A new biomaterial could save our oceans from plastic pollution

Straws, water bottles, shopping bags, cups, utensils: so many of these everyday objects are made from single-use plastics, i.e. they are used only once and then thrown away. As a result, these items often end up in landfills and waterways, where they not only suffocate and trap wildlife, but also release harmful toxins into the environment as they decompose.

Now, NC State researchers have developed a new biomaterial that could help solve the growing problem of plastic pollution. Friend of Lokendra and Lucien Luciaprofessors in the Department of Forest Biomaterials, discovered how to convert leftover sawdust powder and agro-residues into polystyrene-like packaging material.

The wood-based material could one day replace the plastics found in many single-use items. With support from the Chancellor’s Innovation Fund, Pal and Lucia are currently conducting pilot trials, ahead of testing and commercialization by potential industry partners. They mainly focus on manufacturing packaging and catering products.

Lokendra Pal (center) examines samples of the biomaterial in her on-campus lab. Photo by Becky Kirkland/NC State.

Packaging and catering products are often made from polystyrene, a popular brand of polystyrene, which is a petroleum-based plastic. Because polystyrene foam is non-recyclable and non-biodegradable, these products are quickly thrown away and end up in landfills and waterways, where they can take 500 years to decompose.

“Polystyrene items are not used for very long before they are thrown away. But they pose a major threat to human and ecosystem health,” Pal said. “The lightweight composition and buoyancy of polystyrene foam allows it to float long distances in water. It can also absorb and transport toxic pollutants, such as mercury.

More than 300 million tonnes of plastic are produced each year, half of which is used in single-use items. Research shows that about 12 million tons of this waste enters the ocean every year. Unfortunately, if plastic production and disposal continues at the current rate, this amount will almost triple to 30 million tonnes per year by 2040.

Biomaterial samples - A new biomaterial could save our oceans from plastic pollution - College of Natural Resources News - NC State University
Pal and Lucia created several proof-of-concept pieces from their new biomaterial, including LEGO bricks and chess pieces. Photo by Becky Kirkland/NC State.

In an effort to combat plastic pollution, researchers around the world have developed alternatives made from biopolymers and fibers. These alternatives, however, require a lot of water, energy and chemicals to produce and therefore cost almost 10 times more than the material developed by Pal and Lucia.

Pal and Lucia have developed a production process that does not require water. Instead, researchers sieve, grind and mechanically mix sawdust – a low-value by-product of wood manufacturing and processing – with agro-residues to form a powder. The powder is then combined with a binder before being cast or molded into an article.

Additionally, because the researchers use sawdust, the production process is virtually waste-free and emission-free. Sawmills and similar operations usually dispose of their leftover sawdust by burning it. This not only ends the life cycle of a valuable by-product, but also produces the greenhouse gas emissions that cause climate change.

Drying biomaterial samples - A new biomaterial could save our oceans from plastic pollution - College of Natural Resources News - NC State University
Once the biomaterial has been cast or moulded, the articles must be dried. Photo by Becky Kirkland/NC State.

“Our research has had a strong focus on environmental and economic sustainability,” Pal said. “We know that this material is not only recyclable and compatible with the environment, but also biodegradable in salt water. It will simply disappear over time and therefore provide nutrients for aquatic life.

Pal added that the material also addresses social equity, reducing the impact of plastic pollution on marginalized communities around the world. Research shows that plastic pollution is more heavily concentrated along the coasts of low- and middle-income countries, which already have poor waste management systems.

Ultimately, as Pal and Lucia conduct pilot and commercial trials of their material over the next six months, they plan to further test its biodegradability and biocompatibility and scale up production for industrial partners. Researchers will also explore the use of 3D printing in the production process, with the goal of eventually creating environmentally friendly household items.

This post was originally published in College of Natural Resources News.

Bryce K. Locke