New research overcomes incompatibility in recycling plastics

United States: Cornell University in the USA has developed a new additive that 'melds incompatible types of plastic together'. Hailed as a 'remarkable' innovation that is expected to boost plastics recycling efficiency, it has won the 2017 Newcomb Cleveland Prize and US$ 25 000 awarded by the American Association for the Advancement of Science. This celebrates the design of a 'multiblock polymer' that combines polyethylene and polypropylene materials into a single plastic composite.

The research has been led by Professor James Eagan, who published results in the Science journal last year. He estimates that polyethylene (PE) and polypropylene (PP) make up two-thirds of the world’s plastics, but recycling them together has proved to be challenging owing to their distinct chemical structures.

The new multiblock polymer changes this by basically ‘anchoring’ the two different plastics together, the researchers explain. To test the additive, the team at Cornell welded together a laminated sheet of PE and a sheet of PP by adding the new additive in between.

Compatible with both PE and PP, this enables plastic sheets to be linked up and stuck together. The new material is rigid and mechanically tough, reports Professor Geoffrey Coates from Cornell’s department of chemistry and chemical biology.

He hopes this will lead to innovations in the way plastic products are designed. ‘Say we can make a milk jug where we use 5% less polymer because the properties are better - think of the world’s savings on all that plastic,’ he muses.


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