Tensile Properties of Aromatically and Aliphatically Modified Wool Fibers Under Alkaline Conditions as a Function of Temperature

Abstract

The effect of temperature and pH on the tenacity, elongation at break, initial modulus, yield point, and yield slope was studied for untreated raw wool fibers, acetylated wool fibers, and phenylisocyanate treated wool fibers immersed in water. The mechanical property data is interpreted in terms of the temperature and pH dependence of the formation of lanthionine and lysinoalanine in the untreated raw wool, the stabilization of the cystine linkage and inhibition of lysinoalanine formation in the phenylisocyanate treated wool, and the lack of cystine stabilization and inhibition of both lysinoalanine and lanthionine formation in the acetylated wool. In addition, the influence of the α-β transition of the keratin structure on yield behavior is discussed.