Experimental Evaluation of Polyester and Epoxy– Polyester Powder Coatings in Aggressive Media

izvorni znanstveni rad

izvorni znanstveni rad

Experimental Evaluation of Polyester and Epoxy– Polyester Powder Coatings in Aggressive Media

Vrsta prilog u časopisu
Tip izvorni znanstveni rad
Godina 2018
Časopis Coatings
Nadređena publikacija Coatings
Volumen 8
Svesčić 98
Stranice str. 1-12
DOI 10.3390/coatings8030098
EISSN 2079-6412
Status objavljeno

Sažetak

Protective coatings are the most widely used corrosion protection method for construction materials in different environmental conditions. They isolate metals from aggressive media, making the structure more durable. Today, alongside good anti-corrosive properties, coatings need to be safe for the environment and harmless to those who apply them. The high volatile organic compound (VOC) content in conventional solvent-borne coatings presents a huge ecological problem. A solution for indispensable solvent emission reduction is the application of powder coatings. This study evaluates the corrosion performance and surface morphology of polyester and epoxy–polyester powder coatings. Electrochemical impedance spectroscopy (EIS), open circuit potential (OCP) measurement, salt spray chamber and humidity chamber testing followed by adhesion testing were used to investigate the protective properties of powder coatings. Scanning electron microscope (SEM) with energy- dispersive X-ray spectroscopy (EDX) was used to analyse the surface morphology and chemical composition, whereas the microstructure and coating uniformity were determined by optical microscope examination. The research revealed a negative influence of coating surface texture on coating thickness and consequently a lack of barrier and adhesion properties. The epoxy– polyester powder coating showed a better performance than the polyester coating. All tested coatings showed uniform structure.

Ključne riječi

electrostatic spraying ; powder coatings ; corrosion performance ; EIS study ; SEM analysis