Surface acetylation of bamboo cellulose: preparation and rheological properties

In this study, purified bamboo cellulose was used to synthesize cellulose diacetate (B-CDA). The synthesis was controlled by determination of the degree of substitution and insoluble residue content. The product then was characterized by FTIR. The rheological properties of B-CDA solutions in acetone/N,N-dimethylacetamide (DMAc) solvent system were systematically investigated on an advanced rheometer, including the dependence of apparent viscosity η(α), non-Newtonian index n, and structural viscosity index Δη on the concentration and temperature of the solutions. B-CDA-acetone/DMAc solution is a shear-thinning fluid. With increasing solution concentration and decreasing temperature, Δη increased, whereas n decreased, which indicates a deteriorating spinnability. Moreover, the values of the viscous flow activation energy E(η) based on the Arrhenius equation increased when the shear rate γ was enhanced, which indicates that the η(α) of the solution is more sensitive to temperature in the higher γ values. The results are favorable for predicting the B-CDA solution spinnability.