Temperature Dependence of the Rheological Properties of Acetoxypropylcellulose in the Thermotropic Chiral Nematic Phase

摘要: Abstract The rheological behaviour of two different molecular weights a thermotropic liquid crystalline cellulose derivative, acetoxypropylcellulose (APC), at T=120°C, has already been reported [1]. In this work we present the temperature dependence properties APC. shear viscosity, η, and first normal stress difference, N1, were measured temperatures T=120, 130 140°C, for M W = 94000 g/mole, T=120 140°C 129000 rates, γ, between 0.01 10 s-1. viscosity η(γ) decreases with increasing T, both samples, showing strong thinning all over whole range γ studied, except rates about 0.2 1 s-1 (depending on T), where quasi-Newtonian plateau is observed. difference N1 (γ) also T given γ. It increases rate shows an inflection a...