ORGANOMETALLIC SURFACE-TREATMENT OF PBZT AND PBO ORDERED POLYMER FILMS FOR IMPROVED ADHESION

Poly(bisbenzothiazole) and poly(bisbenzoxazole), (PBZT and PBO, respectively) when used to make ordered polymer films, enable the fabrication of strong, lightweight, thinwalled structures without the limitations of fiber- reinforced composite structures. However, the bonding of these films to adhesive resins is weak due to the chemical inertness of their surfaces. Foster-Miller applied an organometallic surface-treatment (OST) to heat- treated PBZT and PBO films for the purpose of attaching polar carboxylic acid groups that would increase interfacial interaction in ordered polymer film- based composites. Poly(etheretherKetone) (PEEK), thermoplastic and epoxy thermoset adhesive resins were evaluated. OST significantly increased the wettability of PBZT and PBO film surfaces toward water and epoxy resin in comparison to untreated films. PBZT film/PEEK adhesive peel strength increased more than fivefold, with samples exhibiting cohesive failure. However, the absolute value for peel strength was low, a consequence of low interlaminar shear strength within the films themselves.