Crop straw resources are abundant in nature.In this study the crop straws were used as raw material for carboxymethylation after activation by steam explosion treatment.Then the high value-added carboxymethylcellulose(CMC) was separated from other components through solvent extraction according to their different physico-chemical properties.The results indicated that the best reaction condition was that the straws were carboxymethylated at 75℃ for 2 h with the liquid volume (ml)/solid mass (g)
molar ratio of NaOH/SMCA and H2O/straw (ml∶g)were 18∶1
4∶3 and 1∶2,respectively.Under the optimized reaction conditions
the yield of CMC in the products could reach 40.70%
the substitution degree (DS) of CMC obtained reached 0.91
which was similar to that prepared from straw α-cellulose
which possessed special characteristics of low viscosity.The CMC was characterized with FTIR and 1H NMR.Meanwhile
the lignin part with great industrial potential could also be separated from the products.Compared with the current utilization of high α-cellulose as raw material in the carboxymethylcellulose industry