In recent years, a novel crosslinking approach based on cyclic macromolecular monomers, known as "mobile crosslinking," has attracted significant attention as an alternative to traditional chemical and physical crosslinking methods. This method enhances flexibility and impact resistance through dynamic structural adjustments but may also lead to reduced stiffness and strength. Therefore, achieving a balance between toughness and strength has become a critical challenge in this field. To address this issue, researchers have explored polymer composites reinforced with cellulose nanocrystals (CNC).
In this study, we focused on polymer matrix composites with mobile crosslinking, using cyclodextrin (CD) as the cyclic macromolecular monomer and CNC as the reinforcing agent. Through multiscale simulations, we systematically investigated the mechanical mechanisms of these composites. Specifically, we employed multiscale finite element analysis to quantify the reinforcing effects of CNC fibers based on strain energy and proposed a design strategy to optimize the mechanical performance of the composite. Furthermore, to elucidate the molecular mechanism of mobile crosslinking, full-atom molecular dynamics simulations were conducted to analyze the role of cyclodextrin in the composite. We examined how cyclodextrin influences the structural changes and interactions of the polymer backbone. The simulation results demonstrated that the introduction of cyclodextrin significantly enhances material performance, with the maximum tensile strength increased by 487%.