Adhesion and corrosion resistance of epoxy primers used in the automotive industry
Abstract
One of the most important factors in corrosion prevention by protective coatings is the loss of adhesion of the coating under environmental influence. Thus, adhesion strength is often used when characterizing protective properties of organic coatings on a metal substrate. In this work, the adhesion of different epoxy primers (pigment-free, zinc-rich and chromate-based) was examined on steel. Both the dry and wet adhesion strengths of organic primers were measured directly by a pull-off standardized procedure, as well as indirectly by the NMP test. The corrosion stability of coated samples was investigated by electrochemical impedance spectroscopy. It was shown that under dry test conditions all the samples showed very good adhesion. However, different trends in adhesion for different primers during exposure to the corrosive agent (3% NaCl solution) were observed. The lowest adhesion values were obtained for chromate-based epoxy primer; however, the change in adhesion of this protective... system during immersion in 3% NaCl solution for 25 days was the smallest of all investigated samples. Electrochemical impedance measurements in 3% NaCl solution confirmed good protective properties of pigmented epoxy primers on steel, i.e., greater values of pore resistance and charge-transfer resistance, and smaller values of coating capacitance and double-layer capacitance, were obtained for these protective systems.
Keywords:
adhesion / steel / epoxy primers / electrochemical impedance spectroscopySource:
Journal of Adhesion Science and Technology, 2007, 21, 9, 819-831Publisher:
- Taylor & Francis Ltd, Abingdon
Funding / projects:
- Elektrohemijske karakteristike oksidnih i polimernih prevlaka na modifikovanim površinama metala (RS-142061)
DOI: 10.1163/156856107781061512
ISSN: 0169-4243
WoS: 000248328100003
Scopus: 2-s2.0-34748918492
Institution/Community
Tehnološko-metalurški fakultetTY - JOUR AU - Bajat, Jelena AU - Dedić, O. PY - 2007 UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1162 AB - One of the most important factors in corrosion prevention by protective coatings is the loss of adhesion of the coating under environmental influence. Thus, adhesion strength is often used when characterizing protective properties of organic coatings on a metal substrate. In this work, the adhesion of different epoxy primers (pigment-free, zinc-rich and chromate-based) was examined on steel. Both the dry and wet adhesion strengths of organic primers were measured directly by a pull-off standardized procedure, as well as indirectly by the NMP test. The corrosion stability of coated samples was investigated by electrochemical impedance spectroscopy. It was shown that under dry test conditions all the samples showed very good adhesion. However, different trends in adhesion for different primers during exposure to the corrosive agent (3% NaCl solution) were observed. The lowest adhesion values were obtained for chromate-based epoxy primer; however, the change in adhesion of this protective system during immersion in 3% NaCl solution for 25 days was the smallest of all investigated samples. Electrochemical impedance measurements in 3% NaCl solution confirmed good protective properties of pigmented epoxy primers on steel, i.e., greater values of pore resistance and charge-transfer resistance, and smaller values of coating capacitance and double-layer capacitance, were obtained for these protective systems. PB - Taylor & Francis Ltd, Abingdon T2 - Journal of Adhesion Science and Technology T1 - Adhesion and corrosion resistance of epoxy primers used in the automotive industry EP - 831 IS - 9 SP - 819 VL - 21 DO - 10.1163/156856107781061512 ER -
@article{ author = "Bajat, Jelena and Dedić, O.", year = "2007", abstract = "One of the most important factors in corrosion prevention by protective coatings is the loss of adhesion of the coating under environmental influence. Thus, adhesion strength is often used when characterizing protective properties of organic coatings on a metal substrate. In this work, the adhesion of different epoxy primers (pigment-free, zinc-rich and chromate-based) was examined on steel. Both the dry and wet adhesion strengths of organic primers were measured directly by a pull-off standardized procedure, as well as indirectly by the NMP test. The corrosion stability of coated samples was investigated by electrochemical impedance spectroscopy. It was shown that under dry test conditions all the samples showed very good adhesion. However, different trends in adhesion for different primers during exposure to the corrosive agent (3% NaCl solution) were observed. The lowest adhesion values were obtained for chromate-based epoxy primer; however, the change in adhesion of this protective system during immersion in 3% NaCl solution for 25 days was the smallest of all investigated samples. Electrochemical impedance measurements in 3% NaCl solution confirmed good protective properties of pigmented epoxy primers on steel, i.e., greater values of pore resistance and charge-transfer resistance, and smaller values of coating capacitance and double-layer capacitance, were obtained for these protective systems.", publisher = "Taylor & Francis Ltd, Abingdon", journal = "Journal of Adhesion Science and Technology", title = "Adhesion and corrosion resistance of epoxy primers used in the automotive industry", pages = "831-819", number = "9", volume = "21", doi = "10.1163/156856107781061512" }
Bajat, J.,& Dedić, O.. (2007). Adhesion and corrosion resistance of epoxy primers used in the automotive industry. in Journal of Adhesion Science and Technology Taylor & Francis Ltd, Abingdon., 21(9), 819-831. https://doi.org/10.1163/156856107781061512
Bajat J, Dedić O. Adhesion and corrosion resistance of epoxy primers used in the automotive industry. in Journal of Adhesion Science and Technology. 2007;21(9):819-831. doi:10.1163/156856107781061512 .
Bajat, Jelena, Dedić, O., "Adhesion and corrosion resistance of epoxy primers used in the automotive industry" in Journal of Adhesion Science and Technology, 21, no. 9 (2007):819-831, https://doi.org/10.1163/156856107781061512 . .