Following of polymerization process of polyurethane spinning solutions in dimethylformamide by means of the power consumption

The objective of this paper is to present the investigations of the synthesis of polyurethane (PU) spinning solutions in dimethylformamide (DMF) controlled by means of the power consumption. Power input to the mixed bulk for the two-type synthesis of polymerization process was measured in a reactor composed of multi-ribbon agitators. For these cases, the mixing power, speed rotation, temperature and mass of the reactor bulk were measured. The resultant density of mixer bulk at time duration of polymerization process was calculated using the mass and volume of reactionary mass. Based on the experimental data for the different Newtonian and non-Newtonian fluids, the analytical relationship was proposed for determination of relation between power number and Reynolds number. The flow curves of the obtained polyurethanes (PUs) from the synthesis were determined using a rotational stress-controlled rheometer and the obtained results compared with a earlier experimental data given in reference Lobanova et al. [G.A. Lobanova, V.Z. Volkov, A.I. Sokolova, Fibre Chemistry 13 (6) (1982) 399–401]. Temporal changes of the apparent viscosity of reactor bulk were obtained by shifting the power number results to the power characteristic curve and calculated from the appropriate Reynolds number. It is observed that the relationship between these dimensionless numbers may be presented in the simulation form of non-stationary power characteristics.