Rheological Properties and Gelation of Aqueous Cellulose−NaOH Solutions

Abstract

The shear rheology of a microcrystalline cellulose dissolved in a 9% NaOH aqueous solution was studied in the steady and oscillatory modes. The cellulose−(9% NaOH−H₂O) mixtures show not to be true solutions. In the dilute regime, with cellulose concentration below 1%, the rheological behavior is typical of the one of suspensions. The formation of cellulose aggregates is favored when temperature is increased. In the semidilute regime, an irreversible aggregate-based gelation occurs, being faster with increasing temperature.