New Plastics Produced - Blog With Sidra

  Plastic Produced A dash of polymer-degrading enzymes can make biodegradable plastic wraps and forks truly compostable. Ting Xu and collea...

 

Plastic Produced

A dash of polymer-degrading enzymes can make biodegradable plastic wraps and forks truly compostable.

Ting Xu and colleagues published a paper in Nature showing that with moderate heat, enzyme-laced plastic films can be degraded in standard fertilizer or plain tap water in just days or weeks . Xu, a polymer scientist at the University of California at Berkeley and Lawrence Berkeley National Laboratory, says:

Xu says he often finds pieces of biodegradable plastic in the compost his parents collect for their garden. Most biodegradable plastics end up in landfills, where conditions are not conducive for them to degrade. For this reason, they do not decompose faster than normal plastics.

Introducing polymer-degrading enzymes into biodegradable plastic should accelerate decomposition. However, this process often results in the formation of potentially harmful microplastics , which occur in ecosystems around the world as a side effect. The enzymes clump together and randomly break the molecular chains of the plastic, leading to imperfect degradation. Xu says:

This is even worse than if we didn't separate them in the first place.

His team added separate enzymes to two biodegradable plastics, including polylactic acid, which is commonly used in food packaging. They placed the enzymes together with another previously developed component, a degradable additive that ensures the enzymes do not clump together and break down. The enzymes alone captured the ends of the plastic's molecular chains, breaking the chain links and preventing microplastic formation.

The addition of enzymes often makes plastics expensive and compromises the basic properties of the plastic. However, Xu's enzymes make up only 0.02% of the weight of plastic, and the plastics produced with it are as strong and flexible as the plastics typically used in shopping bags. Another problem that Xu's team is trying to overcome is that this technology does not work on all plastics because their molecular structures vary. Xu has filed a patent for the technology, and one of the paper's co-authors has also founded a startup to commercialize the product. Xu concludes his words as follows:

We want this technology to be in every market.