Investigation on Microscopic Morphological Variation of Epoxy Adhesives by Dissipative Particle Dynamics Simulations

Abstract

Epoxy structural adhesives are widely used in various industries due to their excellent chemical resistance, thermal properties, high electrical insulation performance, increased joint stiffness, and potential for lightweighting in structural components. While the performance of epoxy adhesives is influenced by various factors such as chemical structures and compositions, it is challenging to analyze the structural morphology of epoxy adhesives at the molecular level. Therefore, in this study, we investigated macroscopic structural changes in epoxy adhesive materials based on the changes of components using dissipative particle dynamics (DPD) simulations. By calculating DPD parameters and simulating the degree of affinity interaction between the epoxy components, we represented the morphological characteristics according to their chemical structure. Through DPD simulations, we analyzed the number density, density field distribution, and diffusion coefficient of structure for each epoxy compositions, revealing that 3,3'-diamino diphenyl sulfone (3,3'-DDS) strongly interact with triglycidyl aminophenol (TGAP) and diglycidyl ether of bisphenol A (DGEBA), and polyether sulfone (PES) has repulsive interaction with TGAP, resulting in significant phase separation.