TY - JOUR
T1 - Superabsorbent polymer additives for repeated barrier restoration of damaged powder coatings under wet-dry cycles
T2 - A proof-of-concept
AU - Saini, Vimal
AU - von Tapavicza, Max
AU - Eloo, Christina
AU - Braesch, Katrin
AU - Wack, Holger
AU - Nellesen, Anke
AU - Schmidt, Annette M.
AU - García, Santiago J.
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Superabsorbent polymers (SAPs) are well known for their ability to absorb and hold high water amounts accompanied by a high volume expansion. In this work we show the benefits of this underlying property of SAPs to induce underwater crack closure with subsequent barrier restoration in damaged protective coatings. For the proof of concept, three layer epoxy-polyester (EP) powder coating systems were developed and applied on carbon steel. In these systems the middle EP layer (also called functional layer) contained crosslinked acrylamide/acrylic acid copolymer SAPs in different amounts ranging from 0 to 40 wt%. The capability of the SAPs to close damages and extend barrier and corrosion protection was evaluated by electrochemical impedance spectroscopy (EIS), NaCl aqueous solution immersion test and optical microscopy. It was found that coatings loaded with a 20 wt% SAP led to the best overall corrosion protection for the studied systems. In order to proof the potential use of this extrinsic healing concept for multiple healing events wet-dry cycles on scratched systems were performed and the corrosion performance was followed by EIS. Although not yet optimal, the results show the potential of the concept for multiple healing events under wet-dry conditions.
AB - Superabsorbent polymers (SAPs) are well known for their ability to absorb and hold high water amounts accompanied by a high volume expansion. In this work we show the benefits of this underlying property of SAPs to induce underwater crack closure with subsequent barrier restoration in damaged protective coatings. For the proof of concept, three layer epoxy-polyester (EP) powder coating systems were developed and applied on carbon steel. In these systems the middle EP layer (also called functional layer) contained crosslinked acrylamide/acrylic acid copolymer SAPs in different amounts ranging from 0 to 40 wt%. The capability of the SAPs to close damages and extend barrier and corrosion protection was evaluated by electrochemical impedance spectroscopy (EIS), NaCl aqueous solution immersion test and optical microscopy. It was found that coatings loaded with a 20 wt% SAP led to the best overall corrosion protection for the studied systems. In order to proof the potential use of this extrinsic healing concept for multiple healing events wet-dry cycles on scratched systems were performed and the corrosion performance was followed by EIS. Although not yet optimal, the results show the potential of the concept for multiple healing events under wet-dry conditions.
KW - Corrosion inhibition
KW - Electrochemical impedance spectroscopy
KW - Powder coating
KW - Self-healing
KW - Superabsorbent polymer
UR - http://www.scopus.com/inward/record.url?scp=85047256575&partnerID=8YFLogxK
UR - http://resolver.tudelft.nl/uuid:0ba63143-201d-4e5b-b307-3eb5e4faa1d9
U2 - 10.1016/j.porgcoat.2018.05.019
DO - 10.1016/j.porgcoat.2018.05.019
M3 - Article
AN - SCOPUS:85047256575
SN - 0300-9440
VL - 122
SP - 129
EP - 137
JO - Progress in Organic Coatings
JF - Progress in Organic Coatings
ER -