Glass-Transition Temperatures of Polyamide Textile Fibers

Analysis of the detailed dynamic mechanical spectrum in the vicinity of the glass-transition temperature (T _g ) of a series of polyamide textile fibers allows the prediction of their relative dyeabilities with a disperse dye, Celanthrene Fast Blue 2G, to an accuracy of about 1 K/S unit. The technique is sensitive enough to account for dyeing variations caused by annealing treatments or by drawing variations, as well as those caused by differences in molecular structure. From the position of the maximum in tan? as a function of temperature in a dynamic mechanical experiment, one definition of the T _g , it is possible to estimate semi-quantitatively whether or not a fiber will be dyeable at 100°C without carrier. In general, fibers whose T _g at 100% RH, as defined here, occurs at or below 100°C can be dyed to at least moderate shades without carrier.