The Plastic State

Abstract

Abstract In the preceding article, Bary has shown a curve of the changes with time in rubber solutions of various concentrations, the interesting feature of which is the angular break which separates the curve into two sections. In a discussion of this paper, attention was called by de Meeus to the fact that it would be interesting to study the physical properties of rubber solutions as a function of the concentration without the complicating effect of aging. This brings up the question whether this curve would also have a similar break. Though data are not available on rubber solutions, it is considered that this is rendered probable by the following facts. Rubber solutions are true solutions or pseudo-solutions at great dilutions, while they become plastic at high concentrations. Experiments with certain plastic systems have shown a phenomenon which is characterized by the accompanying curve. A study of the physical properties of systems formed of various pigmente in suspension in unoxidizable oils, as a function of the concentration, showed that, in general, the properties change uniformly and continuously with increase in concentration of the pigment until a point is suddenly reached where a very pronounced break in the curve occurs.