Researchers at Nagoya University and Zeon Corporation received two awards in May 2023 for the development of tough noncovalently-functionalized styrenic thermoplastic elastomers. They chemically modified Zeon's QuintacTM, a styrenic thermoplastic elastomer marketed by Zeon Corporation, to develop "tough functionalized styrenic thermoplastic elastomers". Since the newly developed SIS with noncovalently-functionalized polyisoprene is a lightweight yet tough and highly impact resistant material, its development should contribute to the goal of reaching a net-zero carbon and sustainable society.
The researchers received the 2022 SRJ Technology Award from the Society of Rheology, Japan (SRJ), a member of the International Committee on Rheology (ICR) and the 35th SRIJ Award from the Society of Rubber Science and Technology, Japan (SRIJ), a member of the International Rubber Conference Organization (IRCO). The SRJ Technology Award is given to people who have made outstanding achievements in rheology-associated technology (including engineering and industrialization technology). Meanwhile, the SRIJ Award is given to those who have contributed to the development of science and technology in rubber and rubber-related fields, or to the development of the industry field, where their achievements are extremely remarkable.
A thermoplastic elastomer (TPE) is a polymer material synthesized by chemically connecting a plastic component and a rubbery component at room temperature. It can be used as natural or synthetic rubber at room temperature, while also being thermally processable as plastics. Due to its usefulness as a material that exhibits softness, stretchability and thermoprocessablity simultaneously, it is used in applications such as resin modifiers, asphalt modifiers, adhesives, interior and exterior parts of automobiles, and wire-covering materials. Among TPEs, the market share of styrenic thermoplastic elastomers is estimated to account for about 35% of the world's TPE market (more than five billion dollars per year). A typical example of styrenic thermoplastic elastomers is QuintacTM, a polystyrene-b-polyisoprene-b-polystyrene (SIS) block copolymer marketed by Zeon Corporation. Recently, there has been demand for the development of a new TPE that is light in weight but has a higher strength and toughness in comparison to existing TPEs already on the market.
Responding to this demand, a Nagoya University research group led by Atsushi Noro at the Graduate School of Engineering and the Institutes of Innovation for Future Society, in collaboration with Zeon Corporation, synthesized tough noncovalently-functionalized styrenic thermoplastic elastomers by introducing more than a few mol% of non-covalent functional groups such as hydrogen-bonding functional groups and ionic functional groups to the polyisoprene part (polydiene part) of Zeon's QuintacTM SIS. In particular, the tensile strength, toughness, and impact resistance of ionically-functionalized SIS (i-SIS) are three times higher than those of Zeon's QuintacTM SIS without functional groups. The awards were given to them due to the high novelty and scientific significance of the research achievements supported by publications of two peer-reviewed papers (URL: https://doi.org/10.1021/acsomega.1c05609 and https://doi.org/10.1016/j.polymer.2021.123419) and the multiple patents granted both in Japan and overseas for the development.
Nagoya University has also received grants for related research from the New Energy and Industrial Technology Development Organization (NEDO) to continue the research and development of these vital and attractive materials.
The papers, "Highly Impact-Resistant Block Polymer-Based Thermoplastic Elastomers with an Ionically Functionalized Rubber Phase" and "Extremely tough block polymer-based thermoplastic elastomers with strongly associated but dynamically responsive noncovalent cross-links," were published in ACS Omega on Dec 20, 2021, at https://pubs.acs.org/doi/10.1021/acsomega.1c05609 (open access), and Polymer on Jan 19, 2021, at https://doi.org/10.1016/j.polymer.2021.123419, respectively.
Junior Associate Professor, Graduate School of Engineering and Institutes of Innovation for Future Society, Nagoya University