Supramolecular structure of epoxy oligomers

Abstract

AbstractBased on the generalized results of experimental methods for studying the viscosity of oligomers—DSC, electron microscopy, NMR spin echo, x‐ray diffraction analysis, edge wetting angles, laser microinterference, atomic force microscopy, dynamic light scattering, plastic flow—an analysis of the features of the supramolecular organization of melts and solutions of epoxy oligomers was carried out. In terms of thermofluctuation approach, a qualitative assessment of the structural elements forming a macroscopic polymer body is given, and direct morphological evidence of their structure, thermodynamic stability, size evolution with temperature changes and elastic‐strain effects is presented. A mathematical apparatus has been developed to describe the destruction of domains in solutions and melts of oligomers. Analytical equations have been proposed for calculating the time of thermofluctuation relaxation of domains. Based on the analysis of the supramolecular structure of dian epoxy oligomers by transmission electron microscopy and translational mobility of oligomer macromolecules in the high temperature region (Tg + 150°C), it has been suggested that a structure such as “flickering clusters” of free volume elements is formed in the oligomer melts.Highlights Phase diagrams of aromatic and aliphatic epoxy oligomers have been constructed. The influence of molecular weight on the activation energy of diffusion of viscous flow is estimated. It has been shown that the supramolecular structure of epoxy oligomers in the melt contains “flickering clusters.” The lifetime of density fluctuations of epoxy oligomers domains in melts has been calculated.