Kyushu University, Fukuoka, Japan
Keiji Tanaka is a Distinguished Professor in the Department of Applied Chemistry, a Director at the Center for Polymer Interface and Molecular Adhesion Science, and a Vice Dean at the Graduate School of Engineering at Kyushu University, Japan. He also holds the position of Program Manager at the Japan Science and Technology Agency. Additionally, he serves as an Associate Member of the Science Council of Japan. Notably, he holds the position of Vice President at the Society of Polymer Science, Japan and serves as the Editor-in-Chief of Polymer Journal, the official journal of the Society. He is recognized as a Fellow of the American Physical Society.
He received his B.S. (1993), and Ph.D. (1997) degrees in Polymer Chemistry from the Department of Applied Chemistry, Kyushu University. Following this, he moved to the Department of Chemistry at the University of Wisconsin-Madison, where he served as a Research Associate. Returning to Japan in 2000, he joined the Department of Applied Chemistry at Kyushu University as an Assistant Professor. He progressed to the position of Associate Professor in the same department in 2005 and was subsequently promoted to a full professorship in 2009. His research centers on the structure and physical properties of polymers in confined systems, including surfaces, interfaces, and thin films. His selected awards include the Award of the Society of Polymer Science, Japan (2023), the Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology, Japan (Awards for Science and Technology, Research Category) (2022), the Award of the Adhesion Society of Japan (2018), Japan Academy Medal (2015), the Japan Society for the Promotion of Science Award (2015) and the Award of the Society of Fiber Science and Technology, Japan (2013). He has more than 280 publications, leading to an h-index of 44.
Epoxy resins, which possess a three-dimensional network obtained by a curing reaction between epoxy and amine compounds, are in a glassy state at room temperature.[1-2] They are therefore generally brittle and exhibit rather poor resistance to crack propagation, which is one of the greatest drawbacks for their practical application. To solve this problem, a better understanding of their fracture behavior, which is related to long-term durability, has been strongly desired. We herein report on how the extent of network heterogeneity affects the fracture behavior of epoxy resins. [3]Three types of epoxy resins were obtained under different curing conditions, which generated different extents of heterogeneity. The fracture behavior of the three epoxy resins was examined by in-situ scanning electron microscopy in conjunction with microbeam X-ray scattering experiments. When the epoxy resin in which a notch was pre-introduced was stretched under a small strain, the internal network structure was deformed and the extent was more significant with increasing heterogeneity. As further stretching was applied, a crack was propagated from the notch. This occurred more easily with increasing heterogeneity. That is, the toughness of the epoxy resins decreased with increasing network heterogeneity. The knowledge here obtained will be useful for understanding and controlling the toughness of epoxy resins.
©fbpol2024 – Legals notices – Webdesign : chrisgaillard.com