Recrystallization Behavior and Mechanical, and Carbonizing Properties of Feather Keratin Resin Sheets Produced by Hot-Compression Molding

Abstract

Resinification of milled waterfowl feathers was attempted via a conventional hot-compression molding and its resinification behavior and the physical properties of the resultant resin were investigated. The hot-compression molding using the wet feather powder was found to be effective to achieve full resinification of the feathers, suppressing its thermal decomposition. The starting milled feathers showed a halo X-ray diffraction (XRD) scattering, indicating the destruction by the milling of the four fold screw crystal structure embedded in the feather microfibrils. Fourier-transform infrared (FTIR) spectroscopic measurements revealed that the amide I peak of the pristine feathers was slightly shifted to the higher wavenumber side by milling or resinification, which means a decrease in the strength of hydrogen bonds between the adjacent β-strands. After the hot-press compression molding, a non-oriented crystalline WAXD peak was clearly recognized again, indicating the partial recrystallization of the feather keratin. The glass transition temperature of the feather keratin resin was estimated at around 120 °C from the onset of the increase of the loss modulus (E″) in the dynamic mechanical analysis (DMA) measurements. Further, it was confirmed that resinification of the milled feathers followed by the hydrothermal treatment could produce a carbonizing precursor having stacked polyaromatic carbon clusters which may be applicable to design a functional electrode.