New biodegradable plastic that completely decomposes in a week with heat and water is launched in the United States

Biodegradable plastics have long been thought to help solve the problem of plastic pollution, but today most "compostable" plastic bags are mainly made of polylactic acid (PLA), which does not break down during the composting process and can contaminate other Recycle plastic

Previously, Ting Xu, a professor of materials science and engineering at UC Berkeley, and her research group discovered an enzyme that degrades toxic organophosphorus chemicals and designed molecules called random heteropolymers, or RHPs, which Molecules encase the enzyme, gently holding it together without limiting the enzyme's natural resilience, protecting the enzyme from disintegration

In this study, the research team used a similar technique to make plastic by encapsulating billions of nanoscale edible polyester enzymes in RHP and embedding them in plastic resin beads

The study found that the RHP-encapsulated enzymes did not change the properties of the plastic

For PLA, the researchers used an enzyme called proteinase K, which chews PLA into lactic acid molecules, and for polycaprolactone (PCL), lipase

To trigger plastic degradation, just add water and a little heat

98% of plastics made using this process degrade into small molecules, and the process avoids the creation of microplastics

The researchers say that the modified polyester does not degrade at lower temperatures or when it is briefly wet, but only when soaked in warm water, which means the plastic can be composted at home

(Zhang Jiaxin)

"China Food News" (May 05, 2021 Edition 04)

(Editor in charge: Gao Na)