Superabsorbent polymer additives for repeated barrier restoration of damaged powder coatings under wet-dry cycles: A proof-of-concept

Saini, Vimal; von Tapavicza, Max; Eloo, Christina; Braesch, Katrin; Wack, Holger; Nellesen, Anke; Schmidt, Annette M.; Garcia, Santiago J.

doi:10.1016/j.porgcoat.2018.05.019

Superabsorbent polymer additives for repeated barrier restoration of damaged powder coatings under wet-dry cycles

Title

Superabsorbent polymer additives for repeated barrier restoration of damaged powder coatings under wet-dry cycles: A proof-of-concept

Author

Saini, Vimal (Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT; University of Cologne)
von Tapavicza, Max (Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT; University of Cologne)
Eloo, Christina (Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT)
Braesch, Katrin (Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT)
Wack, Holger (Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT)
Nellesen, Anke (Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT)
Schmidt, Annette M. (Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT; University of Cologne)
Garcia, Santiago J. (TU Delft Novel Aerospace Materials)

Date

2018-09-01

Abstract

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.

Subject

Corrosion inhibition
Electrochemical impedance spectroscopy
Powder coating
Self-healing
Superabsorbent polymer

To reference this document use:

http://resolver.tudelft.nl/uuid:0ba63143-201d-4e5b-b307-3eb5e4faa1d9

DOI

https://doi.org/10.1016/j.porgcoat.2018.05.019

Embargo date

2020-05-18

ISSN

0300-9440

Source

Progress in Organic Coatings, 122, 129-137