Study of the effect of the ratio of epoxy resin and curing agent comonomers on mechanical properties of the system: mesoscale simulation

This publication continues the cycle of our work aimed at improving the methodology for constructing mesoscale models of network polymers and characterizing their physical properties. As the object of study, the epoxy resin of bisphenol A, diglycidyl ether, and a tricarboxylic fatty acid hardener was chosen. Its structure is the result of three parallel reactions. For their correct reproduction, an algorithm was proposed, which allows to take into account the peculiarities of the relationship of all ongoing processes. The system model was constructed by mapping the chemical structure of the monomers onto an equivalent mesoscale representation. It was used to study the relationship between the structure and mechanical properties of feeding networks as a function of the ratio of volume fractions of comonomers in the initial reaction mixture. All calculations were performed within the reaction version of the dissipative particle dynamics method. The structure of polymer networks in the constructed samples was characterized by topological analysis. The study of mechanical properties was carried out by constructing the "stress-strain" dependencies. The results obtained show a good correlation between the density of the load-bearing chains and the mechanical properties of the resulting networks. It is shown that the material samples with the highest degree of transformation and the density of the number of load-bearing chains have the highest stiffness.