Rheological properties of oligoisoprene liquids. Presentation in the framework of the Angell’s concept

Abstract

The work is devoted to the study of self-organization processes in disperse systems. The most relevant aspect of such self-organization is the relationship between structure and properties in polymer composites. In this paper, we are talking about dispersion media (matrices), namely, the mechanisms of phenomena and interactions that occur during the deformation of disperse systems. These interactions depend on the properties and processes of self-organization of dispersion media and determine the properties of future polymer composites. One of the most popular dispersion media are diene oligomers (liquid rubbers). In this work, the rheology of diene oligomers with terminal hydroxyl groups (HRD) was studied in a wide range of shear rates and temperatures. It was assumed that in the case of oligoisoprene, an increase in the activation energy of viscous flow (from 46 to 95 kJ/mol) with decreasing temperature is associated with an increase in the density of the fluctuation dynamic structure with an increase in the volume content of associates of polar OH groups (i.e., nonionic micelles) with a decrease in thermal energy kT (k is the Boltzmann constant). The results of rheological studies for the first time (for non-ionic liquids) were presented within the framework of the Angell’s concept, from which it followed that these systems are fragile, i.e. they are very promising in terms of studying structure formation in a shear field.