Roosevelt Institute | Cornell University

What Your Chess Pieces and Shrimp May Soon Have in Common

By Julia MalitsPublished November 6, 2014

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Researchers at the Wyss Institute of Harvard University have synthesized bioplastic products composed of fully biodegradable chitosan. Their discovery has the potential to revolutionize the polyethylene-based plastics production industry if their work is applied on a larger scale.
By Julia Malits, 11/6/14

From cell phones to food containers, the use of plastics has become an inescapable part of everyday life. Its use is so extensive that 300 million tons of plastic are produced every year, but only 3% of which is recycled. This unsustainable and continuous overproduction of plastics poses serious concerns. For one, discarding plastic is highly problematic because they typically wind up in landfills and oceans where they take centuries to degrade. As the plastics slowly break down, they release toxins, such as BPA and phthalates into the environment. Meanwhile, fish, which are direct players in the human food chain, ingest 24,000 tons of plastic materials every year, according to a recent report by CBS.

Producing plastics also requires burning copious amounts of petroleum, which increases air and water pollution. Even recycling does not offset the effects of toxic processes that consume significant amounts of energy, according to Creeklife. Based on these factors, there is a high demand for developing an alternative to traditional, polyethylene-based plastics.

So far, the most popular alternatives have been plant-based bioplastics, which are compounds derived from renewable biomass sources. They have started to replace polyethylene in relatively weak, simple objects such as disposable cutlery and grocery bags. However, they are insufficient because they cannot be molded into more sturdy and complex structures commonly made from polyethylene, preventing them from being used in mass manufacturing.

 Fortunately, a promising alternative has recently been cultivated at the Wyss Institute of Harvard University. Through bioengineering, researchers at the Wyss Institute have synthesized an unprecedented chitosan-based bioplastic. A form of chitin, chitosan has a characteristically tough structure and is the main substance in the shells of crustaceans, the cuticles of insects, and the wings of butterflies. Chitosan's sturdiness has allowed researchers to successfully mold it into complex three-dimensional structures. And as the second most abundant organic material on the planet, chitosan is easily available for plastics production. Copepods (small marine crustaceans) alone produce one billion tons of chitin annually. Capitalizing on the durability, abundance, and renewability of chitin, researchers at Harvard seek to substitute the compound for traditional plastic in common products.
 
The research team is interested in chitosan because of several of its key properties. It is highly inexpensive because of its immense abundance primarily from the collection of chitinous shells discarded during the processing of shrimp for consumption. Also, chitosan-based products are both biodegradable and sensitive to their environments. Once returned to the earth, chitosan-based products degrade within two weeks and are particularly sensitive when exposed to moist soil and the right set of microorganisms. In fact, chitosan-based products actually promote a healthier environment because as the chitosan degrades, it releases rich nutrients into the soil that support plant growth.

 However, chitosan cannot yet not entirely replace polyethylene-based plastics because of its inherent limitations. For one, chitosan requires additional processing in order to be waterproofed. The polymer is also not yet quite as sturdy and diversifiable as industrial polyethylene. Despite these shortcomings, chitosan does have serious potential to rival plastic materials in the mass manufacturing of everyday products like toys, toothbrushes, and chess pieces. Should manufacturers increase their use of chitosan in place of plastic, they would have immediate, profound effects on the environment, the plastics production industry and the petroleum industry.

Recently, the E.U. pledged
to reduce its carbon footprint by 40% by 2030. In order to reach this objective, many steps must be taken to lessen the EU's environmental impact. Using chitosan-based products instead of traditional plastics is a practical and realistic mechanism through which the E.U. can begin its efforts. With environmentally conscientious policymakers at the forefront, the world will hopefully see the widespread use of chitin as a renewable source of energy and materials.