RHEOLOGICAL BEHAVIOR OF CELLULOSE MONOHYDRATE OF N-METHYLMORPHOLINE N-OXIDE SOLUTIONS - PART 1 - LIQUID-STATE/

Steady-state and dynamic experiments have been performed on solutions containing cellulose dissolved in monohydrate of N-methylmorpholine N- oxide (NMMO). The dependence of the zero-shear viscosity eta(0), and o f the terminal relaxation time tau(c), on concentration, average degre e of polymerization (<(DP)over bar>) and temperature are discussed. Th e behavior of this semi-rigid, polymolecular polymer in solution diffe rs from that of flexible monodisperse ones. The slope of the plot of l og (eta(0)) versus, on the one hand, log (c) at fixed molecular weight (<(DP)over bar>)=600, and, on the other hand, log (<(DP)over bar>) at fixed concentration (c=5% w/w) are equal to 4.6 and 5 respectively, i nstead of 3.4 in the concentrated region. Experimental data for the sh ear modulus were fitted using the classical Doi-Edwards equation with a log normal distribution of relaxation time. This distribution is com pared to the distribution of DP.