New polymer possibilities

Researchers at Moscow State University have modified the common synthetic polymer, polyurea, to gain precise control over the elasticity of a new family of polymers. These could be used in a wide range of applications requiring thin coatings with varying mechanical, protective, insulating, and decorative properties.

Polymers such as polyurea are widely used as coatings in many manufacturing fields, including building construction, shipbuilding, the petrochemical industry, aircraft and automobile manufacture. Researchers worldwide are looking for ways to extend their range and properties.

However, making new polymers with useful new characteristics can be a complicated and expensive technological process, says Maxim Arzhakov, a chemist on the research team.

Arzhakov and his colleagues realized that the most effective way to generate new polymers with properties that could be readily controlled might be to modify inexpensive existing polymers that are readily available in large quantities. They describe their success in modifying polyurea to control the properties of insulation coatings in the journal Doklady Physical Chemistry¹.

They began their investigation with two industrial polyureas that had widely differing elasticities. The research team explored the chemical challenge of finding additives that would achieve a range of intermediate properties between the soft rubbery texture of one of the starting polymers and the rigid plastic nature of the other.

They found that causing the polyurease structure to fracture and then heal by adding varying amounts of fluorine-containing hardener and a chemical plasticizer, at a combined contribution of no more than 2% by weight, allowed them to control the elasticity across a wide range. In technical terms, the ‘elastic modulus’ – a measure of the force needed to deform a material – could be varied from 22 to 172 Megapascals, a very significant range.

“We were surprised that such minor chemical modifications allowed us to produce the desired continuous set of polyurea grades between rubbery and hard,” Arzhakov says. He adds that a key distinctive feature of their work is that the modified polyurea samples were prepared using high-pressure spraying technology developed by the Russian company, INTERSKOL – Polymer technologies, where two members of the research team are employed.

“This spraying technology can be used to produce seamless and perfect monolithic coating of the desired thickness on materials with any shape and configuration,” Arzhakov says.

The team now hope to widen the research effort into other polymers, while taking advantage of the link with INTERSKOL to move towards commercial applications.