. Ramesh, N.A. Mat Nor, S.K.M. Jamari, B. Vengadaesvaran and A.K. Arof

The purpose of this paper is to study the electrochemical, mechanical and thermal characteristics of polyester – epoxy coating systems using electrochemical impedance…

Abstract

Purpose

The purpose of this paper is to study the electrochemical, mechanical and thermal characteristics of polyester – epoxy coating systems using electrochemical impedance spectroscopy (EIS), pull-off test and differential scanning calorimetry (DSC). These are very important properties to evaluate the performance of a coating system. Proper measurement and analysis techniques are needed for a proper evaluation of these properties to ensure the coating performance.

Design/methodology/approach

Different ratios of polyester and epoxy resins have been blended to formulate good anticorrosive, mechanically strong and thermally stable binder coating system. EIS, pull-off test and DSC were used to evaluate these properties.

Findings

The sample containing 90 wt.% polyester exhibited the best corrosion resistance from the beginning until the end of exposure time. The value of corrosion resistance (Rc) obtained on the 30th day of exposure was found to be 2.89 × 108 ohm cm−2. The glass transition temperature (Tg) was found to be increasing with the incorporation of epoxy to the binder system. The result from pull-off test showed the best adhesion with the sample containing 90 wt.% polyester which also has the lowest Tg promoted better adhesion properties.

Practical implications

The curing time must be reduced for practical applications.

Originality/value

Hybrid coatings systems have been formulated. This paper discusses on the highest coating resistance obtained polymer-substrate mechanical properties and thermal characteristic of the polyester/epoxy binder resin using DSC.

Details

Pigment & Resin Technology, vol. 45 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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