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Polyaniline (PANI) has garnered attention for its potential applications in anticorrosion fields because of its unique properties. Satisfactory outcomes have been achieved when using PANI as a functional filler in organic coatings. More recently, research has extensively explored PANI-based organic coatings with self-healing properties. The purpose of this paper is to provide a summary of the active agents, methods and mechanisms involved in the self-healing of organic coatings.

This study uses specific doped acids and metal corrosion inhibitors as active and self-healing agents to modify PANI using the methods of oxidation polymerization, template synthesis, nanosheet carrier and nanocontainer loading methods. The anticorrosion performance of the coatings is evaluated using EIS, LEIS and salt spray tests.

Specific doped acids and metal corrosion inhibitors are used as active agents to modify PANI and confer self-healing properties to the coatings. The coatings’ active protection mechanism encompasses PANI’s own passivation ability, the adsorption of active agents and the creation of insoluble compounds or complexes.

This paper summarizes the active agents used to modify PANI, the procedures used for modification and the self-healing mechanism of the composite coatings. It also proposes future directions for developing PANI organic coatings with self-healing capabilities. The summaries and proposals presented may facilitate large-scale production of the PANI organic coatings, which exhibit outstanding anticorrosion competence and self-healing properties.

Organic coatings are widely used for protecting metal equipment and structures from corrosion. Accurate detection and evaluation of the protective performance and service life of coatings are of great importance. This paper aims to review the research progress on performance evaluation and lifetime prediction of organic coatings.

First, the failure forms and aging testing methods of organic coatings are briefly introduced. Then, the technical status and the progress in the detection and evaluation of coating protective performance and the prediction of service life are mainly reviewed.

There are some key challenges and difficulties in this field, which are described in the end.

The progress is summarized from a variety of technical perspectives. Performance evaluation and lifetime prediction include both single-parameter and multi-parameter methods.

Organic and immersion metallic coatings are being used as a replacement for the hot air solder level (HASL) process. Use of these coatings provides advantages for both the fabricator and assembler. Advantages to assemblers include flatter pads (0.25‐0.5 micron thickness), no limitations on fine pitch or small hole cleaning, and greater solder joint strength. Advantages to the fabricator include lower operating costs, little or no rejects/rework, reduced safety hazard and a more environmentally friendly process. Current problems associated with the organic and immersion coatings include the inability to assess the solderability of the bare copper or the integrity of the coating (organic). These coatings also present a critical concern due to their reduced shelf life and potential inability to survive mishandling in manufacturing. Real time, non‐destructive methods of rapidly assessing the integrity these coatings are currently not available to the electronics industry. Surface Spectroscopy measurement techniques have the potential to measure the structure and characteristics of the organic and metallic coatings, and surface oxides that develop with time and temperature. The measurement techniques are rapid, non‐contact, and relatively inexpensive to make when compared to existing methods. Surface Spectroscopy can also provide critical surface information that is needed to troubleshoot solderability problems. The American Competitiveness Institute in association with the Navy EMPF program is working with several industry partners to develop a usable surface spectroscopy tool that will assess the quality and integrity of the coatings and correlate that reading with a solderability evaluation.

Background In the language of the steel industry, the term coated steel means, for all practical purposes, mild steel sheet or strip which is coated before it leaves the steel mill. Various coatings are employed depending upon product end use but basically they divide up into metallic coatings such as tin, zinc or aluminium; and organic coatings which are essentially paints or plastic films. Organic coatings are very often applied on top of metallic coatings, so that in the most advanced coated products there may be as many as five separate layers of material between the underlying steel and the exposed outer surface.

Organic coatings are one of the most widely applied methods for corrosion protection of metallic materials such as the tubing used in sour gas field. However, such coatings usually encounter the risk of failure due to the harsh and complex environment. Therefore, the study of failure of the organic coating is highly significant.

In this paper, the effects of Cl-concentration, HCl content, hydrogen sulfide/carbon dioxide (H₂S/CO₂), temperature and flow rate on the failure of epoxy-phenolic coating on the internal surface of BG90S steel tubing were investigated using adhesion force measurement, metallographic microscope, electrochemistry impedance spectroscopy and Fourier transform infrared spectroscopy.

The results show that the Cl-concentration, HCl content and H₂S/CO₂ do not affect the failure process too much as the ion concentration increased. However, the flow rate at the high temperature is the most important factor affecting the corrosion resistance of the inner coating tubing. With the increase of the flow rate, the pore resistance of the coating shows a decreasing trend, and the rate of decrease in pore resistance is first rapid and then slow. It demonstrates that the penetration speed of the electrolyte solution into the coating varied from fast to slowly. A weakening influence of the flow rate on the penetration failure of the inner coating can be found as the increase of the flow rate. Once the HS-ions penetrate through the coating and reach at the coating/steel interface where H₂ could be formed through the adsorption reaction, the coating failure occurs.

The failure of the coating depends on the penetration rate of water and ions, with the presence of exposed or punctured holes is accelerated and HS- was adsorpted by substrate Fe, and form H2 molecules between the coatings and substrate, that results failure of coatings.

This study aims to provide a model to predict the service life of a thick organic coating.

A series of thin coating films are rapidly tested under the same exposure condition as the thick coating in its service condition by means of electrochemical impedance spectroscopy, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction.

The validity of the model is successfully verified. The long-term protectiveness or service life of a thick organic coating can be rapidly predicted.

The prediction model does not require long-term experiments or any test that may alter the degradation mechanism of the thick coating.

Substitution of lead‐free solders in electronic assemblies requires changes in the conventional Sn:Pb finishes on substrates and component leads to prevent contamination of the candidate solder. Options for solderability preservative coatings on the printed wiring board include organic (azole or rosin/resin based) films and tin‐based plated metallic coatings. This paper compares the solderability performance of electroless tin coatings versus organic azole films after exposure to a series of humidity and thermal cycling conditions. It is shown that the solderability of immersion tin is directly related to the tin oxide growth on the surface and is not affected by the formation of Sn‐Cu intermetallic phases as long as the intermetallic phase is protected by a surface Sn layer. For a nominal tin thickness of 60 ?inches, the typical thermal excursions associated with assembly were not sufficient to cause the intermetallic phase to consume the entire tin layer. Exposure to elevated temperatures, in the presence of humidity, promoted heavy tin oxide formation which led to solderability loss. In contrast, thin azole films were shown to be more robust to humidity exposure; however, upon heating in the presence of oxygen, they decomposed and led to severe solderability degradation. Evaluations of lead‐free solder pastes for surface mount assembly applications indicated that immersion tin significantly improved the spreading of Sn:Ag and Sn:Bi alloys compared with azole surface finishes.

The purpose of this paper was to prepare a hybrid organic/inorganic coating with interesting barrier properties against the corrosion of plain carbon steel sheets in 3.5 per cent NaCl solution. The search for replacing chromates in protective coatings has led to the development of hybrid sol-gel anticorrosive coatings. Appropriate functionalization can dramatically enhance the chemical durability and mechanical strength of these coatings.

To prepare the targeted coating, 1,2-epoxybutane (EB) was mixed with 2 to 4 per cent aminoethylaminopropyl-methylsiloxane dimethylsiloxane (APDMS) copolymer and 1,6-diaminohexane. The above coating (EBAC) has been further mixed with three different corrosion inhibitors “Moly-white® 101-ED, Heucophos Zapp® and cerium ammonium nitrate”, yielding the coatings EBAC-M, EBAC-Z and EBAC-Ce, respectively. The corrosion characteristics of all coatings on the steel panels immersed in 3.5 per cent NaCl solution were obtained using different electrochemical methods such as electrochemical impedance spectroscopic and Tafel polarization measurements.

The newly prepared coatings showed interesting protection properties for protecting the steel substrate against corrosion in chloride-containing media.

The results provide a good approach for the modification of polydimethylsiloxane coatings using a simple organic modifier.

The purpose of this work was to prepare a hybrid organic/inorganic coating with interesting barrier properties against the corrosion of plain carbon steel sheets in 3.5 per cent NaCl solution. The search for replacing chromates in protective coatings has led to the development of hybrid sol-gel anticorrosive coatings. Appropriate functionalization can dramatically enhance the chemical durability and mechanical strength of these coatings.

To prepare the targeted coating, 1,2-epoxybutane (EB) was mixed with 2-4 per cent aminoethylaminopropyl-methylsiloxane dimethylsiloxane copolymer and 1,6-diaminohexane. The above coating (EBAC) was further mixed with three different corrosion inhibitors “Moly-white® 101-ED, Hfucophos Zapp®” and Cerium Ammonium Nitrate, yielding the coatings (EBAC-M), (EBAC-Z) and (EABC-Ce), respectively. The corrosion characteristics of all coatings on carbon steel panels immersed in 3.5 per cent NaCl solution were obtained using different electrochemical methods such as electrochemical impedance spectroscopic and Tafel polarization measurements.

The newly prepared coatings showed interesting properties for protecting the steel substrate against corrosion in chloride containing media.

The results provide a good approach for the modification of polydimethylsiloxane coatings using a simple organic modifier.

The purpose of this paper is to study properties of intumescent coatings based on a silicone‐epoxy hybrid resin (with an aminosilane as hardener). In the first part of this study, fire‐resistance behaviour of the intumescent coating based on silicone‐epoxy resin containing intumescent additives is evaluated. The second part assesses the effect of mineral fibres on fire‐resistant properties of intumescent coatings based on the silicone‐epoxy resin.

Thermal degradation and char formation of coatings were investigated by Thermogravimetric analyses, X‐ray diffraction and X‐ray fluorescence and infrared spectroscopy (FTIR). The salt spray corrosion test was applied to study the resistance of intumescent coatings. Anticorrosion and fire‐resistant properties after one, three and seven days of exposure were evaluated.

It was shown that a silicone‐epoxy hybrid resin is suitable for applications in the field of intumescent coatings. Intumescent coatings based on this resin form a thermally stable thin ceramic‐like layer, which improves the thermal insulation properties of the char. Mineral fibres reinforced the char structure and thus improved fire‐resistant properties of intumescent coating before as well as after the salt spray test. Mineral fibres also improved anticorrosion properties.

This paper discusses only the effect of mineral fibres on properties of intumescent coatings.

A silicone‐epoxy hybrid resin has not previously been used in intumescent coatings. This type of intumescent coating can be used as an effective passive fire protection system for steel constructions.