Researchers unveil new polymer technologies in Chicago

A chemist based in Blacksburg, Va. is investigating ways to make biodegradable plastics using agricultural waste from the poultry industry.

Justin Barone, an associate professor of biological systems engineering at Virginia Tech, is creating plastic polymers using the keratin protein from poultry feathers that are comparable to traditional petroleum-based plastics. Barone presented his research at the 233rd American Chemical Society National Meeting in Chicago, Ill. last week.

In an interview with Canadian Plastics, Barone said the polymers are made using keratin from feathers, a plasticizer, crude glycerol from biodiesel, and sodium sulphite as a reducing agent. The protein-based and fully biodegradable polymers have been extruded into clear plastic film, and pelletized for use in injection molding applications.

The product is currently being refined, with attempts to create a line of aesthetically pleasing polymers that have high stiffness and high flexibility.

The focus of Barone’s research was on creating a product that can be processed in the same way as crude-based resins.

“Even the commercial biodegradable products [like PLA] have enormous crystallization times, and it’s difficult to have reasonable cycle times,” noted Barone.

The keratin-based polymers are almost ready for commercialization, and Barone said the product would mainly be aimed at the mass consumer products industry.

“We are targeting applications that are high volume and will end up in a landfill one day, so you are mostly talking about packaging,” explained Barone.

The keratin polymers would also be of great use in the agricultural industry, such as in the manufacture of plastic-based plant pots.

“The horticulture industry is using an enormous amount of plastic, and all of the plastic has to get landfilled, recycled or thrown away,” said Barone. “This is a really great application because the industry is located in rural areas, where they might be a lot of chicken feathers that they can turn around and compost.”

Attendees at the American Chemical Society National Meeting also heard from Professor Robson Storey of Polymer Science and Engineering at the University of Southern Mississippi. Storey was a study leader for an environmentally friendly plastic that degrades in seawater. The polymer is mostly intended for applications for military, merchant and cruise ships.

Storey explained that the plastic could be used to make stretch wrap for large cargo items, food containers, eating utensils and other plastics used at sea, and may help reduce the environmental impact of plastic marine waste.

The plastics are made with polyurethane that has been modified using PLGA [poly (D,L-lactide-co-glycolide)], and the researchers have produced a range of mechanical properties for different applications.

These new plastics degrade into nontoxic products via hydrolysis when they are exposed to seawater.

Storey noted that the plastics are not ready for commercialization because more studies are needed to optimize the plastic for various environmental conditions. Also, the biodegradable product has not been tested in freshwater.