Work

Multifunctional multilayer coatings: Enhancing durability through self-healing mechanisms activated via Joule effect

Year: 2024

Type: article

Abstract: A multilayer coating with multifunctional capabilities has been developed, consisting of an inner self-heating layer via carbon nanotube (CNT) addition into an epoxy resin with two different surface pre-treatments (non-treated and grit blasted), and an outer self-healing layer based on an epoxy/polycaprolactone (PCL) blend and an epoxy/2-aminophenyl disulfide (2-AFD). The analysis of the glass transition temperature (T g ) in the outer layer showed no significant differences between PCL and AFD-based mixtures, with values around 135 °C. The results of the electrical conductivity tests demonstrated that the grit blasting surface pre-treatment on the inner layer had no influence on the electrical conductivity. Indeed, all systems successfully reached the temperature to activate the vitrimeric behavior of the outer layer via resistive heating at voltages within the range of 80 to 140 V. Moreover, a novel self-healing test was conducted and recorded in an environmental scanning electron microscope (ESEM) chamber to establish the self-healing time required to achieve a high crack recovery efficiency. Finally, the results of the self-healing tests under convective and Joule heating show comparable healing efficiencies, exceeding 82 % in all study conditions showing a good capability for an autonomous repair and increasing the accessibility in difficult conditions such as offshore wind energy. • Multilayer coatings with an inner self-heating layer and an outer self-healing layer have been developed. • Two different self-healing layers, one based on an epoxy/PCL-blend and other on an epoxy/AFD vitrimer, were characterized. • The thermoelectrical behaviour demonstrated effective heat transfer from the inner to the outer layer. • A self-healing test was conducted and recorded in an environmental scanning electron microscope (ESEM) chamber. • The self-healing efficiency values were higher when applying resistive heating (91%) compared to convective heating (86%).

Source: Progress in Organic Coatings

DOI: 10.1016/j.porgcoat.2024.109018

Authors: Javier Gómez-Sánchez, Xoan Xosé Fernández Sánchez-Romate, Gilberto del Rosario, Silvia González-Prolongo, Alberto Jiménez-Suárez

Institution: Universidad Rey Juan Carlos

Language: English

Topic: Polymer composites and self-healing

Subfield: Polymers and Plastics

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,110

Funders: Comunidad de Madrid, European Commission, Universidad Rey Juan Carlos, Agencia Estatal de Investigación