Metal-free technique supports wider use of controlled radical polymerisation

A technique called Atom Transfer Radical Polymerisation is emerging as a key process for creating well-defined polymers for materials including adhesives and electronics but current ATRP methods use metal catalysts, which are a hindrance to applications in which metal contamination is problematic.

This new method of radical polymerisation – developed by chemists and materials scientists from University of California, Santa Barbara and The Dow Chemical Company - doesn’t involve heavy metal catalysts like copper. Instead, the metal-free ATRP process uses an organic-based photocatalyst and light as the stimulus for the highly controlled chemical reaction.

In a statement, Craig Hawker, director of the Dow Materials Institute at UC Santa Barbara said: ‘The grand challenge in ATRP has been: how can we do this without any metals?

‘We looked toward developing an organic catalyst that is highly reducing in the excited state, and we found it in an easily prepared catalyst, phenothiazine.’

‘It’s ‘drop-in’ technology for industry,’ said Javier Read de Alaniz, principal investigator and professor of chemistry and biochemistry at UC Santa Barbara. ‘People are already used to the same starting materials for ATRP, but now we have the ability to do it without copper.’