The Glass Transition of Wool: An Improved Determination Using DSC
1997
Kure, Julie M. | Pierlot, Anthony P. | Russell, I. M. | Shanks, Robert A.
The glass transition temperature (Tg) of wool and its dependence on water content is reinvestigated using differential scanning calorimetry (dsc). Previous studies with dsc have not accounted for the influence of thermal history, which may introduce a large variability in Tg measurements. Because the Tg of wool is an important parameter affecting textile performance and properties, it needs to be clearly defined. When the finite volume of the water-impenetrable phase is taken into account, an important correction of the Fox equation is obtained, describing the dependence of Tg on water content. On melting of the water-impenetrable crystalline regions, a reduction in the temperature range of the glass transition region is apparent, suggesting that the crystalline regions behave in a manner analogous to filler particles in rubber. The ratio of the change in heat capacity at the glass transition, before and after melting, may provide a way to estimate the crystalline weight fraction in native wool.
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