DGEBA and MTHPA Crosslinking Reaction Process Analysis

Epoxy resin (EP) is widely used in various fields because of its excellent physical and chemical properties. Molecular simulations are increasingly used in epoxy resins to study their internal actions and predict their properties. However, the current research has neglected the process of crosslinking reaction, and the specific situation of crosslinking pairing and product between molecules is not clear. In this paper, monomer molecular models of EP DGEBA and crosslinking agent MTHPA were established. The distribution of atomic charge and molecular electrostatic potential were calculated, and the reactions of atoms and groups in the crosslinking were analyzed. The results show that there is little difference between the negative electrostatic potential, the positive electric potential increases from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.043 \text{Ha} / \mathrm{e}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.096 \text{Ha} / \mathrm{e}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.054 \text{Ha} / \mathrm{e}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.107 \text{Ha} / \mathrm{e}$</tex>, respectively. The maximum points of positive charge are located at the hydrogen atom on the oxygen atom, and the maximum points of negative charge are located at the oxygen atom. The hydroxyl oxygen atom of DGEBA is easy to attack the carbon atom in the aldehyde group of MTHPA, and then form the ester group.