DSC investigation of the physical ageing and deageing of wool

Wool can be deaged both thermally and aqueously, resulting in disruption of the network of secondary bonds. The ensuing increase in mobility of the macromolecular chains manifests itself as a decrease in the glass transition temperature; hence this property can be used to monitor the ageing/deageing process. The extent and stability of the network that forms on ageing is a function of the temperature and time of formation. If samples are allowed to age for two consecutive periods of time at different temperatures then two independent networks are formed, each with its own characteristic glass transition temperature. The moisture content, thermal history and scan rate must be carefully controlled during any thermal analysis. It has also been shown that deageing can be used to facilitate the temporary setting of wool.