Extension of Keratin in Ethanol at Low Temperatures

Abstract

DYNAMIC mechanical measurements on α-keratin in water¹ have recently indicated that the matrix—which becomes swollen in water—behaves like a polymer with an effective glass transition temperature probably in the region of −20° C to −30° C. In an attempt to include the presumed glass transition behaviour in the working range, further experiments were carried out on wool fibres immersed in ethanol. An unexpected feature of this work was that the extensibility in ethanol remained high (>30 per cent) even at temperatures as low as −75° C. The glass transition region was still inaccessible, and was elevated from below the freezing point of water to above the boiling point of ethanol. This communication outlines some of the results from the dynamic experiments as well as from conventional tensile tests which are of interest for the light that they throw on the structure of keratin.