Ultraviolet light can make plastic biodegradable, finds UK study

The researchers at the University of Bath discovered that adding sugar units to polymers increases their degradability when exposed to UV radiation.
 

Published: 05th July 2022 04:27 PM  |   Last Updated: 05th July 2022 08:23 PM   |  A+A-

For representational purposes. (File Photo | AP)

By PTI

LONDON: Researchers in the UK have developed a novel method to break down plastics using just ultraviolet (UV) light. The researchers at the University of Bath discovered that adding sugar units to polymers increases their degradability when exposed to UV radiation.

UV radiation has a wavelength of 10 nanometres (nm) to 400 nm, shorter than that of visible light, but longer than X-rays. Many plastics that bear the biodegradable label can only be composted in industrial settings.

The researchers noted that public concern about plastic waste has led to the widespread usage of PLA (Polylactic acid), which is a renewable, sustainable alternative to polymers made from crude oil.

PLA is used in everything from throwaway cups and teabags to three-dimensional (3D) printing and packaging. Although PLA is sometimes advertised as biodegradable, it only dissolves under industrial composting conditions of high temperatures and humidity, which are not possible in residential compost heaps.

It is also not easily degradable in natural environments, such as soil or the ocean.

"Lots of plastics are labelled as biodegradable, but unfortunately this is only true if you dispose of it in an industrial waste composter - if put into domestic compost heaps, it can last for years," said Antoine Buchard from the University of Bath.

The research, recently published in the journal Chemical Communications, demonstrated a method that could increase the rate at which these polymers degrade in the environment. The researchers found that by adding various quantities of sugar molecules to the polymer, they could modify how quickly the plastic degrades.

They discovered that incorporating as little as 3 per cent of sugar polymer units into PLA caused it to degrade by 40 per cent in only six hours when exposed to UV light.

"Most PLA plastics are made up of long polymer chains which can be difficult for water and enzymes to break down. Our research adds sugars into the polymer chains, linking everything together by bonds that can be broken using UV light," said Buchard, who led the research.

The method weakens the plastic, breaking it down into smaller polymer chains that are then more sensitive to hydrolysis. This could make the plastic much more biodegradable in the natural environment, for example in the ocean or in a garden compost heap.

The technology is compatible with existing plastic manufacturing processes, meaning it could potentially be tested and adopted quickly by the plastics industry, the researchers said.

They hope their findings will be used in the future by the plastics industry to help make plastic waste more degradable at the end of the life of the product.



Comments

Disclaimer : We respect your thoughts and views! But we need to be judicious while moderating your comments. All the comments will be moderated by the newindianexpress.com editorial. Abstain from posting comments that are obscene, defamatory or inflammatory, and do not indulge in personal attacks. Try to avoid outside hyperlinks inside the comment. Help us delete comments that do not follow these guidelines.

The views expressed in comments published on newindianexpress.com are those of the comment writers alone. They do not represent the views or opinions of newindianexpress.com or its staff, nor do they represent the views or opinions of The New Indian Express Group, or any entity of, or affiliated with, The New Indian Express Group. newindianexpress.com reserves the right to take any or all comments down at any time.

flipboard facebook twitter whatsapp