Scientists
have figured out a way to recycle plastic hundreds of times without
losing the quality of the material. Currently, most plastics can only be
recycled two or three times before the quality degrades so much that it
becomes unusable.
Researchers at the University of Bath figured
out the method to recycle plant-based plastics (PLA), which are not yet
recycled at all in the UK.
“Most plastic is currently recycled
using mechanical methods, where they are chipped into granules and
melted down before being moulded into something new,” said Professor
Matthew Jones, from the Centre for Sustainable & Circular Technologies.
“The
problem is, melting plastic changes its properties, and reduces the
quality, which limits the range of products in which it can be used.”
The plastic degrades so that old bottles cannot be turned into new ones.Unsplash
This
means that plastic drinks bottles will not be recycled into new drinks
bottles but used to make lower grade products such as water pipes, park
benches and traffic cones.
“Our method of chemical recycling
overcomes this problem by breaking down plastic polymers into their
chemical building blocks, so they can be used all over again to make
virgin plastic without losing any properties,” Jones added.
The
researchers recycled plant-based PLA, which is made from starch or crop
waste instead of petrochemicals and is used in “biodegradable” food
packaging and disposable cutlery and cups. The team has also started
trialling a similar process for recycling PET, which is used for drinks
bottles.
Scientists are working on a more effective way to break down plastic.Unsplash
At
the moment, around 45% of plastic waste is recycled annually in the UK
and is on the increase. The scientists are working to make their method
of breaking down plastics for more effective recycling techniques
available on a large scale to curb the plastic crisis.
“PLA is
being increasingly used as a sustainable alternative for single-use
plastics,” said Dr Paul McKeown from the University of Bath. “Whilst
it’s biodegradable under industrial conditions, it doesn’t biodegrade
with home composting, and isn’t currently recycled, so it commonly ends
up contributing to the tonnes of plastic waste in landfill and oceans.
“There
is no single solution to the problem of plastic waste – the approach
has to be a combination of reducing, reusing and recycling. Our method
of chemical recycling could allow carbon to be recycled indefinitely -
creating a circular economy rather than digging more up from the ground
in the form of fossil fuels or releasing it into the atmosphere as a
greenhouse gas.”
