Evaluation of rheological behaviour of some thermoplastic polyurethane solutions

In this paper some rheological properties of two type of thermoplastic poly urethane elastomer solutions are presented. For preparation of these soluti ons we utilized dimethylformamide as solvent. The concentration values and temperature of the polyurethane solutions was ranged between 7% and 15%, an d respectively 30-60 degreesC. Rheological measurements were effectuated wi th a rotating viscosimeter (Rheotest-2. Germany). Processing of experimenta l results give off the material constant value (k) and the extremities visc osity (eta (0) and eta (proportional to)). These values were verified with some rheological models. Interpretation of theological properties by Cross model proof that the solutions belong to the pseudoplastic category (viscos ity decreasing with increasing shearing rate). (C) 2001 Elsevier Science Lt d. All rights reserved.