Coarse – grained molecular dynamics simulation of cross – linking of DGEBA epoxy resin and estimation of the adhesive strength

Abstract

In this work we attempt to predict the work of separation of crosslinked diglycidyl ether of bisphenol (A) (DGEBA) adhesive confined between two rigid adherends. To this end we start from merely the molecular structure of DGEBA and coarse grain the molecule into a chain comprised of three superatoms. These three superatom structures are then allowed to crosslink (based on the attainment of a minimum distance of approach) with a coarse grained crosslinker molecule in a Molecular Dynamics (MD) simulation. The crosslinked samples, confined between rigid walls and subjected to slab boundary conditions are pulled apart at a high rate of strain to complete separation. The energy expended in causing complete separation is compared with Linear Elastic Fracture Mechanics estimates and experimental determinations of the work of separation. Our predictions of the value of the work of separation, obtained from only a description of the molecular architecture of DGEBA and the crosslinker molecule, falls within the range of scatter in the experimental measurements.

Keywords: Molecular Dynamics, Coarse – Graining, Cross – linking, Adhesion Energy