Researchers at two UK universities have developed a new method of chemical recycling that could prove a major breakthrough in how we use and recycle plastic.
The scientists broke down a sustainable bioplastic into its original building blocks, which could potentially allow the material to be recycled repeatedly without losing quality.
UK consumers currently recycle around 45 per cent of plastic waste – a figure that is on the increase – but, due to the limitations of current recycling methods, recycled plastic is invariably of lower quality than an original product.
This degradation in quality is the reason why plastic drink bottles cannot be repeatedly made into new bottles, but instead are used for lower-grade products such as plastic furniture, playground equipment or insulation for clothes and sleeping bags.
But now a research team at the Universities of Bath and Birmingham have developed a method of chemical recycling that could potentially make new plastics of the same quality as the original.
The new research – published in the sustainable chemistry journal ChemSusChem – moves away from traditional recycling to chemical recycling methods, which convert plastics back into their constituent chemical molecules.
“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 at the University of Bath.
“The problem is, melting plastic changes its properties, and reduces the quality, which limits the range of products in which it can be used.
“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.”
Professor Jones and his colleagues recycled plant-based polyactic acid (PLA) – a bioplastic made from starch or crop waste which is used in the production of biodegradable food packaging and disposable cutlery.
Although the use of PLA in packaging is on the increase, limitations on both its biodegradability and recyclability pose problems for the industry – something the paper’s lead author hopes their research can help to overcome.
“Whilst PLA is biodegradable under industrial conditions, it doesn’t biodegrade with home composting, and isn’t currently recycled, so at the moment it commonly ends up contributing to the tonnes of plastic waste in landfill and oceans,” said Dr Paul McKeown from the University of Bath.
“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.”
Dr McKeown and his team have extended their trial to test out a similar process for recycling PET – the material used to make drinks bottles – whilst collaborators at the University of Birmingham are also attempting scale up the research and replicate the results using larger quantities of starting chemicals.
With public awareness growing around both the issue of plastic pollution and the climate emergency, consumer demand for eco-friendly packaging is increasing all the time.
Retailers across the UK continue to expand their eco-packaging ranges, with leading manufacturer Polybags also rolling out a set of packaging standards across its catalogue to help customers choose the right sort of eco-packaging for them.
A series of handy icons assigned to each product identifies, amongst other things, whether that product is biodegradable, compostable, recyclable or made from 100% recycled material. Each icon is linked to a helpful eco-packaging guide that presents customers with all of the information they need to know about Polybags’ range of sustainable products.
Whilst these categories are often quite distinct in today’s market, this new research points to a future with a much greater crossover between bioplastics and recyclables, which is surely good news in the battle to tackle plastic waste.
