This acid may be key to better electronics, adhesive strength

An acid used in medicine and to flavour some drinks may help develop electronic components and certain adhesives which are more durable and better for the environment, scientists say.

The researchers at Purdue University in the US have discovered a method for using tannic acid to help create improved adhesives, coatings and manufacturing composites.

They are using the discovery for epoxy-based polymers -- which are considered among the most versatile and useful adhesive agents because of their excellent mechanical strength and strong sticking power.

"There are few high-temperature hardeners that are sustainable," said Jeffrey Youngblood, a professor at Purdue's College of Engineering.

"Our technology is designed to improve sustainability without sacrificing performance," Youngblood said.

Epoxy polymers are used in a wide range of applications including coatings, adhesives, structural composites, insulating materials and components of electronics.

A hardening agent is added to the polymer to ensure stability and stiffness in high-temperature environments.

"We are using tannic acid as the hardener. It is more sustainable than other options, has less environmental impact and is relatively inexpensive," Youngblood said.

Tannic acid is a well-known, naturally occurring polyphenolic compound used in antioxidants.

Youngblood said the team's tannic acid solution also has shown in testing to be stable and maintain needed stiffness when exposed to high temperatures.

"Sustainable materials typically have lower performance, which compromises the public perception and penetration into the market. Here, such a trade-off is not necessary," Youngblood said.