Submitted to: Composite Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 22, 2004
Publication Date: February 1, 2005
Citation: Barone, J.R., Schmidt, W.F. 2005. Polyethylene reinforced with keratin fibers obtained from chicken feathers. Composite Science and Technology. 65(2):173-181.
Interpretive Summary: High sales volume synthetic polymers like polyethylene are very easy and cheap to process but usually require modification of the properties to get the desired performance out of a molded component. Therefore, commodity polymers like polyethylene are usually modified by adding fibers, particles, or other polymers through melt mixing. The desired result is to increase stiffness or strength to meet the physical requirements of the intended application. Typical modification materials are inorganic materials like glass, talc, or calcium carbonate. These materials not only add strength or stiffness to commodity polymers but weight as well. This paper describes a new organic modifier obtained from poultry feathers. The modifier is keratin feather fiber. The effects of fiber concentration and length on the properties of polyethylene composites are delineated. The keratin feather fiber has a high strength and stiffness that adds to the physical properties of the polyethylene but a low density so it does not add to weight. The strength to weight ratio of keratin fibers is much closer to the strength to weight ratio of glass or other inorganic fillers than the absolute magnitude of strength.
Polyethylene-based composites were prepared using keratin fibers obtained from chicken feathers. Uniform-sized fibers of varying aspect ratio were mixed into low-density polyethylene (LDPE) using a Brabender mixing head. From uniaxial tensile testing, an elastic modulus and yield stress increase of the composite over the virgin polymer was observed over a wide range of fiber loading. Scanning electron microscopy revealed strong interactions between the polymer and keratin feather fiber. In addition, the keratin fiber had a density lower than the LDPE used in this study resulting in composite materials of reduced density. The results obtained from mechanical testing are compared to theoretical predictions based on simple composite material micromechanical models.