Researchers turn biodegradable plastic into foam

‘Tweaking temperature and pressure, there is a window where we can make good foams,’ study’s author says

(PA)

Researchers have shown how biodegradable plastic can be turned into a foam that can be used as insulation in walls or in flotation devices.

A team at the University of Canterbury in New Zealand put biodegradable knives, forks and spoons into a chamber filled with carbon dioxide.

As they increased the pressure inside the chamber, the gas dissolved into the cutlery.

When the pressure was subsequently released, the carbon dioxide expanded inside the plastic, creating "foaming".

"Tweaking temperature and pressure, there is a window where we can make good foams," said Heon E. Park, author of the study Physics of Fluids, published by AIP Publishing on Tuesday.

"It's not that every temperature or every pressure works. We found what temperature or what pressure is the best to make those nonfoamable plastics into foams."

The researchers found that lower pressure in the chamber resulted in bulkier foams.

It can take months or even years for biodegradable plastics to disintegrate, and even then scientists say microplastics may persist in the environment, seeping into the ground, rivers or the sea.

The researchers say their findings could help to reduce the amount of biodegradable plastics ending up at landfill sites.