Properties prediction and design of self-healing epoxy resin combining molecular dynamics simulation and back propagation neural network

Abstract

It is difficult to synergistically improve the self-healing and mechanical properties of self-healing epoxy resin system based on Diels-Alder (DA) reversible covalent bond due to its different compositions. In this study, a method combining molecular dynamics (MD) simulation and back propagation (BP) neural network was employed to achieve a balance between self-healing property and mechanical property. In addition, self-healing and mechanical properties were predicted and the influence of different compositions of the system on these properties was investigated by the BP neural network. It was found that the DA bond formed by the furan group of furfuryl glycidyl ether (FGE) and the maleimide group of bismaleimide (BMI) was of great importance for self-healing property, and that diglycidyl ether of bisphenol-A (DGEBA) with a mass fraction of 25%–48% could improve the tensile property of the system. Finally, a self-healing epoxy resin system with superior comprehensive properties was designed through the proposed method under four indexes of Young’s modulus (E), self-healing efficiency ( η ), Ultimate Tensile Strength (UTS), and glass transition temperature (Tg).

Highly Thermal Stable, Stiff, and Recyclable Self-Healing Epoxy Based on Diels–Alder Reaction

“…Figure compares the modulus and healing temperature of intrinsic SHEs synthesized via DA reaction, ,,,− disulfide exchange, − imide exchange, − and transesterification. − The moduli of almost all of these SHEs reported in the literature are less than 3 GPa, which is still far from the modulus of engineering epoxies. This is an important factor that limits the use of these SHEs in practical applications.…”

“…Therefore, these SHEs are typically used at temperatures not exceeding 120 °C. Moreover, the modulus of most of these SHEs is in the range of 1.5–3 GPa, ,,,− which is lower than that of engineering epoxy resins. It is worth noting that due to the monotonicity of these DA reactions, the healing temperature and modulus of these SHEs vary over a narrow range.…”

Self‐healing anti‐corrosion coatings: A mechanism study using computational materials science

“…This process is reversible and typically involves reverse dissociation at high temperatures. Luo et al 27 adopted a thermally reversible self-healing epoxy resin based on the DA reaction as an alternative to traditional epoxy resins and designed and optimised the resin components. As shown in Figure 2a, the simulation of the self-healing process mainly includes three steps: the disconnection of DA bonds, the rearrangement of small molecular structures, and the generation of DA bonds.…”

“…This process is reversible and typically involves reverse dissociation at high temperatures. Luo et al 27 . adopted a thermally reversible self‐healing epoxy resin based on the DA reaction as an alternative to traditional epoxy resins and designed and optimised the resin components.…”

“… (a) Simulated self‐healing process; (b) Crosslinked model of self‐healing epoxy resin; (c) Stress–strain curves of different self‐healing systems: undamaged and healed after damage; (d) Density‐temperature diagram of different self‐healing systems; (e) Storage modulus versus temperature for different self‐healing systems 27 …”