POS7-0407
Effect of Copper Oxidation States on the Interfacial Chemical Composition of Epoxy Resins
Topic
S7. Innovations in Polymeric Composites: From Design and Processing to Industrial Applications
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Shintaro Saeki (Kyushu University)
Co-Author(s)
Abstract
A better understanding of the aggregation states of epoxy resins near copper interfaces is essential for the development of high-performance sealants for electronic applications. At adhesion interfaces, thermodynamic factors distinct from those in the bulk, such as monomer segregation, as well as different reaction kinetics, including a suppressed curing rate, are expected to play dominant roles in forming the network structure. Consequently, the mechanical properties at the interface are likely to differ from those in the bulk. From a practical perspective, the oxidation states of copper surfaces can vary, which may change electrostatic interactions and thereby affect the interfacial structure and physical properties of epoxy resins. Here, to elucidate the effects of the oxidation states of copper adherends on the interfacial chemical composition and its correlation with adhesion properties, we performed X-ray photoelectron spectroscopy combined with mild sputtering using an argon gas cluster ion beam, together with peeling tests using surface and interfacial cutting analysis system, for epoxy resins composed of bisphenol A diglycidyl ether (DGEBA)/4,4′-diaminodiphenylmethane (DDM) cured on copper substrates with different oxidation states. We found that DDM segregation near the copper interfaces became more pronounced as the degree of surface oxidation of copper increased.
The enhanced DDM segregation is likely attributed to a decrease in the electron density of surface copper atoms upon oxidation, which involves electrostatic interactions with amines. The result indicates that the oxidation states of copper affect the interfacial chemical composition, thereby affecting the network structure near the interface and adhesion properties. In the presentation, the peeling strength at adhesion interfaces with copper substrates having different oxidation states will also be discussed in relation to the interfacial chemical composition.
The enhanced DDM segregation is likely attributed to a decrease in the electron density of surface copper atoms upon oxidation, which involves electrostatic interactions with amines. The result indicates that the oxidation states of copper affect the interfacial chemical composition, thereby affecting the network structure near the interface and adhesion properties. In the presentation, the peeling strength at adhesion interfaces with copper substrates having different oxidation states will also be discussed in relation to the interfacial chemical composition.
