3.7. Desorption properties of lac dye from the dyed chitosan fiber in
water
The healthy and hygienic textiles prepared by chitosan fiber are
subjected to frequent washing during their usage. Hence the resistance
of functional lac dye on the textiles to washing is very important.
In the present study, the washing resistance was tested
through the desorption of lac dye from the dyed chitosan fiber in
water at 50 C. As seen in Fig. 10, the desorption rate of lac dye
was extremely low, and did not exceed 2%, although it increased
as the time was prolonged. The simulated washing test suggests
that the washing resistance of lac dye on chitosan fiber is very
good, indicating the excellent durability of the functionalities of
chitosan fiber provided by lac dye.