Production of Feather-Based Biopolymers as a Direct Alternative to Synthetic Plastics

The diminishing supply of crude oil has led the polymer industry to continue to investigate the use of alternative polymer feedstocks. Agricultural waste streams (or low-value byproducts) often contain the building blocks for biopolymer production. One potential feedstock is poultry feathers. Global poultry production currently exceeds 50 billion birds per annum and is continuing to increase. Generating more than 6 million tonnes of feathers/keratin annually, it represents a viable resource for biopolymers. A barrier to industrial adoption has been scalability. This work aims to upscale the extrusion process by adapting to a larger extruder (capable of 3+ kg/h), which will also improve mix stability. Use of this system improved throughput to 0.8 kg/h. The pellets produced were then used in secondary processing (tube and sheet extrusion) to investigate the potential for targeted applications. Analysis on water uptake, morphology, and mechanical properties was conducted to characterize feather-based polymers. Mechanical properties (tensile strength 3.6 MPa and elongation 58%) were similar to those of other biopolymers (range between 0.3 and 10.6 MPa and 2 and 85%, respectively) yet were achieved using a lower plasticizer content (24% compared to 29–40%)/higher waste loading. Results proved that feather polymers could be produced on a large scale and used to produce a range of final applications using a material containing ∼70% waste product.