New process turns waste chicken feathers into biodegradable plastic

Nearly 3 billion pounds of chicken feathers are plucked each year in the United States -- and most end up in the trash. Now, a new method of processing those feathers could create better types of environmentally-friendly plastics.

"Chicken feathers are one of those materials that is still basically waste," said Yiqi Yang, a researcher at the University of Nebraska-Lincoln and one of the authors of the new research. Feathers are mostly made of keratin, the protein that's responsible for the strength of wool, hair, fingernails, and hooves, he added. So they "should be useful as a material."

Past efforts to create plastic from feathers resulted in products that didn’t hold up mechanically or weren't completely water-resistant, said Yang’s University of Nebraska colleague Narenda Reddy, who also worked on the project.

To make the new plastic, the researchers started with chicken and turkey feathers that had been cleaned and pulverized into a fine dust. They then added chemicals that made the keratin molecules join together to form long chains -- a process called polymerization. The team presented their work March 24 at a meeting of the American Chemical Society in Anaheim, California.

The plastic they made was stronger than similar materials made from starch or soy proteins, and it stood up to water. Moreover, high temperature treatment of the feathers at the start of the process would blast out any possible contamination, such as from bird flu, according to Reddy.

The new material is a thermoplastic. "We can use heat and melt it to make different products," said Reddy. Heating it to a modest -- for industrial manufacturing -- 170 degrees Celsius allows the plastic to be molded into some desired shape, and it can be melted and remolded many times. Unlike most thermoplastics, which are petroleum-based, chicken-feather plastic uses no fossil fuels, the researchers said.

The feather-based plastic could be used for all kinds of products, from plastic cups and plates to furniture. In addition to making use of feathers that would otherwise end up in landfills, it is highly biodegradable.

This and other new sources of plastic may signal a shift in the way people think about packaging, said Walter Schmidt, a scientist with the Department of Agriculture’s Agricultural Research Service in Beltsville, Md., who works on making a different kind of plastic from feathers. "With foods, almost everyone understands half-life and shelf-life. No one expects milk in the fridge to be good three months after purchase."

Yet we rarely think of packaging in the same way, said Schmidt. "Stuff floats around in the ocean [or] is mixed in landfills that stay there for generations. A far better solution is to make less mess in the first place and to have that material naturally recycle in a reasonable amount of time." Although feathers are known to be tough, he added, there are no archeological sites containing reservoirs of feathers, showing that they break down over time.

The usefulness of any biopolymer, like the feather plastic, depends on the cost and versatility of the end product, said Schmidt, adding that when the price of oil increases, bio-alternatives become more attractive.

As concerns over the environment and shortages of raw materials grow, creative thinking about waste products takes on greater importance. "Think of a Styrofoam coffee cup," said Schmidt. "It is used for maybe 10-15 minutes and discarded; one can dig up a Styrofoam cup from a landfill 200 years from now, wash it out, and reuse it. This is an example of a lousy design." A better design is an ice cream cone: "The container lasts a little longer than the ice cream in it."

Although more work is needed to bring the new plastic into large-scale production, chicken feathers could soon be moving from the coop to the cup.

Provided by Inside Science News Service (news : web)

Advance toward making biodegradable plastics from waste chicken features

In a scientific advance literally plucked from the waste heap, scientists today described a key step toward using the billions of pounds of waste chicken feathers produced each year to make one of the more important kinds of plastic. They described the new method at the 241st National Meeting & Exposition of the American Chemical Society, being held here this week.

"Others have tried to develop thermoplastics from feathers," said Yiqi Yang, Ph.D., who reported on the research. "But none of them perform well when wet. Using this technique, we believe we're the first to demonstrate that we can make chicken-feather-based thermoplastics stable in water while still maintaining strong mechanical properties."

Thermoplastics are one of two major groups of plastics, and include nylon, polyethylene, polystyrene, polyvinyl chloride, and dozens of other kinds. They are used to make thousands of consumer and industrial products ranging from toothbrush bristles to soda pop bottles to car bumpers. Thermoplastics got that name because they need heat (or chemicals) to harden from a liquid into a final shape, and can be melted and remolded time and again. The other group, thermosetting plastics, harden once and can't be remelted again.

Yang pointed out that both kinds of plastics are made mainly from ingredients obtained from oil or natural gas. Because of concerns about petroleum supplies, prices, and sustainability, dozens of scientific teams are working to find alternative ingredients. One major goal is to use agricultural waste and other renewable resources to make bioplastics that have an additional advantage of being biodegradable once discarded into the environment.

"We are trying to develop plastics from renewable resources to replace those derived from petroleum products," said Yang, who is an authority on biomaterials and biofibers in the Institute of Agriculture & Natural Resources at the University of Nebraska-Lincoln. "Utilizing current wastes as alternative sources for materials is one of the best approaches toward a more sustainable and more environmentally responsible society."

Chicken feathers are an excellent prospect, Yang explained, because they are inexpensive and abundant. Few shoppers think about it, but every shrink-wrapped broiler in the supermarket cooler leaves behind a few ounces of feathers. Annually there are more than 3 billion pounds of waste chicken feathers in the United States alone. These feathers can be processed into a low-grade animal feed, but that adds little value to the feathers and may also cause diseases in the animals. All too often, they become a waste disposal/environmental pollution headache, incinerated or stored in landfills.

Yang explained that chicken feathers are made mainly of keratin, a tough protein also found in hair, hoofs, horns, and wool that can lend strength and durability to plastics. Yang added that the mechanical properties of feather films outperform other biobased products, such as modified starch or plant proteins.

To develop the new water-resistant thermoplastic, Yang and colleagues processed chicken feathers with chemicals, including methyl acrylate, a colorless liquid found in nail polish that undergoes polymerization — that's the process used in producing plastics in which molecules link together one by one into huge chains. This process resulted in films of what Yang's group terms "feather-g-poly(methyl acrylate)" plastic. It had excellent properties as a thermoplastic, was substantially stronger and more resistant to tearing than plastics made from soy protein or starch, and as a first among chicken-feather plastics had good resistance to water.

Provided by American Chemical Society (news : web)

Advance toward making biodegradable plastics from waste chicken feathers

In a scientific advance literally plucked from the waste heap, scientists have described a key step toward using the billions of pounds of waste chicken feathers produced each year to make one of the more important kinds of plastic. They described the new method at the 241st National Meeting & Exposition of the American Chemical Society, being held in Anaheim, California the week of March 28.

"Others have tried to develop thermoplastics from feathers," said Yiqi Yang, Ph.D., who reported on the research. "But none of them perform well when wet. Using this technique, we believe we're the first to demonstrate that we can make chicken-feather-based thermoplastics stable in water while still maintaining strong mechanical properties."

Thermoplastics are one of two major groups of plastics, and include nylon, polyethylene, polystyrene, polyvinyl chloride, and dozens of other kinds. They are used to make thousands of consumer and industrial products ranging from toothbrush bristles to soda pop bottles to car bumpers. Thermoplastics got that name because they need heat (or chemicals) to harden from a liquid into a final shape, and can be melted and remolded time and again. The other group, thermosetting plastics, harden once and can't be remelted again.

Yang pointed out that both kinds of plastics are made mainly from ingredients obtained from oil or natural gas. Because of concerns about petroleum supplies, prices, and sustainability, dozens of scientific teams are working to find alternative ingredients. One major goal is to use agricultural waste and other renewable resources to make bioplastics that have an additional advantage of being biodegradable once discarded into the environment.

"We are trying to develop plastics from renewable resources to replace those derived from petroleum products," said Yang, who is an authority on biomaterials and biofibers in the Institute of Agriculture & Natural Resources at the University of Nebraska-Lincoln. "Utilizing current wastes as alternative sources for materials is one of the best approaches toward a more sustainable and more environmentally responsible society."

Chicken feathers are an excellent prospect, Yang explained, because they are inexpensive and abundant. Few shoppers think about it, but every shrink-wrapped broiler in the supermarket cooler leaves behind a few ounces of feathers. Annually there are more than 3 billion pounds of waste chicken feathers in the United States alone. These feathers can be processed into a low-grade animal feed, but that adds little value to the feathers and may also cause diseases in the animals. All too often, they become a waste disposal/environmental pollution headache, incinerated or stored in landfills.

Yang explained that chicken feathers are made mainly of keratin, a tough protein also found in hair, hoofs, horns, and wool that can lend strength and durability to plastics. Yang added that the mechanical properties of feather films outperform other biobased products, such as modified starch or plant proteins.

To develop the new water-resistant thermoplastic, Yang and colleagues processed chicken feathers with chemicals, including methyl acrylate, a colorless liquid found in nail polish that undergoes polymerization -- that's the process used in producing plastics in which molecules link together one by one into huge chains. This process resulted in films of what Yang's group terms "feather-g-poly(methyl acrylate)" plastic. It had excellent properties as a thermoplastic, was substantially stronger and more resistant to tearing than plastics made from soy protein or starch, and as a first among chicken-feather plastics had good resistance to water.

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The above story is reprinted (with editorial adaptations) from materials provided by American Chemical Society.