Improvement of aerospace thermoplastic composite adhesion to coating with dielectric barrier discharge atmospheric pressure plasma surface treatment

Atmospheric pressure plasma with dielectric barrier discharge is used to improve the adhesion of novel composite carbon fiber reinforced low melting poly (aryl ether ketone) (CF/LMPAEK) to aerospace coatings under ambient and gas flow (Ar‐O2). The surface activation is evaluated by contact angle measurement and X‐ray photoelectron spectroscopy (XPS). Different atmospheres are used to prevent aging of the treated surface. The water contact angle is considerably reduced after plasma treatment, and the formation of oxygen and nitrogen polar groups is confirmed by XPS analysis. Plasma treatment improves the adhesion of CF/LMPAEK to the topcoat on the primer coating system to the traditional abrasion treatment level. This effect even is intensified with Ar‐O2 plasma. The topcoat alone presents a higher adherence, which provides a reduced coating usage option. Atmospheric pressure plasma dielectric barrier discharge plasma treatment increases the adhesion of CF/LMPAEK composite to polyurethane coating system up to 200% compared to traditional abrasion pretreatment. Ar‐O2 plasma enhances adherence while the increase in the number of passes has no substantial effect. Considering adhesion characteristics only, plasma treatment suppresses the need for primer allowing direct coating with topcoat