Comparison of rheological properties of kraft and microcrystalline cellulose dissolved in 1-butyl- 3-methylimidazolium chloride

Lahcen EL HAMDAOUI, Mahdi El Bouchti, Mohammed EL Moussaouiti, Said Gmouh

Abstract


Rheological behavior of kraft (KrC) and microcrystalline (MCC) cellulose dissolved in ionic liquid (IL) 1-butyl- 3-methylimidazolium chloride ([Bmim]Cl) were characterized using an advanced rheometer. Firstly, we studied experimentally the mass transport properties (viscosity and ionic conductivity) of [Bmim]Cl, [Bmim]Cl/DMAc and 0.25 wt% KrC/[Bmim]Cl/DMAc solutions  at different concentration of DMAc at 25 °C. Then the shear rheology of cellulose/[Bmim]Cl solutions was studied in a range of concentrations (0.25-2 wt%) and temperatures (25-80 °C). As expected, DMAc dramatically decreases the viscosity and increases the conductivity of the solutions. The viscosity of kraft cellulose of high molecular weight was higher than that the microcrystalline cellulose of low molecular weight. All KrC/IL/DMAc and MCC/IL/DMAc solutions behave as non-Newtonian fluids. The viscosity of solutions increased with increase in solution concentration. The heightening of solution temperature lowers sharply the viscosity of the solution. The activation energy of KrC is higher than that of MCC.


Keywords


Cellulose; Ionic Liquid; Rheology; Viscosity-temperature; Shear viscosity.

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