Bioplastics Reinforced With Paper-Derived Nanoparticles Show Higher Durability

Researchers say the approach produces stronger, more flexible, and biodegradable alternatives to conventional soy-based plastics.

By Karl Hille

Source Baltimore Sun (TNS)

Oct. 7, 2025

3 min read

In his lab, professor Marcus Foston of Washington University’s McKelvey School of Engineering and Applied Science, inspects a bioplastic sample with Ph.D. student Jerry Wang, right. (Jerry Naunheim/Washington University in St. Louis/TNS)

Strengthening materials made from soy proteins could offer better alternatives to petroleum-based plastics, according to researchers developing practical solutions to reduce plastic pollution.

Marcus Foston, professor of energy, environmental, and chemical engineering at Washington University in St. Louis, led a team that developed a new process using byproducts from soybean oil, paper, and biodiesel production to create stronger, more flexible plastics.

“Plastic pollution is a growing problem,” Foston said. “Plastics aren’t really recycled. By 2050, there will be more plastic mass in our oceans than fish.”

The United Nations Environment Program reports that about 20 million tons of plastic waste leak into the world’s rivers, lakes, and oceans every year. These plastics degrade ecosystems and threaten food production from fishing as well as other livelihoods. According to a study by the National Oceanic and Atmospheric Administration (NOAA), microplastics have been found throughout the Chesapeake Bay and its tributaries. Microplastics accumulate in predators such as crabs and rockfish, which are popular foods for Marylanders and visitors.

“We need better replacements for plastic that are more sustainable in the long run,” Foston said. He directs the Synthetic Biology Manufacturing of Advanced Materials Research Center (SMARC) at McKelvey, which aims to enable scalable and sustainable alternatives to traditional plastics.

The road to biodegradable plastics, however, is not without challenges.

Soy proteins left over from soybean oil production can be formed into a variety of plastic packaging, but the material is very brittle. Adding glycerol — a byproduct of biodiesel production — improves flexibility, but also reduces strength.

In Foston’s latest paper, published in Polymer Composites, his team describes how plant-based particles left over from paper production can reinforce the soy-based material “in a similar way as rebar is used to reinforce concrete.”

While any fibrous plant material can be used, the process involves stripping out larger molecules by treating the fibers with acid and heat. This releases natural nanoparticles or microscopic bits of cellulose, the material that gives strength and structure to trees.

The resulting hardened material remains biodegradable but is reported to have three times the strength and flexibility of conventional soy-based plastics.

While petroleum-based plastics will likely continue to dominate the market in the near term, Foston emphasized the urgency of developing alternatives due to pollution and the finite nature of fossil fuels.

“This is something I’m really passionate about,” he said. “We like to think deeply about how we can develop technology that helps the environment.”