Читать книгу The Rheology Handbook - Thomas Mezger - Страница 68

When shearing, a certain number of macromolecules are oriented into shear direction. For some of them, this results in partial disentanglements. As a consequence, viscosity decreases in these parts of the volume element. Simultaneously however, some other macromolecules which were already oriented and disentangled in the previous time interval are recoiling and re-entangling now again. This is a consequence of their visco-elastic behavior which the polymer molecules still are able to show under the occurring low-shear conditions. As a result, viscosity increases again in these parts of the volume element.