Electrochemistry of Aromatic Polyimides

Abstract

Polyimides derived from condensation of pyromellitic dianhydride with various diamines have been shown to be electrochemically active. Films of these materials coated on the surface of solid electrodes, immersed in electrolyte solutions of dipolar aprotie solvents undergo two distinct reversible redox processes, involving addition of one or two electrons per repeat unit. These processes can be carried out completely and stoichiometrically for films as thick as 20 ~m. Spectrophotometric studies and comparison with model compounds lead to the following conclusions: (i) ion permeability, which is a necessary component of the electrochemical charging and discharging processes, is related to solvent swelling and is, in turn, strongly influenced by the physical history of the polymer, (ii) redox activity involves localized molecular electronic states of the pyromellitic diimide group, (iii) there is no evidence for electronic interactions between pyromellitimide groups along a given polymer chain, and (iv) spectroscopic evidence indicates that weak interactions within the bulk of the polymer give rise to detectable inhomogeneities in optical or electrochemical properties of individual functional groups as a function of the charge on groups in their environment.

Recent Development of Advanced Functional Polymers for Semiconductor Encapsulants of Integrated Circuit Chips and High-temperature Photoresist for Electronic Applications

“…The anion radical of PMDA-ODA polyimide was observed at 720 nm by Haushalter and Smith [19] and it showed both visible and ESR spectra as evidence of a PMDA-ODA polyimide anion radical. It was confirmed in this study that the visible spectra peak is identical to an anion radical of PMDA-ODA polyimide by the absorption peak as well as identical shape of absorption peak corresponds to the ESR peak, derived from the anion radical of PMDA moiety of polymer backbone [20]. The photoreaction of ionic-bonded photosensitive polyimide by means of various spectroscopic techniques as shown in Fig.…”

The chromic and electrochemical response of CoCl2 − filled polyimide materials for sensing applications

“…The first peak involves the reduction of the neutral form to the radical anion form, while the second one, at a more negative potential, is the reduction to the dianion state. The aromatic diimide group behaves as an electron acceptor, undergoing two independent, oneelectron redox reactions comparable to a quinone [48,49]. The CV response of PI in DMAc is different from DMSO.…”

Effect of annealing on the interfacial adhesion energy between electroless-plated Ni and polyimide

“…It was reported that KOH treatment produces carboxyl as well as amide bonding on dianhydride-p-phenylenediamine (BPDA-PDA) polyimide [18][19][20]. Moreover, partially amidized polyimide is more hydrophilic, and therefore more permeable, toward the ethylenediamine (EDA) activation solution treatment [21,22]. Wet chemical pretreatment of electroless-plated Ni on polyimide films can be used to improve the interfacial bonding [12,20,23].…”