Organic coatings

A nanocomposite is a matrix to which nanoparticles have been added to improve a particular property of the material. The properties of nanocomposites have caused researchers and companies to consider using this material in several fields. The nanoparticles if added to the polymers matrix in the concentration of around .5 to 2%, the properties of the composites like mechanical, physical, electrical, optical shows a dramatic change in their magnitude. The particle size and the concentration of the nano filler is the backbone this change. The particle size <100nm is considered the result oriented in these properties (14). The characteristics of the particle nature are also play a role in properties like electrical, magnetic and optical. Although for mechanical and physical properties the particle sizes are important.

A glycidyl epoxide, adduct of tung oil (ETO) was synthesized using glycidyl methacrylate (GMA). The ETO was characterized by IR, 1 H NMR, 13C NMR, ESI-mass, and GC. The ETO was cross-linked with two different tria-mines (Jeffamines T3000 and T403) at three temperatures using 2,4,6-tris(dimethyl-aminomethyl)phenol as catalyst. The cured coatings were analyzed by IR, differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), gel content, and various coatings tests. The epoxide-amine polymers exhibited thermal stability up to 353 •C with a glass transition up to 174 •C. The amine cured epoxides were obtained with fairly high Tg values and excellent thermal stability. Mechanical performance properties of these films were investigated by pendulum hardness, pencil hardness, crosshatch adhesion, pull off adhesion, impact resistance, reverse resistance and chemical resistance. It has been observed that the epoxide-amine systems cured at 150 •C exhibited the best overall properties in terms of pencil hardness (6 H), pull-off adhesion (3.0-5.0 lb/in 2), crosshatch adhesion (5B), impact resistance (> 40), reverse resistance (> 40), and MEK resistance (95-135).

A thorough understanding of the corrosion thermodynamics and kinetics is first presented. Furthermore, the protective mechanisms of barrier, sacrificial, and inhibitive coatings are outlined. Sol -gel coatings and SNAP coatings are the focus of investigation in this review. In this article, recent developments in the processing stages and functional properties of the finally produced sol-gel-based hybrid coatings will be overviewed. Finally, some of the new and novel advancements in this area developed by different research groups will be discussed.

Titanium dioxide (TiO2) due to its high refractive index, is widely used in paint industry as a white pigment. In order to reduce this high cost of TiO2, a part of TiO2 is generally substituted by some other industrial mineral fillers such as calcite and calcined kaolin; however, this substitution affects the quality of paints in terms of stability, coverage (opacity), brightness (gloss), scrub resistance (film toughness), etc. In the present paper, precipitated calcium carbonate (PCC) was substituted for TiO2 in paint mixture at three different pigment volume concentrations (PVC). It was observed that substitution of TiO2 by PCC depends on PVC value at which there is an optimum PCC amount. The quality of paints produced by PCC along with its rheological properties was evaluated based on standard features in both wet and dry paints such as viscosity, density, opacity and gloss values. Addition of PCC increases the opacity to a certain point. Similarly, scrub resistance and viscosity increases with the addition of PCC at all PVCs, however, viscosity is not as much critical for the paint production. On the other hand, there is no any systematic effect of PCC on gloss value of the paint. This study overall demonstrates that PCC can be successfully used to substitute TiO2 only with a careful adjustment of PVC and other extenders used in the paint formulation.

For decades we have hearing that the chemical industry and there also the coating industry, need to break free from its dependency on oil because there are finite resources. Renewable raw materials are constantly under discussion. The paint and coatings industry are focused on innovation and being “green”. Green means a smaller carbon footprint, low VOC content, high renewable content and green processes. The use of renewable ingredients to reduce the carbon footprint, eliminating the use of hazardous materials, introducing biorenewables, incorporating recycled materials, lowering VOC emissions, decreasing energy consumption and reducing waste, while proving it can all be accomplished cost-effectively to become more environmentally responsible. The reduction of environmental damage done by coatings sometimes begins before manufacturing even starts. Research into the carbon footprint of coating materials, or the overall amount of climate-affecting carbon dioxide produced in their manufacture, application, transport and disposal, shows that some coatings simply use fewer resources throughout their life cycles. This paper discusses advances in the use of renewable resources in formulations for various types of coatings. The developments in the application of green and efficient technologies in coating systems are discussed here.

Authors systematize the published results of the work in the field of non-isocyanate polyurethanes (NIPUs).
The main attention is paid to substitution of conventional polyurethanes cured at ambient temperatures to NIPUs based on the reaction of cyclic carbonates and amines. Such materials are used mainly in the mass-production of paints, floorings and foam. Sustainable routes and other new ways of NIPU synthesize are described. Also data of hybrid compositions (HNIPUs) are provided.

Constituye la primera parte de un manual para la Industria de Pinturas. En este primer volumen tratamos de las materias primas a emplear, de la producción de pinturas y de los ensayos tanto sobre materias primas como de las pinturas.
En un próximo volumen estará dedicado a los diferentes sectores de empleo de las pinturas así como los diferentes equipos de aplicación y secado. También se trataran los temas relacionados con seguridad, medio ambiente y legislación. También el Control de Calidad y la economía de los procesos. Defectos que se pueden presentar y algunas industrias especiales (Automoción, etc.).

Recently, many efforts have been made to find environmentally friendly substitutes for carcinogen Cr 6+ in the pretreatments of metal substrates. Silane films are one of the important candidates for this purpose. The use of silane films on metallic substrates provides corrosion protection as a result of excellent adhesion and good barrier properties. Their corrosion protection can be improved by adding suitable dopants. There are various methods for applying these films on the metal substrates (sol-gel dip coatings and electrodeposited coating). In this review, several main researches in the field of silane films have been indicated and their results have been analyzed.

A capacitance model for the estimation of water uptake in polymeric coatings is presented.
The model is based upon a linear combination of the individual capacitances of the polymeric
phase, the water and the air contained in the coating. Experimental comparison of the model
with gravimetric data has revealed an improvement with respect to the classical equations.

Corrosion protection of bronze, a metal alloy which is commonly used in decorative architectural elements and for statuary, is a challenge particularly as new and previously untested water-borne coatings are supplanting traditionally used solvent based polymers as protective coatings. Studying film formation of coatings to better prevent corrosion of culturally significant works is an important problem in the field of conservation science. This work aims to further understanding of differences between films formed from water-borne lattices versus solvent based polymeric coatings on bronze substrates using electrochemical impedance spectroscopy and gravimetric analysis to investigate the changes of coatings as they formed solid films. Using equivalent electric circuit models, electrochemical snapshots of the developing films were produced. Those models established time points for the transitions between theoretical stages of the nascent films and allowed for a comparison between two major classes of coating types (using the water-borne Rhoplex TM WL-81 and the solvent based Paraloid TM B-44). Electrochemical analysis showed that diffusion occurs during early stages of film formation of both coating types. The prolonged coalescence of coatings produced from the water-borne latex was found to leave those films susceptible to water sorption. Annealing films as a means to drive out remaining hydrophilic additives and to facilitate film formation was investigated.

Fluorinated polyurethane dispersions (FPUDs) were synthesized using HDI isocyanurate, polyester polyol and DMPA with varying concentrations of trifluoro ethanol (TFE) in the range of 0-9 wt%. Further FPUDs were characterized by FT-IR and 1 H NMR for structural elucidation. Effects of trifluoro ethanol on the dispersion were evaluated by particle size analyzer. It was observed that with increase in TFE, particle size increases. Topography and contact angle were studied by atomic force microscopy (AFM) and goniome-ter, respectively. To gain more insight into the formation of roughness, power spectral density (PSD) analysis was carried out. It was found that with increase in TFE content, surface roughness increases due to migration of fluorinating agent on the coating substrate and consequently water repellency increases. Nano indentation of coating revealed that fluorinated coating possesses less stiffness and elastic modulus, due to the presence of fluorine on the coating. Further, coatings were analyzed for thermal properties by thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) which shows the enhancement in thermal stability and glass transition temperature with increase in TFE content. Anti-graffiti test was carried out which showed improved resistance with increasing fluorine content.

In this study the anticorrosion performance of a two components water-based epoxy coating system is improved by using the nanopolyaniline (nanoPAni) particles. The purchased nanopolyaniline which was dispersed in water was mixed mechanically with the water-based polyamidoamine hardener of the epoxy system using ultrasonic homogenizer. Average particle size of the polyaniline in hardener was determined using dynamic light scattering technique (DLS). Results revealed that the particles were in the range of 50-57 nm. After combining the prepared sample with the DGEBA epoxy resin, finished coating was applied on steel substrates. Anticorrosion performance and adhesion properties of coating which contained nanoPAni were compared to the model water-based epoxy coating with the help of salt spray and adhesion tests. Results showed that anticorrosive performance of the model water-based epoxy system improved dramatically by adding only 0.02 wt.% nanoPAni. However in contrast to model coating, adherence of PAni-epoxy coating to steel plates was remained constant after their exposure to the corrosive media. Fig. 3. SEM photograph of surface transection of steel plates (a) before and (b) after exposure to salt spray medium for 1000 h.

Our research has led to the development of single component polymeric penetrant which can be applied with or without surface preparation over clean or lightly corroded steel/aluminum (no sand blasting or chemical treatment needed). Coating contains unique Nano-sized reactive materials which first penetrate the rust and scale to its morphological depth and then migrate to the non-corroded metal surface. Once the particles penetrate to metal surface, they polymerize and completely encapsulate and arrest the rust by forming a highly crosslinked network that is impervious to moisture and corrosive salts. The coating forms a long-lasting chemical and physical bond with base metal. Results over cleaned pretreated steel surfaces can exceed 10,000-hour salt spray with no blisters or scribe creep when top coated. Many coatings for use in refinery or off shore applications are comprised of three layers, which may include 75 to 150 microns of a zinc rich primer, 25 to 35 microns of an epoxy primer and 60 to 100 microns of a two-component urethane topcoat. The new innovative technology described herein provides a significant benefit in terms of 1) improved performance 2) elimination of the epoxy primer coat and 3) material and labor cost savings as the primer is applied at 100 to 125 microns and the topcoat at 75 to 100 microns.

The three-dimensional Scanning Vibrating Electrode Technique (3D-SVET) has been used to investigate the effects of forming and UV irradiation on model plasticized PVC coatings and specifically the influence on the barrier properties of the coating. In addition, an industrially produced coating that had undergone outdoor exposure (for approximately seventeen years) was analyzed as a comparison. Results from the investigation show a significant correlation between the corrosion observed on the model samples when compared to the naturally weathered material.

In this article, 3-Hexyl thiophene (3HTh) monomer was electrocoated
on carbon fiber micro electrode (CFME) to study electrochemical
impedance spectroscopic (EIS) analysis. Poly(3HTh)/
CFME is characterized by Cyclic voltammetry (CV), Fourier transform
infrared reflectance-attenuated total reflection spectroscopy
(FTIR-ATR), Scanning electron microscopy-Energy Dispersive
X-ray analysis (SEM-EDX), and electrochemical impedance spectroscopy
(EIS). The effects of different monomer concentrations
(0.5, 1.0 and 1.5mM) on polymer were reported in 0.1M tetraethyl
ammonium tetrafluoroborate (TEABF4)/acetonitrile (ACN) solution.
The highest low frequency capacitance (CLF¼1.394 mF cm
2) was
obtained for [3HTh]0¼0.5mM. The equivalent circuit model of
R(QR(CR)(RW))(CR) was examined for polymer/electrolyte system.

""(EN)Compositions are disclosed containing a solvated viscoelastic polymeric gel diluted into an ionically conductive aqueous solution which can be usefully applied to any surface that is hydrophobic to act, for example, as an antifogging coating with minimal optical distortion and excellent transparency. The compositions can also be used as lubricious agents on medical implants, shunts, and surgical supplies to minimize tissue trauma, to maximize bio-compatibility, and to increase healing by enhancing better irrigation and flow in adjacent tissue.
(FR)L'invention porte sur des compositions contenant un gel polymère viscoélastique solvaté, dilué dans une solution aqueuse ioniquement conductrice qui peut être utilement appliquée sur toute surface qui est hydrophobe, pour servir, par exemple, de revêtement antibuée avec une distorsion optique minimale et une excellente transparence. Les compositions peuvent également être utilisées en tant qu'agents lubrifiants sur des implants médicaux, des dérivations, et des fournitures chirurgicales, pour rendre minimal le traumatisme tissulaire, pour rendre maximale la biocompatibilité et pour augmenter la cicatrisation par une meilleure irrigation et une amélioration de la circulation dans le tissu adjacent""

Dye-sensitised solar cells (DSC's) have widely been investigated over last two decades due to their attractive photovoltaic performance and a certain possibility of industrialization. Both the metallic as well as non-metallic substrates can be used to fabricate DSC's with variable efficiencies. It has been reported so far that DSC's based on transparent conducting oxide (TCO) coated glass are over 10% efficient whereas photoconversion efficiency of titanium metal based DSC's is limited to 7% at present. However, DSC's fabricated on metallic substrates have significant industrial importance as they are electrically conducting, thermally stable and flexible in nature which are essential requirements for roll-to-roll DSC production. Therefore, from industrial perspective titanium metal is said to be the ideal candidate for DSC fabrication due its extraordinary physical as well as corrosion resistant properties. Unfortunately it is costlier than traditional ferrous alloys which are highly reactive with the aggressive I-/I3- redox electrolyte. This problem has been tackled in this paper by presenting a novel corrosion resistant electrically conducting functional coating for such ferrous alloys so that DSC fabrication on them will become possible at lower cost.
This functional coating was developed by incorporating electrically conducting titanium nitride (TiN) particles into polyimide (PI) matrix system. The cured TiN/PI coating displayed uniform distribution of micron sized TiN particles into PI matrix giving rise to electrically conducting composite coating capable of withstanding high temperatures (up to 500oC) while maintaining excellent dimensional stability and lower electrical resistivity values as equivalent to the transparent conducting oxides. This facilitates titania sintering on the coating without losing its integrity. In addition, both TiN and polyimide are corrosion resistant in nature hence the coating protects the underlying substrate from the aggressive I-/I3- electrolyte while maintaining its electrical conductivity.
DSC's fabricated using such a coating on architectural steel substrates exhibit similar photovoltaic characteristics to Ti metal based cells under the same experimental environment.
Moreover, such coating can also be used to fabricate TCO less counter electrodes for DSC’s. Corrosion prone metals and non-conducting soda glass substrates can be coated with this coating for their application as low cost counter electrodes for forward illuminated dye-sensitised solar cells. A comparative study based on photovoltaic performances of platinised TCO coated glass and TiN/PI based counter electrodes has also been included in this paper.

In this study the anticorrosion performance of a two components water-based epoxy coating system is improved by using the nanopolyaniline (nanoPAni) particles. The purchased nanopolyaniline which was dispersed in water was mixed mechanically with the water-based polyamidoamine hardener of the epoxy system using ultrasonic homogenizer. Average particle size of the polyaniline in hardener was determined using dynamic light scattering technique (DLS). Results revealed that the particles were in the range of 50-57 nm. After combining the prepared sample with the DGEBA epoxy resin, finished coating was applied on steel substrates. Anticorrosion performance and adhesion properties of coating which contained nanoPAni were compared to the model water-based epoxy coating with the help of salt spray and adhesion tests. Results showed that anticorrosive performance of the model water-based epoxy system improved dramatically by adding only 0.02 wt.% nanoPAni. However in contrast to model coating, adherence of PAni-epoxy coating to steel plates was remained constant after their exposure to the corrosive media. Fig. 3. SEM photograph of surface transection of steel plates (a) before and (b) after exposure to salt spray medium for 1000 h.

Impedance measurements allow early evaluation of the protective properties of paint coatings and linings. They are applied for comparison of coatings, monitoring of their properties and determination of the protection mechanism. This methodology is being used more and more frequently in laboratory investigations. On site studies are more difficult due to the need of using complex computer controlled apparatus and

The goal of this investigation is to obtain alkyd resins using recycled poly (ethylene terephthalate), PET, and different vegetable oils. Glycolysis of PET waste using pentaerytheritol (PEr) was used to produce suitable hydroxyl oligomers, GPEr, for alkyd resin. The glycolysis was carried out in the presence of manganese acetate as a catalyst and m-cresol as a solvent at 220 o C. Alkyd resins were prepared using phthalic anhydride, PET waste, glycerin, sunflower oil or linseed oil and ethylene glycol to produce PET-based alkyd resin. GPEr was used instead of PRT waste to produce the second type of alkyd resin based on GPEr. The reactions were carried out in the presence of butylhydroxytin oxide as a catalyst to prepare alkyd resins. The curing characteristics of the resins produced were investigated. Corrosion resistivity based on salt spray and cathodic disbondment were evaluated for the cured alkyd as organic coating for carbon steel.

The goal of this investigation is to obtain alkyd resins using recycled poly (ethylene terephthalate), PET, and different vegetable oils. Glycolysis of PET waste using pentaerytheritol (PEr) was used to produce suitable hydroxyl oligomers, GPEr, for alkyd resin. The glycolysis was carried out in the presence of manganese acetate as a catalyst and m-cresol as a solvent at 220 o C. Alkyd resins were prepared using phthalic anhydride, PET waste, glycerin, sunflower oil or linseed oil and ethylene glycol to produce PET-based alkyd resin. GPEr was used instead of PRT waste to produce the second type of alkyd resin based on GPEr. The reactions were carried out in the presence of butylhydroxytin oxide as a catalyst to prepare alkyd resins. The curing characteristics of the resins produced were investigated. Corrosion resistivity based on salt spray and cathodic disbondment were evaluated for the cured alkyd as organic coating for carbon steel.

Electrochemical techniques are mainly known in the field of cultural heritage conservation as a tool for the elimination of corrosion layers or the removal of chlorides. However, these techniques are also a valuable tool for assessing the anti-corrosive efficiency of protective coatings. The aim of this study was to evaluate the performance of different coatings for their use in metallic heritage conservation using polarization resistance (R p) and electrochemical impedance spectroscopy (EIS). Carbon steel samples were prepared to simulate the surface composition and morphology of historic steel artefacts, and coated by a conservator-restorer following the common practices in conservation treatments. Three commercial organic coatings have been studied: a microcrystalline wax (Renaissance TM) and a methyl acrylate/ethyl methacrylate copolymer resin (Paraloid TM B-72) dissolved in acetone-both them commonly used in conservation and restoration treatments-and a ethylene copolymer wax emulsion in water (Poligen TM ES-91009), that has not been used so far for this purposes. Four commercial corrosion inhibitor additives were added to the Paraloid TM B-72 resin and Poligen TM ES-91009 wax. The additives were commercial preparations with the following known active components: a blend of triazoles (M435), an ammonium salt of tricarboxylic acid (M370), a calcium sulphonate (M109), and a bis-oxazoline (Alkaterge-T TM). R p and EIS results showed that the best protection of the steel specimens was afforded by Poligen TM ES-91009 when applied in thick layers. None of the additives have shown a clear improvement of the protection properties of the coatings, and one of them impaired the barrier effect of the coating.

A thorough understanding of the corrosion thermodynamics and kinetics is first presented. Furthermore, the protective mechanisms of barrier, sacrificial, and inhibitive coatings are outlined. Sol –gel coatings and SNAP coatings are the focus of investigation in this review. In this article, recent developments in the processing stages and functional properties of the finally produced sol-gel-based hybrid coatings will be overviewed. Finally, some of the new and novel advancements in this area developed by different research groups will be discussed.