The Importance of Rheology in the Processing of Rubber. 1. Rheological Investigations of Rubber Solutions
Abstract Using the mastication of rubber as an example, it is shown how rheology can be utilized, even in the industrial processing of macromolecular substances, to obtain, from an easily and quickly determined flow curve, a value dependent on the weight average molecular weight, and a numerical value for the polymolecularity. Solutions of chain macromolecules with a sort of Gaussian molecular weight distribution give a symmetrical flow curve with an inflection point which, as the velocity gradient which is independent of the concentration, is a function of the average molecular weight. At the same time the slope of the linearized flow curve provides a numerical value for the polymolecularity of the material in question. In this way, even those changes in a macromolecular substance which occur during factory processing can be measured, as is the case here with masticated rubber.