2.1.3. Cotton pretreatment with chitosan
Chitosan (medium molecular weight, viscosity 200.000 cps,
CAS 9012-76-4, FW of repeating unit, 161) was purchased
from the Aldrich Chemical Company. A 1% (w/v) stock
solution of chitosan was prepared by dissolving the required
amount of chitosan in a 1% (v/v) aqueous acetic acid solution.
The cotton yarn (50 g), prepared as noted in Section 2.1.1., was
then immersed directly in 0.3% and 0.6% (v/v) aqueous
solutions of chitosan (2 L) (prepared from the stock solution)
at room temperature for 1 h. After this time the yarn was
removed and dried at 100 C for 30 min and then cured at
160 C for 10 min. The cotton yarn, after pretreatment with
chitosan, was rinsed with water at 40 C and allowed to dry
in the open air in the laboratory.