Tough plastic film made from waste chicken feathers
By Ben Coxworth
April 4, 2011
At last week's 241st National Meeting & Exposition of the American Chemical Society, a number of institutions presented their research into possible new sources of eco-friendly bioplastic, including everything from fruit fiber to bone meal. On the final day of the event, one other idea was put forward – bioplastic made from waste chicken feathers. While this particular source material has been tried only semi-successfully in the past, the researchers claim that this time, the chicken plastic should take flight.
Dr. Yiqi Yang, from the Institute of Agriculture & Natural Resources at the University of Nebraska-Lincoln, explained that chicken feathers are ideal for use in bioplastics, as they are both plentiful and inexpensive. The U.S. alone currently generates more than 3 billion pounds (1.36 billion kg) of chicken feathers annually, with most of those either being processed into low-grade animal feed, or simply discarded.
The feathers are mainly composed of keratin, the same tough protein found in animal hoofs and horns. Thermoplastic film made from keratin is said to have excellent mechanical properties, exhibiting better strength and tear-resistance than plastics made from other biological sources such as modified starch or plant proteins.
Previous bioplastics made from feathers, however, have proven not be very water-resistant. Yang addressed this shortcoming by processing feathers with polymerizing chemicals including methyl acrylate, which caused the plastic's molecules to link together into long chains. The result was what Yang and his team call "feather-g-poly" plastic – not only is it strong, he claimed, but it can also be melted down and reused like other thermoplastics, and has good water resistance.