Photo: Georgia Institute of Technology
Biodegradable plastic wrap made from crab shells and wood pulp Photo: Georgia Institute of Technology

Crab shells and trees combine to create new food packaging

July 26th, 2018

American scientists have successfully developed material akin to plastic wraps using crab shells and wood pulp.

Researchers at Georgia Institute of Technology (GIT) have found a way to use discarded crab shells and tree fibres to create a sustainable material similar to everyday plastic wraps.

Crab shells reportedly contain a substance called chitin, the second most common polymer in existence. In the study, published in ACS Sustainable Chemistry and Engineering, GIT scientists found that tree fibres are also rich in cellulose, the most common polymer.

The material developed by the team is created by spray-coating a polylactic acid (PLA) base with these two materials in alternating layers.

“The chitin and the cellulose are oppositely charged,” said Carson Meredith, lead author of the paper. “That allowed them to build nice sub-layers as they’re coated and create dense, thin films that block the transmission of oxygen.”

Researchers found that even though the material is very similar to petroleum-based plastic, it helps to keep food fresher for a longer period of time as less energy penetrates biodegradable plastics.

Scientists had previously tried to transform sugars in cornstarch, cassava and sugarcane into biodegradable plastic to tackle the issue of plastic waste.

However, researchers at Columbia University conducted a study on this form of bioplastic and concluded that they could be a greater source of pollution than traditional petroleum-based ones.

Humans have already produced 8.3 billion metric tonnes of plastic, a bulk of waste equivalent in weight to 25,000 Empire State Buildings or 80 million blue whales.

In a 2017 study published in the Journal Science Advances, researchers estimated that the amount of plastic in our landfills would exceed to 12 billion metric tonnes by 2050.

Plastic is the most durable form of trash found discarded in the natural environment, and scientists are trying to innovate methods, such as lab-made plastic eating bacteria, to get rid of it.

About the Author

Shamim Malekmian

Shamim Malekmian is a Cork-based freelance journalist and contributor to the Irish Examiner, Cork’s Evening Echo and The Green News.

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