Coconut oil used to recycle car parts for insulating foam
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Czech researchers have used coconut oil and microwaves to help solve the longstanding problem of how to recycle leftover plastics from cars and reuse them for insulating foams.
Millions of tonnes of unwanted end-of-life cars are thrown away every year, producing an enormous amount of waste rubber, plastic and metal.
Useful items such as fridges, cushions, packaging and insulation can be manufactured from recycled types of plastic found in scrap cars: polycarbonate (PC) and polyurethane (PUR). While researchers have long known that these useful plastics exist in old cars, it has proved a tantalising challenge to extract them.
Largely, this is because PC and PUR materials taken from scrap cars require an arduous chemical recycling method, which is sensitive to interference from paints and other coatings. These complications can cause the recycled product to deteriorate.
Simply adding certain types of recycled PC and PUR materials to existing insulating foams may sound like a good compromise, but these foams often end up unusable: too dense or too brittle.
While 30 years of research has mostly failed to extract useful plastics from scrap cars, researchers from Cracow University of Technology and the Institute of Macromolecular Chemistry of the Academy of Sciences of the Czech Republic decided to try using an unusual ingredient: coconut oil.
They had previously done research into breaking down PC and found that coconut oil played a role in this degradation - a strong hint that this innocuous oil, often used in cosmetics, could be key in helping to recycle plastics.
In ACS Sustainable Chemistry & Engineering, the researchers detail a new method for recovering renewable PC and PUR from waste car plastics using coconut oil and microwaves to convert them into recycled polyols. A trial demonstrated that the resulting products did not degrade, were stable at high temperatures and could be incorporated into insulation foam without the problems that have troubled other researchers.