Elongational and shear rheology of cellulosic and lignocellulostic solutions in N-methylmorpholine oxide monohydrate

摘要

Elongational and shear rheology of solutions of cellulosic and lignocellulosic materials in N-methylmorpholine oxide monohydrate (NMMO) was investigated for a variety of parameters. Both effective elongational and shear viscosity show a "thin-ning effect". A strong orientation effect was noticed by calculating the body forces, enthalpy and entropy of orientation. This is particularly significant at low temperatures and high deformation rates. Also, another common trend for cellulosic and ligno-cellulosic solutions in NMMO is the transition at about 90 deg, as revealed by tan delta-temperature plots at different frequencies in Dynamical Mechanical Analysis measurements.