The dynamic mechanical loss in α-keratin fibers such as wool and horse hair can be measured by the phase difference “φ” between the oscillating extension applied to the fiber and the resultant oscillatory force. When the environment of a fiber is changed from dry to more moist conditions, the value of φ has a maximum at the point in time when the swelling of the fiber reaches a maximum. This phenomenon parallels others already observed and confirms the general picture that during sorption the molecular structure of a keratin fiber has a maximum mobility. It follows that any applied deformation at this stage will reach structural equilibrium in the shortest time.
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References
1.
FeughelmanM., A Note on Mechanical Weakening in a Stretched Wool Fiber During Moisture Sorption, Textile Res. J.32, 788–789 (1962).
2.
FeughelmanM.RobinsonM. S., A Note on the Diffusion of Water into a Dry Keratin Fiber, J. Appl. Polym. Sci.1, 371–372 (1959).
3.
HalyA. R.FeughelmanM., Stress Changes at Constant Strain and Hydrogen Bonding in Keratin Fibers, J. Textile Inst.51, T573–T588 (1960).
4.
MackayB. H.DownesJ. G., The Effects of the Sorption Process on the Dynamic Rigidity Modulus of the Wool Fibers, J. Appl. Polym. Sci.2, 32–38 (1959).
5.
NordonP., Some Torsional Properties of Wool Fibers, Textile Res. J.32, 560–568 (1962).
6.
ShishooR., Load Deformation Behavior of Wool at High Temperature in Different Media. Part I: Creep of Wool Fibers and Yarns in Steam, Textile Res. J.42, 33–44 (1972).
7.
ShishooR.LundellM., NMR Studies of Cotton and Wool in Sorption Process, Textile Res. J.42, 285–291 (1972).
