Biodegradable plastic cling film that disintegrates within a year and can also be recycled has been developed by British scientists in a world first.
Polymateria, based at Imperial College in White City, west London, has created a polyethylene plastic that breaks down in 226 days and can be recycled in UK facilities.
Last autumn it set the UK standard for biodegradable plastic with its invention, which breaks down to a harmless sludge or wax, even when left out in the open air.
Most biodegradable or compostable plastic, including bioplastics made from sugars from corn starch or ethanol, is not suitable for conventional recycling because it does not break down in the same way as plastic does.
But Polymateria’s biodegradable polyethylene plastic has now passed independent tests clearing it to be recycled into products like flower pots or pallets.
“This should give us all hope. This should define a new era, in not thinking this is either/or. “These shouldn’t be mutually exclusive solutions, they have to be complementary solutions. And this is the first time that we’ve seen anyone provide ISO-accredited data and evidence that it’s possible.”Polymateria chief executive Niall Dunne
The environmental benefits of bioplastics compared to traditional plastics are a matter of debate.
While they are not made from oil, reducing the greenhouse gas emissions created by the oil industry, they do not break down safely outside of industrial composting facilities, meaning they can cause the same danger to marine life that is posed by ordinary plastic.
Biodegradable plastic is controversial among industry and green groups, with critics arguing that telling consumers plastic will break down encourages them to dispose of it irresponsibly.
Earlier iterations of plastic claimed to be biodegradable by their manufacturers also did not live up to the hype, causing scepticism.
Mr Dunne argues that most plastic in nature comes from leakage from waste systems, rather than littering.
“If we just stay putting huge pressure on the recycling system and expecting them to do everything, it’s not going to happen. “I think equally, if we just think biodegradability is the answer, it’s also not going to happen.
The key is both of those things working together, and then we’ve got a chance,” he said.
Polymateria’s plastic is based on the same structure as traditional polyethylene, but has been biologically and chemically altered to mean it disintegrates in nature and does not leave behind microplastics, the company says.
Its process involves adding a substance to the plastic as it is manufactured, which will later start a chemical reaction that causes the crystalline structure of the plastic to break down when exposed to the elements, something that does not happen in ordinary plastics.
It also biologically modifies the plastic to make it “attractive to nature”, allowing microbes and fungi to digest it.
The start of this process can be delayed by different amounts of time depending on the product, with plastic labelled with a “recycle by” date after which it can start to break down.
Dr Michail Kalloudis, director of polymer science at Impact Solutions, the lab which independently tested the plastic, said it was the first biodegradable plastic which could be safely recycled.
“Biodegradable packaging materials are not meant to be mixed with polyethylene materials. Polymateria’s is an exception because it’s based on polyethylene,” he said.
The plastic is already on British supermarket shelves in food packaging, but the company will not yet say in which specific products.
As well as for cling film, the flexible, thin plastic can be used in salad bags, post bags for fashion items and in plastic used to bind together multipacks for shipping.
Last week House of Cards actress Robin Wright announced that her fashion brand Pour les Femmes would be using the plastic in its clothing deliveries to customers and shops.
The company has also developed a rigid polypropylene material used for making products such as drink cups, which is still in the final phases of testing for recyclability but has already been found to break down in the natural environment in 336 days.
“As a science-focused business developing technology to address global environmental challenges, we’re proud to see them flourish and to continue our role in supporting Polymateria’s efforts to build a circular economy.”Dr Simon Hepworth, director of enterprise at Imperial College London