Metal/polymer interactions

Abstract

Polyimides by nature are highly resistive materials which exhibit exceptional thermal and chemical stabilities. Yet, there are a number of instances in which a polymeric material displaying low resistance and featuring similar physical, chemical, and thermal characteristics as polyimide would be desirable. Toward this goal, multilayered polyimide composite films have been produced through the homogeneous incorporation of copper salts and complexes into poly(amide acid) followed by thermal processing. In this way, highly anisotropic copper containing composite films have been obtained which feature a surface or near-surface layer of copper metal or copper oxide as the conductive medium.

The surface resistivity of the composites is lowered up to ten orders of magnitude relative to unmodified polyimide films. However, in many cases, the discontinuity of the copper containing layer limits the attainment of near-theoretical resistivity. Hence, evaluation of the composites by a variety of analytical techniques have been used to develop structure-process-property relationships in order to optimize the electrical properties of these materials.

The surface treatment of polymeric materials by glow discharge is known to improve their adhesive strength when in contact with a large number of other substances, be they polymeric, metallic, or ceramic in nature. Many efforts have been made to characterize this phenomenon, however in most instances, details concerning the interfacial structure and adhesion mechanism are not fully understood.

The second part of this Dissertation describes the structure and chemistry occurring in the interfacial region between sputter-coated titanium metal, and both plasma pretreated and nonpretreated polyethylene terephthalate (PET) film. The effect of plasma pretreatment on nonmetallized PET is discussed as well. Upon application of a gaseous plasma, titanium/polyester adhesion increases dramatically following metallization compared to the nonpretreated analog. In order to relate this phenomenon to a physical and/or chemical change X-ray photoelectron spectroscopy, Auger electron spectroscopy, transmission electron microscopy, as well as, surface Fourier transform infrared spectrometry have been used to characterize both the surface and interfacial regions of these films.