A Virginia Tech professor is investigating ways to create biodegradable plastics from agricultural by-products such as poultry feathers and eggs that would be comparable to petroleum-based plastics. Scientists at Clemson University’s Animal Co-Products Research and Education Center are doing similar research using animal proteins such as feather meal, poultry meal, and blood meal (see “ACREC Solutions” in the April 2007 Render).
Biodegradable polymers created from such animal by-products may add value to the poultry industry and help solve the growing environmental problem of plastic waste. The U.S. Environmental Protection Agency estimates more than 29 million tons of non-biodegradable plastic waste ends up in landfills each year.
According to Justin Barone, associate professor of biological systems engineering in Virginia Tech’s College of Agriculture and Life Sciences, the technology to create biodegradable plastics from biomass, such as corn and soybeans, has been around for more than 70 years. However, the recent push to increase energy production from these feedstocks has increased the value of these agricultural commodities, making products made from them more expensive.
Barone has turned his focus to the agricultural waste stream and is concentrating on developing ways to use under-utilized by-products or agricultural waste, such as poultry feathers or eggs that don’t pass inspection. He explained that the challenge in developing biodegradable plastics is creating a product as good as, if not better, than its petroleum counterpart.
Plastics made from biomass are made just like petroleum-based plastics. They are cheaper to manufacture and meet or exceed most properties except for water resistance and longevity. Meeting these performance requirements is a challenge, Barone explained.
Taking his lead from nature to find potential solutions to these performance requirements, Barone is investigating the properties of polymers created from poultry-feather keratin. He has found that altering the amino acid structure of keratin can improve the strength and longevity of the polymer. In addition, the viscosity can be improved with reducing agents such as sodium sulfite and lubricants such as poultry fat. The solid-state properties can also be modified using divalent transition metal ions to affect stiffness and smell. These will help the keratin polymer be processed faster, be more aesthetically pleasing, and become water resistant and stronger for increased longevity.
Barone’s research is funded by the U.S. Poultry and Egg Association.
August 2007 RENDER | back