Submitted to: Journal of Applied Polymer Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/27/2005
Publication Date: 2/1/2006
Citation: Barone, J.R., Schmidt, W.F., Gregoire, N.T. 2006. Extrusion of feather keratin. Journal of Applied Polymer Science. 100(2):1432-1442. Interpretive Summary: As petroleum prices soar, researchers are searching for new feedstocks to produce chemicals and plastics. Agricultural feedstock, specifically poultry feather waste, presents a possible source. In this paper, a scheme is outlined for the high throughput extrusion of feather keratin-based polymer. This is how most plastics are processed currently. It is found that the feather keratin polymer processes similarly to many petroleum-derived thermoplastics and has solid-state properties similar to the same plastic materials.
Technical Abstract: Keratin obtained from poultry feathers was extruded at 120°C using a combination of glycerol, water, and sodium sulfite as processing aids. Rheological properties were assessed as a function of water, glycerol, and sodium sulfite content as well as extruder die temperature. The lowest viscosity blends at a constant feather keratin concentration of 60 weight percent (wt%) were found at glycerol concentrations that were higher than the water concentration and sodium sulfite concentrations of 3-4 weight percent of the feather keratin fraction. For the melt state, higher or lower sodium sulfite concentrations resulted in increased viscosity. In the solid state, it was observed that processing induced orientation increased the tensile properties of the extrudates. Raman spectroscopy and DSC showed that mostly disordered structures were formed at sodium sulfite concentrations of less than 4 wt%. At greater sodium sulfite concentration, increased crystallinity was found because keratin chains could be extended more during processing.