Elucidation of the Adhesive Interface Formation Mechanism of Polymeric Materials with Reversible Cross-linking through All-atom Molecular Dynamics Simulation

A reversible crosslinking structure composed of guest molecules and host molecules, which has attracted attention as a new type of crosslinking structure, was introduced into a polymer with polymethyl methacrylate (PMMA) as the major monomer. Adamantane (Ad), a cage-shaped molecule, was employed as the guest, and β-cyclodextrin (β-CD), a ring-shaped molecule, served as the host, enabling reversible adhesion between guest-functionalized polymers and host-functionalized polymers. In this report, we employed all-atom molecular dynamics simulations to investigate atomic diffusion and interfacial strength at the guest polymer/host polymer interface. We confirmed qualitative agreement with experiments regarding the presence or absence of host and guest molecules at the interface and the extent of interfacial diffusion due to cross-linking formation. Additionally, uniaxial tensile simulations were conducted to investigate the effect of crosslink formation on the mechanical properties of the diffusion interface. The result demonstrated that such cross-linking significantly enhances interfacial toughness.