A new thermoplastic rubber material has emerged from Nagoya University alongside the Zeon Corporation. Based on an ionically functionalized block polymer, “i-SIS” packs a high impact resistance, even when compared to plastics reinforced with glass-fibers.

Thermoplastic elastomers (known as TPEs) are plastic and rubber that have thermoplastic and elastomeric properties, respectively. Useful during injection molding, the thermoplastic property lets objects stretch but return closely to their original shape. The most well-known TPEs are styrenic block polymers containing molecular blocks of polystyrene. Created by Shell Chemical Company in the 1960s, they have continued to be further developed and refined. The global market for TPEs is worth billions of dollars annually and will continue to be in high demand.

New lightweight options for the automotive industry

Improving upon the mechanical properties of styrenic block polymers, the researchers at Nagoya University and the Zeon Corporation are the first to evaluate the impact resistance by this new material alongside glass-fiber reinforced plastics. The tensile tests showed very promising results. This material would be considered valuable in the automotive industry, especially as lightweight materials that can also withstand damage are highly sought. This i-SIS could be the next generation of elastomeric material used in both inside and exteriors of transportation vehicles.

Impact abstract. Source: ACS Omega 2021

Further studies are needed to see if this outperforms the TPEs already on the market. While they are safe and considered non-toxic, they are costly, tend to lose their shape or “creep” after too much stress and are not made to reach high temperatures without losing some of their rubbery properties.