Non-Isothermal Rotational Viscometry (An Analytical Equation for Treatment of Experimental Data)

Abstract

In the viscometry of highly viscous liquids (particularly concentrated polymer solutions and polymer melts) it is necessary to take into account heat dissipation, leading to non-isothermal flow. Thus the general treatment of a viscometric experiment must rely on a joint solution of the heat and force balance equations. Such an approach to the model of the rotational viscometer has been repeatedly discussed (see for example Refs. 1–4). For this model the possibility of hydrodynamic thermal explosion has been established 4,5. But the non-isothermal method for viscosity measurements has not been used because of the absence of simple and ready-for-use expressions for treatment of experimental data as the known formulae are too complicated.