Plasma-treatment of polyetheretherketone (PEEK) for adhesive bonding

Polyetheretherketone (PEEK) has been treated with oxygen-, air-, argon- and ammonia-plasmas, which greatly improve adhesion to an epoxide film adhesive. Treated surfaces can be stored under laboratory conditions for up to 90 days without significant loss of the improved adhesion properties. Contact angle measurements show that the surface energy of PEEK is much increased by plasma-treatment. X-ray photoelectron spectroscopy shows that the plasmas increase the amounts of oxygen and in some cases the amounts of nitrogen, and that new surface groups include -OH and -CO-. Wiping treated surfaces with acetone can reverse the effects of plasma-treatment.