Epoxy powder coatings containing polyaniline for enhanced corrosion protection

TitleEpoxy powder coatings containing polyaniline for enhanced corrosion protection
Publication TypeJournal Article
Year of Publication2009
AuthorsRadhakrishnan, S, Sonawane, N, Siju, CR
JournalProgress in Organic Coatings
Volume64
Issue4
Pagination383-386
Date PublishedMAR
ISSN0300-9440
KeywordsCorrosion resistance, Epoxy, polyaniline, Powder coating
Abstract

Incorporation of polyaniline (PANI) in epoxy type powder coating formulations has not been attempted earlier. Using specific grade of PANI with low doping, it can be incorporated in epoxy powder coating formulations by twin screw extrusion process. The powder formulations were deposited on steel substrates by electrostatic spray coating at -60 W and baked at 140 degrees C for 20 min. These were extensively tested for corrosion resistance by exposure to hot saline conditions followed by electrochemical impedance spectroscopy and also salt spray testing. PANI incorporated coatings showed no deterioration even after 1400 h of hot (65 degrees C) saline treatment. The coatings intentionally scratched also exhibited self healing property and there was no rust formation even after prolonged exposure to hot saline conditions. These results could be explained on the basis of additional crosslinking due to PANI, as confirmed by DSC results, which gave rise to improved barrier property and self healing was associated with the scavenging of ions by PANI which prevented corrosion of the underlying substrate. (C) 2008 Elsevier B.V. All rights reserved.

DOI10.1016/j.pargcoat.2008.07.024
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)1.862
Divison category: 
Physical and Materials Chemistry