Viscosity-temperature relationships for dilute solutions of cellulose derivatives: I. Temperature dependence of solution viscosities of ethyl cellulose
Affiliation:
1. Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Polytekhnicheskaya Street, 29, 195251, Russia;2. Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India;1. Department of Mechanics, University of Novi Sad, Serbia;2. Department of Otorhinolaryngology, University of Novi Sad, Serbian
Abstract:
Viscosities of dilute solutions of six fractions of ethyl cellulose, molecular weight range 40,000–140,000, in six solvents have been determined at different temperatures between 25° and 60°C. Log η is very approximately a linear function of the reciprocal of the absolute temperature T. Values of Q and A in the expression η = AeQRT role=presentation style=font-size: 90%; display: inline-block; position: relative;> are obtained. The apparent activation energy of viscous flow, Q, is linearly related to concentration c and molecular weight M by Q = Q0 + KeMc and A = A0e−KaMαc where Q0 and A0 are values for the pure solvents and Ke, Ka, and α are constants for a particular ethyl cellulose-solvent system. The values of Ka and α may vary slightly with M. An expression is derived giving the intrinsic viscosity in terms of Ke, Ka, α, M, and T.
