'Designer' polymers

It's almost axiomatic that complex polymers require complex reaction conditions.

Highly-purified solvents and extremely low temperatures are often needed for 'designer' polymers, which increases the cost of production and therefore of the material itself. But researchers at the University of Warwick have now developed a process which 'grows' the polymers in common solvents and at manageable temperatures.

David Haddleton and colleagues call the process living/controlled polymerisation. It depends on the use of a particular catalyst containing copper I bromide and a diimine ligand whose properties give the chemists very precise control over the reaction dynamics.

Using this system, they can design functionality and shape into the polymers, making star-shaped, comb-shaped and block systems easily. Moreover, the mechanisms are inert to other types of chemical functionality, so the system can use solvents which are normally too reactive for polymerisation - water and alcohol. The catalyst works at temperatures from 25 degrees to 150 degrees C.

Effect polymers can be used to make inks water-fast, to make non-sticky hairsprays, and for many other applications in high-value areas. Haddleton has founded a spin-off company, Warwick Effect Polymers, to commercialise the technology.