Can Plastics Save the World?

It seems that plastics – the oft-attacked ‘destroyer of the environment’ – might turn out to be the saviour of the planet, if Japanese scientists get their way.

Researchers at the National Institute of Advanced Industrial Science and Technology (AIST) have developed a blended plastic that uses carbon dioxide as a monomer precursor – some of which is derived from ‘fixed’ CO2.

Fixing works by removing the gas from the atmosphere and rendering it inactive as a greenhouse gas. A plethora of projects exists to do this, and all of them are trying to do two things: extract CO2 from the air; then do something with it.

One eminent UK scientist has suggested dumping dry ice ‘torpedoes’ into deep ocean wells, where it would form carbon dioxide hydrates.

The Japanese project appears a practical and useful way of using ‘excess’ CO2. Its step forward is to find a way of blending the base polymer – dubbed PPC, or poly (propylene carbonate) – to make it usable.

“It was [previously] an unsuitable polymer for practical use,” say the researchers.

By blending PPC – which is sticky and rubbery, with a low glass transition temperature – with aliphatic polyesters, the researchers have created a high performance material with an elastic modulus of 2.4GPa and strength of 17.9MPa. Its performance outstrips that of several commodity resins, such as PP, PE and PVC.

PPC comprises 43% of ‘fixed CO2’ by weight, while the final blend contains about 30%.

The initial target for the material is in general structural applications, but it could later be applied to film and packaging materials due to its transparency and gas barrier performance.

AIST: www.aist.go.jp

Specific research page: www.aist.go.jp/aist_e/latest_research/2008/20081226/20081226.html