Rheology of cellulosicN-methylmorpholine oxide monohydrate solutions of different degrees of polymerization

Preparation and shear and elongational rheology of cellulose solutions of different degrees of polymerization (DP) in N-methylmorpholine oxide monohydrate (lyocell) were investigated. The dissolution process takes place in two stages, depending on the content of low and high DP fractions from the dissolving pulp blends. The influence of the DP of cellulosic chains on elongational and shear viscosity is greater at low deformation rates. Low DP solutions behave more like viscous fluids and the increase of the chain length brings about an increase of the elastic component. Orientation induced by the convergence flow is enhanced by the higher DP cellulosic chains. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 396–405, 2001