Polyamic acid interactions with aminopropylsilane surface conditioners on metal

Grazing incidence infrared analysis reveals that metal surfaces of Ag, Al, Cu, Cr, and Al/Cu or Al/Cu/Si alloys interact with APS solutions of natural pH (10.4) to produce passivating siloxane films. These films restrict polyamic acid interaction with metal and amine functionalities, so that covalent attachment of the amic acid to the surface, through the adhesion promoter, does not occur. Instead, imidization appears to proceed in a normal fashion above a siloxane interfacial region which is coordinated to the metal surface by amine‐metal interactions.