The Differential Thermal Analysis of Natural and Modified Wool and Mohair

Abstract

Four types of wool and three types of mohair were examined by differential thermal analysis (DTA) in the natural and dried states. The DTA curves of wool and mohair were not significantly different. Curves for both in the natural state showed an endotherm at 130–145°, ascribed to the vaporization of bound water, and endotherms at 220–230° and 230–250° accompanied by charring, the release of gaseous decomposition products, and, ultimately, liquefaction. Derivatives of one type of wool and one type of mohair prepared by acetylation or modification of the disulfide cross-linkages were compared with unmodified materials by DTA. Differences in the DTA curves are described, and possible correlations of these with the changes in chemical structure are suggested. Collagen, gelatin, silk, horn keratin, cystine, and cysteine hydrochloride were also characterized.