Reversible Demountable Coating Films Composed of Trifunctional Liquid Anthracene Compounds and Evaluation of Their Adhesive Properties

Technologies that facilitate recycling are attracting considerable interest from the perspective of resource constraints. In the present study, degradable primer films are to facilitate the removal of strongly bonded joints. This film consists of a light-cured trifunctional anthracene compound that thermally decomposes to its original liquid state. To demonstrate its function as a degradable primer film and verify its range of applications, various substrates, such as aluminum alloys, stainless steel, carbon fiber-reinforced plastics, carbon fiber-reinforced thermoplastics, and polyetheretherketone, are bonded through the primer film using a two-component epoxy adhesive. All the single-lap specimens exhibit strengths above 10 MPa, which is sufficient, or base material fracture. When adhesive bonding specimens prepared using the same procedure are heated at 180 °C to transform the coating film to a liquid state, the bond strength is significantly reduced. The primer film is expected to exhibit long-term stability of more than one year at ≈60 °C.