Interfacial coupling between immiscible polymers: Reactive interface between polysulfone and amorphous polyamide

The coupling reaction at the immiscible polymer-polymer interface formed be tween bilayer films composed of amorphous polyamide (aPA) and polysulfone ( PSU) incorporating different functional groups was monitored by X-ray photo electron spectroscopy (XPS). The overall coupling reaction was consistent w ith pseudo-first-order kinetics, and the process was controlled by the reac tion between functional groups situated at the interface. Anhydride groups attached to PSU, both phthalic anhydride and maleic anhydride, showed signi ficantly faster and higher reactivities than epoxide and triazine groups in the reaction with the primary amine end group of aPA. The saturation areal density of the copolymers at the interface, Sigma*, changed depending on t he architecture of the resultant copolymers, which suggested that Sigma* wo uld be determined by the interfacial area occupied by a single copolymer ch ain at saturation.