PHYSICAL-PROPERTIES AND DYEABILITY OF NAOH-TREATED SILK FIBERS

Domestic (Bonbyx mori) and wild (tussah, Antheraea pernyi) silk fabric s were treated with diluted NaOH solutions by the pad/batch method. Th e equilibrium moisture regain of tussah silk fibers increased steadily with alkaline treatment, while that of B. mori did not change. B. mor i tensile strength and elongation at break were slightly impaired. The average molecular orientation and crystallinity of both kinds of silk remained unchanged. Differential scanning calorimetry (DSC) and therm omechanical analysis (TMA) showed that the thermal behavior of B. mori silk was almost unaffected, while that of tussah exhibited slight cha nges in the temperature range 250-300 degrees C. By dynamic mechanical measurements (DMA) it was elucidated that both storage and loss modul i of B. mori silk fibers decreased following NaOH treatment. On the ot her hand, tussah silk exhibited a noticeable upward shift of the major loss peak. Alkali-treated tussah silk fibers, dyed with an acid dyest uff, attained a lower degree of dye-bath exhaustion. (C) 1995 John Wil ey and Sons, Inc.