Fully sustainably sourced and closed-loop recyclable underwater adhesive for on-demand erasable electronic sealing

Abstract

Electronic adhesives have gained widespread applications in flexible electronics, intelligent robots, the automotive industry, and aerospace. However, most adhesives are prepared from petroleum-based raw materials, which present sustainable development challenges such as non-degradability, non-erasability, and non-closed-loop recycling. In this work, we propose a strategy for constructing a fully dynamic covalent adaptive network using a fully sustainable source of epoxy soybean oil and thioctic acid to create a closed-loop recyclable and tough underwater adhesive. The adhesive exhibits tough bonding behavior in water (1.21 MPa), saline water (1.05 MPa), strong acid (1.08 MPa), high humidity–heat (1.19 MPa), and even liquid nitrogen environments (0.90 MPa). More impressively, the tough adhesive could achieve chemical closed-loop recycling of thioctic acid, as well as full degradability under mild conditions. Furthermore, the adhesive is applied to on-demand erasable and durable electronic sealing even in water and at low temperatures, featuring multiple protections, including waterproofing, dustproofing, and impact resistance. The electronic sealing demonstrates a convenient on-demand erasable feature, providing the possibility for electronic maintenance and reducing electronic waste pollution. It is anticipated that the bio-based closed-loop recyclable adhesive will offer promising insights into the development of high-end sustainable electronic materials.