To evaluate the degradation of silicone based coatings that protect the mild steel surfaces from corrosion in high temperature atmospheres, the coatings were exposed to muffle…
Abstract
To evaluate the degradation of silicone based coatings that protect the mild steel surfaces from corrosion in high temperature atmospheres, the coatings were exposed to muffle furnace for heating ‐ cooling cycle (as per ASTM specification D 2485) up to 700°C. The ability of the paint film to withstand the temperature is related to its resistance as well as microcracks. These factors are very useful in precisely quantifying the degree of deterioration of the protective film. In the present work, two types of silicone based paints (silicone‐titanate, rhodorsil silicone) were prepared and the surface degradation of these coatings were studied by EIS technique and SEM with EDAX analysis. The chemical resistance properties were also analyzed.
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L. Mathivanan and S. Radhakrishna
This article presents a study of the major corrosion problems of steel structures in rubber and palm oil mill industries in Malaysia. Such structures, improperly coated with…
Abstract
This article presents a study of the major corrosion problems of steel structures in rubber and palm oil mill industries in Malaysia. Such structures, improperly coated with protective treatment (commercial coatings) were easily damaged by corrosion due to the environment within a month’s time. In order to prevent these types of corrosion problems, the epoxy‐silicone resin based paints were developed. The performance of the coatings were evaluated. These studies confirm the fact that the epoxy‐silicone coatings are effectively useful for protection of steel structures in these industries for considerably longer times.
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Silicone resin based protective coatings are generally used for high temperature applications. In this work, anti‐corrosive and heat resistant properties of titanium dioxide…
Abstract
Silicone resin based protective coatings are generally used for high temperature applications. In this work, anti‐corrosive and heat resistant properties of titanium dioxide, mica, zirconium oxide and quartz combination pigments with silicone resin as carrier vehicle in primer and top coat for mild steel surface have been evaluated. Promising results were obtained, showing that the ceramic pigments (zirconium oxide and quartz) impart heat‐resistance protection for steel substrate up to 370°. Electro‐chemical impedance spectroscopy, immersion studies and salt spray test results show good corrosion protection for the steel surface.
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L. Mathivanan and S. Radhakrishna
Describes the preparation and properties of heat‐resistant paints based on an epoxy blended with rhodorsil silicone resin. Studies the heat‐resistant properties as per ASTM…
Abstract
Describes the preparation and properties of heat‐resistant paints based on an epoxy blended with rhodorsil silicone resin. Studies the heat‐resistant properties as per ASTM standard (D 2485‐91). Also determines the properties of the liquid paint and coated metal panels. Assesses the thermal degradation of the coating both by electrochemical (potential vs time and EIS) and structural (SEM) means. Results reveal that the coating is stable up to 200°C on a mild steel surface and degradation takes place only beyond this temperature. Discusses the failure mechanism of the above coating in light of the experiment’s results.
K.W. Chew, A.H. Yahaya and A.K. Arof
The physical properties of two types of silicone resin were examined. The resin was coated on mild steel panels and allowed to cure for one week. The resin‐coated panels were…
Abstract
The physical properties of two types of silicone resin were examined. The resin was coated on mild steel panels and allowed to cure for one week. The resin‐coated panels were heated according to ASTM specification D 2485. The thermal stability of the resin coatings was examined by electrochemical impedance spectroscopy (EIS) technique and thermogravimetric analyses (TGA). The chemical resistance property of the resin coatings was also studied.
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B. Vengadaesvaran, S. Ramis Rau, Ramesh Kasi and A.K. Arof
The purpose of this paper is to investigate the heat resistance properties of silicone‐acrylic hybrid system on cold rolled mild steel panel.
Abstract
Purpose
The purpose of this paper is to investigate the heat resistance properties of silicone‐acrylic hybrid system on cold rolled mild steel panel.
Design/methodology/approach
The presence of Si−C bonds in hydroxyl functional solid phenyl‐methyl silicone should be able to improve heat resistance properties of silicone‐acrylic polyol coating. Different weight ratios of silicone resin and acrylic polyol resins were blended in order to obtain the composition for optimum thermal properties. Thermal stability of silicone based protective coatings has been investigated by means of potential time measurement (PTM) and electrochemical impedance spectroscopy (EIS) techniques.
Findings
The blending of silicone intermediate resin with acrylic polyol resins. The coating consisting of 30 per cent silicone resin and 70 per cent acrylic resin showed significant improvement of heat resistivity compared to pure acrylic polyol resins on cold roll mild steel panels. This study demonstrates an interesting correlation between PTM and EIS studies.
Research limitations/implications
Findings may be useful in the development of heat resistant paints.
Practical implications
The blending method provides a simple and practical solution to improve the heat resistance properties of acrylic polyol resins.
Originality/value
Durability and functionality of the coating, critically depend on the strength and adhesion properties of the materials. This may be a useful source of information for the development of organic‐inorganic coatings.
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K. Ramesh, Z. Osman, A.K. Arof, B. Vengadaeswaran and W.J. Basirun
Silicone and polyester resins have been prepared at various compositions with the purpose of determining the best performing binder system. The coating materials that have been…
Abstract
Purpose
Silicone and polyester resins have been prepared at various compositions with the purpose of determining the best performing binder system. The coating materials that have been developed have been analysed and evaluated for their protection ability.
Design/methodology/approach
Silicone and polyester resins have been prepared at various compositions to identify best performing binder system. To evaluate the properties, different analytical methods have been employed. Fourier transform infrared spectroscopy has been utilised to study the chemical changes when the polymers were mixed together. Corrosion resistance has been tested through potential time measurement test using NaCl solution. The surface morphology has been evaluated using scanning electron microscopy/energy dispersive X‐ray (EDX) analysis.
Findings
There is a change in intensity of the peaks and shift in the peak values of the functional groups observed. Scanning electron microscopy graphs show the uniform surface morphology of the systems developed. From the EDX analysis, the composition of the coating material has been found. The results showed that the coatings could protect the substrate for 30 days of immersion in 3 per cent NaCl electrolyte solution.
Originality/value
The paper provides an analysis of coatings containing silicone‐polyester resins.
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B. Vengadaesvaran, S.R. Rau, K. Ramesh, R. Puteh and A.K. Arof
The paper's aim is to investigate improvement of strength and adhesion of silicone‐acrylic hybrid systems.
Abstract
Purpose
The paper's aim is to investigate improvement of strength and adhesion of silicone‐acrylic hybrid systems.
Design/methodology/approach
The presence of Si‐C bonds in phenyl silicone should be able to improve strength, adhesion and thermal properties of phenyl silicone‐acrylic polyol coating. Different weight ratios of phenyl silicone and acrylic polyol resins were blended in order to obtain the composition for optimum strength, adhesion and thermal properties. Strength was evaluated using an impact resistance tester. Coating adhesion was studied by measuring the contact angle and performing cross hatch cutting. The thermal properties were studied using differential scanning calorimetry.
Findings
Blending phenyl silicone intermediate resin with acrylic polyol resin showed significant improvement in strength and adhesion properties compared to pure acrylic polyol resin. This paper shows that the composition of such coatings influences the glass transition temperature (Tg), which in turn affects the strength and adhesion properties of the coatings. The coating consisting of 30 per cent silicone resin and 70 per cent acrylic resin showed good adhesion and impact resistance properties on cold roll mild steel panels.
Research limitations/implications
Findings may be useful in the development of heat resistant and anti‐corrosion paints.
Practical implications
The blending method provides a simple and practical solution to improve the strength and adhesion properties of acrylic polyol resins.
Originality/value
Durability and functionality of the coating critically depend on the strength and adhesion properties of the materials. This may be a useful source of information for the development of organic‐inorganic coatings.
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Abstract
Purpose
Corrosion protection is one of the important performance properties of organic coatings. The purpose of this paper is to develop a paint system for the protection of steel substrates from corrosion at high temperature atmospheres using silicone resin blend materials.
Design/methodology/approach
An anti‐corrosion paint system for high temperature atmosphere has been developed using silicone polyester resins. Silicone resin has been chosen due to its good resistance for corrosion in all kinds of environments. The paint system was prepared from the best performing binder system with the addition of inorganic pigments. Heat stability was studied according to ASTM D2485 standards. Adhesion, impact resistance, film formation, thermal stability and electrochemical properties of the prepared coatings were evaluated by cross hatch adhesion method, tubular impact testing, scanning electron microscopy, differential scanning calorimetry (DSC), and electrochemical impedance spectroscopy (ELS), respectively.
Findings
The paint system possessed good adhesion properties and had high‐impact resistance. The SEM graphs showed the uniform formation of the film surface. From thermal analyses, the prepared paint system withstood temperatures up to 400°C. The heat‐treated specimen has also been evaluated for corrosion protection by EIS, which showed high resistance after 30 days of immersion in 3 percent NaCl solution.
Originality/value
In this work, an attempt has been made to develop a good paint system using silicone resin and polyester resin blend materials. This research will be useful for the application for high temperature atmosphere and it can give a valuable guidance to the students who are interested in pursuing research in organic coatings.
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M. Dhanalakshmi, M. Selvaraj, S. Syed Azim and P. Jayakrishnan
Recent developments indicate that the polymer coatings used to protect steel structures from corrosive environments are rarely one‐component systems. Polymeric blends used to…
Abstract
Recent developments indicate that the polymer coatings used to protect steel structures from corrosive environments are rarely one‐component systems. Polymeric blends used to protect the structures are a mixture of at least two polymers or copolymers. The heterophase polymer blends are known as polymer‐polymer composites (PPC). The advantages of PPC coatings in comparison to multicoat systems are high thickness per coat, excellent protection and superior layer adhesion. Presents a study in which a poly (epoxy‐chlorinated rubber‐silicone) PPC coating was prepared and its chemical resistance properties in acid, alkali and neutral solutions were studied. Different combinations of these three binders were also prepared in toluene:acetone solvent mixture and the chemical resistance properties of these PPCs were evaluated in comparison with the corresponding multicoat system with the same thickness. Finds that the PPCs show superior properties when compared to multicoat systems. Studies the electrochemical behaviour such as potential, resistance and capacitance of the PPCs and the multicoat systems on steel substrate in sodium chloride solution and finds that the PPCs have higher resistance value than the multicoat systems. Based on the experimental results, concludes that a single coat of PPC can be recommended for protecting the steel structures from chemical and marine environments, instead of using conventional three‐ or four‐coat systems based on the same or different film formers.