2. Materials and methods
2.1. Material and chemicals
FS was collected following the process for retting flax stems
from the Keshan Flax Fiber Plant, Heilongjiang, China. The FS was
washed with tap water four times to remove dust and other impurities
and then air-dried. RR228 was kindly offered by Ciba Company.
Epichlorohydrin and triethylamine were purchased from Kemiou
Chemical Reagent Co. Ltd. (Tianjin, China). All other chemicals and
reagents used in this work were of analytical grade.