Step towards 'proper' plastic recycling as researchers recover 92% of plastic

A team of researchers at ETH Zurich have broken down plastic into its molecular building blocks, recovering 90% of them - and it could lead to a new way of using plastic.

Most of the plastic we use is not recycled - and one of the reasons is that recycling doesn’t produce great products.

But if a process can break down the long chain polymers in plastic into building blocks - ‘monomers’ - it could lead to a circular economy where plastic is recycled with no loss in quality.

Polymers are the basis of many everyday plastics, such as PET and polyurethane.

Athina Anastasaki, Professor of Polymeric Materials at ETH Zurich, is attempting to produce polymers that can be easily broken down into their building blocks so that they can be fully recycled.

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Her team broke down polymethacrylates (e.g. PlexiGlass) that were produced using a specific technique called reversible addition-fragmentation chain-transfer polymerisation — otherwise known as RAFT.

The new method has already attracted the attention of industry, Professor Anastasaki says.

Anastasaki says, "Our method could conceivably be developed even further to involve the use of a catalyst. This could increase the amount recovered even more.”

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The catch is that, "Products made with RAFT polymerisation are more expensive than conventional polymers," says Anastasaki.

But the team are already working on methods to make it cheaper - and researching whether other polymers can be depolymerised.

Anastasaki says, "It will take a lot of time and research before the process is established in the chemical industry."

"We are only at the beginning of our research into depolymerisation. There are over 30,000 studies on developing new polymerisation strategies, with only a handful of them addressing the subject of monomer recovery.”

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Plastic pollution now affects almost all species in the world’s oceans, and is set to quadruple by 2050, a report by wildlife group WWF found this year.

The report found that 88% of marine species, from plankton to whales are affected by contamination.

Pollution hotspots such as the Mediterranean, the East China and Yellow Seas, and the Arctic sea ice are already exceeding dangerous thresholds of microplastics.

The report commissioned by the WWF reviewed 2,590 studies and found that by the end of the century marine areas more than two and a half times the size of Greenland could exceed ecologically dangerous thresholds of microplastic concentration.

The amount of marine microplastic could increase 50-fold by then, the wildlife charity warned

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