Polyphenyletherketone and polyphenylethersulfone adhesives for metal-to-metal joints

Two major factors play an important part in improving adhesive bonding in crystalline polyphenyletherketone ( pek) and amorphous polyphenylethersulfone ( pes) polymer-to-metal joint systems: (1) the mechanical strength of reaction product layers formed at polymer/metal interfaces is greater than that of the polymer itself; and (2) the extent of mechanically weak Fe 2O 3 layers on interfacial metal surfaces, which should be minimized to avoid the undesirable cohesive failure mode through these layers. As a result, the most promising failure mechanism for good bond performance was the mixed cohesive failure modes in which separation occurred in both the polymer and adhesive layers at the polymer/metal interfaces.