Water desorption from keratins

C. Popescu1,2, , P. Augustin1 and F. J. Wortmann3 1 DWI e.V. and Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Pauwelsstrasse 8, D-52056 Aachen, Germany 2 University „Aurel Vlaicu“, Bd. Revolutiei 77, RO-310130 Arad, Romania 3 School of Materials, University of Manchester, Manchester M601QD, UK We have carried out a DSC investigation under nitrogen flow of moisture desorption from wool equilibrated with various amounts of water. The recorded data have been used to calculate the kinetic parameters of the desorption process assuming a single process and within the framework of the reaction order. We found that while the reaction order and the peak temperature changes with the equilibrium water content (e.w.c.) which wool fibre had at the beginning of the desorption experiment, the activation energy and the pre-exponential factor remain fairly constant. The overall reaction rate shows that, due to the change of the kinetics of wool-water system with the change of the initial moisture content, higher the initial water content of the fibre is, faster the desorption occurs. The results point out clearly that any study of water desorption from wool should specify the initial value of the equilibrium water content.