FEICA 2023 Conference and EXPO
Tarragona, Spain, 13-15 September 2023

Presentation Abstract

Strategies for eco-designing disbonding on demand epoxy adhesives

The adhesives industry has always been on the pursuit of stronger and more durable adhesives to face the most demanding joint problem. However, the current climate emergency demands a step forward in this path, to not only design a high-performance adhesive, but also one that allows circularity of the assembly.

Epoxy adhesives have the lead when thinking in high performance structural adhesives in terms of mechanical properties, chemical resistance and high adhesion. This privileged position, however, make the circularity challenge especially difficult. This work clarifies the strategies to address this challenge and proposes the solutions that can be implemented to design disbonding-on-demand epoxy adhesives.

The first proposal is a physical mechanism. With the additivation of Thermo-expandable microspheres (TEMs) in the adhesive matrix that have insignificant impact to mechanical properties, structural adhesives can be disbonded with a thermal trigger at feasible temperatures, typically 50ºC over their Tg.

Secondly, a chemical mechanism is suggested. Here two approaches can be considered: when a classic epoxy-amine system is to be dismantled, a novel Zinc salt catalyzed solvolysis is a successful option. One step forward is to design formulations with cleavable hardeners especially meant to be broken in milder conditions.

Co-author(s): Javier Gómez, Jordi Arbusà, Francisco Ripoll, Jaime Ferrer-Dalmau, Núria Agulló, Salvador Borrós