Plastic waste from millions of cars scrapped every year could be upcycled to make the world’s strongest known material for reuse on the production line, scientists have found.
Researchers in Texas retrieved plastic found in cars destined for landfill and turned it into graphene – the ultra-thin, stretchy material used to strengthen car parts, said a paper in Communications Engineering.
The process of upcycling the waste — recycling a product into material more valuable than the original — was found to be more environmentally friendly than traditional techniques, using less water and energy.
The practice could also save money with new graphene costing up to $200,000 a tonne, the researchers said.
With 1.4 billion cars on the road worldwide, “responsible disposal of vehicles at the end of life is a pressing environmental concern”, said the paper. The authors said commercialisation of the process was about four years away.
Two researchers from the University of Manchester in the UK won the Nobel Prize for Physics in 2010 for extracting graphene from a piece of graphite.
The flexible, carbon-based material, with the thickness of only one atom, conducts electricity and heat and is 200 times as strong as steel. Few industrial purposes have been found for the substance but it is used by motor manufacturers to strengthen car parts and reduce noise.
The researchers found the 1 trillion kilograms of car plastic waste destined for the scrapheap each year could be converted to graphene using a flash of electricity in a process known as flash joule heating.
The researchers found they could mix together different shredded plastics, using bumpers, mats, seating and door parts from a Ford pickup to create their graphene. They said that it had the same qualities as graphene made from scratch.
"This provides an avenue for the upcycling of huge amounts of waste plastic, much of which is engineering plastic and cannot be recycled anyway," said one of the authors, James Tour, of Rice University in Houston, Texas. "It can have profound implications in the automotive industry."