Studies on anticorrosion properties of polyaniline-TiO2 blended with acrylic-silicone coating using electrochemical impedance spectroscopy
Abstract
Purpose
The purpose of this paper is to study the performance of coatings for corrosion protection. In this research, different compositions of polyaniline (PANI) were added in a pigmented acrylic polyol-silicone coating. The important performance property is corrosion protection. The coatings must be evaluated under corrosive environment. Electrochemical impedance spectroscopy (EIS) is the suitable method to investigate the effect of the addition of PANI in the binder mixture.
Design/methodology/approach
The coating resistance, coating capacitance, water uptake and the diffusion coefficient of the coatings were tested for each of the sample. These parameters of the coatings were tested for a period of 60 days of exposure of 3.5 weight per cent solution of sodium chloride salt. EIS results will be further verified by immersion test and salt spray test.
Findings
Coating materials developed using 8 and 10 weight per cent of PANI exhibited better coating properties with higher coating resistance for a period 60 days immersion in corrosive environment compared to coatings with lower amount of PANI (2-6 weight per cent). The best coating system obtained the coating resistance value in the range of giga ohms even after the 60th day of exposure. The lowest capacitance value suggested that the coatings have not allowed the electrolyte to permeate to the interface. Water uptake values were found to be in the range of 5 per cent. Salt spray test results showed that the corrosion has initiated at the edges of the scratches only.
Practical implications
The study of the effect of conducting polymers in acrylic polyol/silicone resin hybrid binder will be useful for more exploration in coating science.
Originality/value
The development of protective hybrid coatings using conducting polymer and TiO2 particles is new. The results show high coating resistance values.
Keywords
Acknowledgements
The authors would like to thank University of Malaya for providing research grants to support the project. The research work has been highly supported by UMRG Programme RP025C-14AFR and RG277/14AFR grants. The authors also thank the Centre of Ionics University of Malaya (CIUM) for providing the equipment and instruments that helped them to carry on this research.
Citation
Mohd Jamari, S.K., Kasi, R., Ismail, L., Mat Nor, N.A., Subramanian, R.R., Subramaniam, T.R., Balakrishnan, V. and Mohd Arof, A.K. (2016), "Studies on anticorrosion properties of polyaniline-TiO2 blended with acrylic-silicone coating using electrochemical impedance spectroscopy", Pigment & Resin Technology, Vol. 45 No. 1, pp. 18-23. https://doi.org/10.1108/PRT-02-2014-0016
Publisher
:Emerald Group Publishing Limited
Copyright © 2016, Emerald Group Publishing Limited