Feathering your nest with greener bio-composites

Industrial ecology can be defined as the utilization of waste products from one industry as the source/raw materials for another. It is a part of the concept of green industrialization, where as little as possible goes to waste. In this context, the millions of tons of feathers are generated by the poultry industry annually are a currently underused and undervalued resource. At present they pose a considerable and costly disposal challenge as they are either incinerated or sent to landfill. A possible solution is found in the fact that polymers reinforced with natural fibers have recently started to find use in automotive and building sectors. Such polymers can be reinforced using natural or synthetic fibers. Chicken feather fibers are an interesting candidate for the development of such new plastic bio-composites as they are lightweight, biodegradable and strong. As yet however, there has been limited development and characterization of thermoplastic polyether-polyurethane bio-composites made using chicken feathers.

Recently, a team of researchers at RMIT University, led by Professor Robert Shanks and including Associate Professor Oliver Jones and recent PhD graduate Firoozeh Pourjavaheri applied this principle to develop thermoplastic polyether-polyurethane (TPU-polyether) biocomposites with enhanced thermo-mechanical properties via the incorporation of waste chicken feather keratin as a reinforcing material. They used the entire chicken feather without any segregation in creating the new polymers making the process simple. Their work was recently published in the journal, Polymer Composites.

In brief, the research involved chicken feathers, at specific percentages, being combined with a polyurethane-based polymer to form a bio-composite. The thermo-mechanical properties of the newly made composites were assessed using thermogravimetry, dynamic mechanical analysis, and stress–strain measurements with hysteresis loops. The researchers then investigated the uniformity of the dispersion of the feather fiber in the polyurethane matrix. Lastly, scanning electron microscopy of fracture surfaces was used to verify that the adhesion between fiber and polymer was effective.

From the aforementioned measurement techniques, effective adhesion with no agglomeration coupled with an even distribution of fibers, that reflected the compatibility between the chicken feather fibers reinforcement and the TPU matrix, was demonstrated. The authors also noted that addition of the chicken feather fibers to the TPU-polyether increased the mass loss but decrease the remaining char ratio. Moreover, the feather fiber enhanced the heat resistance of the bio-composite.

In summary the study by RMIT University scientists presented the successful preparation of polyurethane ether-keratin fiber bio-composites with improved thermo-mechanical properties by blending chicken feather fibers with TPU-polyether through a solvent, casting evaporation technique. Generally, reinforcing the polymer with chicken feather fibers not only made the TPU-polyether stiffer but also reduced the deformation of the bio-composites. Dr Pourjavaheri, whose PhD research was part of the project, said  in a statement to Advances in Engineering “Using feathers in bio-composites is exciting as it could both reduce the amount of feather waste and led to creation of new products” Associate Professor Oliver Jones adds that “The bio-composites produced have, potentially, large environmental benefits, since they use keratin derived from what is currently a waste product from the poultry industry to effectively and cheaply improve the thermo-mechanical properties of composite materials”.

If the team can divert even some of the thousands of tons of waste chicken feathers from landfill it will be a positive step; creating a new range of materials as well would be even better. It is hoped this work may have people flocking to feather based solutions as part of sustainable development and industrial ecology in the near future.