Many plastics labelled as biodegradable are usually just compostable under industrial facilities, but scientists at the University of Bath, UK, (UB) have discovered a way to break down PLA plastic using only UV light.
Because of increased public concern over plastic waste. PLA (Polylactic acid) plastics – made from fermented lactic acid from sugars – are now widely used as a more sustainable alternative to crude oil-derived plastics. It is often marked as biodegradable, however, it can only biodegrade under industrial conditions of high humidity and temperature, and cannot be achieved in natural environments.
The research team at the Centre for Sustainable and Circular Technologies (CSCT) at UB, has found a way to adjust the degradability of the PLA plastic by incorporating a different amount of sugar molecules into the polymer.
They found that incorporating as little as 3 per cent sugar polymer units into PLA led to 40 per cent degradation within six hours of exposure to UV light.
According to the scientists, this technology is compatible with existing PLA plastic manufacturing processes, and could potentially be scaled immediately by the plastic industry.
“Our research adds sugars into the polymer chains, linking everything together by bonds that can be broken using UV light,” explains Dr Antoine Buchard, lead searcher of the study.
“This could make the plastic much more biodegradable in the natural environment, for example in the ocean or in a garden compost heap.”
Buchard added the study has yet to be applied in real-life plastic objects tested in sunlight, but they hope their discovery could be used in the future to make plastics that are just as strong but can break down easily at their end-of-life.