Due to the enzymes embedded in the plastic, the new plastic can be almost completely decomposed in hot water
So far, biodegradable plastics have not yet achieved the expected environmental friendliness. It doesn’t even decompose enough in industrial composting plants, let alone your homemade compost pile. However, a team led by Ting Xu, a materials scientist at the University of California, Berkeley, claims to have developed a truly compostable plastic.
This new type of plastic contains embedded enzyme particles, and once activated, they will almost completely decompose the plastic into its components. The Xup team introduced these The results are published in the journal Nature.
In the plastic production process, specially developed enzymes are embedded in the material in the form of tiny nanoparticles. The decisive development of its development is the protective shell surrounding the enzyme, which can prevent the enzyme from decomposing prematurely.
The researchers tested their method with two biodegradable plastics, polycaprolactone (PCL) and polylactide (PLA) polyester. Heated tap water is enough to destroy them, because it dissolves the protective layer of enzymes, it will almost completely degrade PCL at 40 degrees Celsius within a day, and will completely degrade PLA after six days in a 50-degree water bath.
These conditions have also been found in professional composting plants. Here, according to preliminary tests, the material disappeared after a long period of time. The lactic acid produced by the degradation of PLA can be used as a nutrient for microorganisms in compost. The finely distributed enzymes can also ensure that the plastic is completely decomposed and will not disintegrate into microplastics.
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On the other hand, if the plastic is exposed to little moisture or high temperature in daily life, it will remain stable. Xu and his team showed that even after three months in 37 degrees water, the plastic did not dissolve significantly. PLA is usually used for packaging, but it is also a widely used material for 3D printers. PCL is mainly used in the medical field, such as in medicines and bandages. In principle, nothing can prevent the same technology from being applied to other plastics.
The team is currently working to modify the shield. One of the goals is to stop the degradation of the plastic at a certain point so that it will not be completely destroyed, but can be recast and recycled.
photo: Ivan Radic