Carboxymethylation of α-cellulose isolated from Lantana camara with respect to degree of substitution and rheological behavior

Lantana camara is a noxious weed posing a serious threat to the ecology and demands concerted efforts for its management. Utilization of its abundantly available cellulosic biomass as chemical feedstock could be a practical proposition for the management of this weed. α-cellulose (Av DP 430) was, therefore, isolated from this weed and its carboxymethylation was studied under varying reaction conditions with respect to maximum DS. The influence of reaction conditions on apparent viscosity of the prepared derivatives was also studied. The conditions optimized were concentration of aqueous NaOH 3.24 mol/AGU, 20% (w/v); concentration of MCA 2.05 mol/AGU; carboxymethylation time 3.5 h and temperature 55 °C with isopropyl alcohol as the solvent medium to yield CMC of DS 1.22. Rheological studies of 1 and 2% solutions of the optimized product showed their non-Newtonian pseudoplastic behavior.