Crystallinity determination of native and stretched wool by X-ray diffraction

A quantitative study on α–β transition of Merino wool upon stretching has been carried out by wide angle X-ray diffraction using Merino wool fibre bundles. Technical factors affecting this determination, such as subtraction of air scattering and the measurement of crystallinity are considered. The degree of crystallinity has been found to be around 18% and 14% for native Lincoln and Merino wool, respectively, lower than that reported in the literature. Possible reasons for this lower value are discussed. However, the total crystallinity remained almost constant for wool samples stretched to 0, 18, 33, 49 and 66%, supporting the concept of a direct α–β transition.