Hydrogen-bonded TPE key to automotive adhesive advance

Nagoya, Japan – Researchers at Nagoya University have advanced structural adhesives for the automotive industry based on thermoplastic elastomers (TPEs).

Adhesives are traditionally made using epoxy resins, which means they lack flexibility and are susceptible to damage under impact, said the university in a 25 Sept report.

To overcome this, the researchers combined a hydrogen-bonded styrenic TPE, previously developed by Nagoya University, with an adhesive.

The combination resulted in a new type that offers both flexibility and “outstanding impact resistance,” according to the research team.

The adhesive, it claims, offers “unprecedented impact strength of up to 22 times higher than traditional epoxy-based adhesives that do not incorporate any rubbery additives."

The stronger and more flexible adhesive is, therefore, expected to enable the production of lighter automotive components, using aluminium and fibre-reinforced plastics.

The hydrogen-bonded TPE allows the adhesive to stretch and return to its original shape, improving its stress dissipation during impact, explained the report.

Hydrogen bonds formed within the elastomer in the adhesive, it added, allow the molecular structures to separate and reconnect instantly under stress, further increasing its toughness

“Structural adhesives are expected to play a key role in reducing vehicle weight, which is critical for improving fuel efficiency and lowering emissions,” said research co-author Atsushi Noro.

The new adhesive’s ability to bond various materials, such as metals and fibre-reinforced plastics, will enable the design of lighter vehicles without compromising safety or performance, Noro added.

By enabling lighter vehicles, the product is expected to also contribute to the sustainability of the automotive industry, the researchers pointed out.

The team also aims to find applications for the adhesive in industries such as aerospace and construction: reducing the weight of materials used and reducing carbon footprint.