Rational Designed Polymeric Rigid Cages for Trapping Bulky Vegetable Oils toward Versatile Bio‐Based Adhesives

Abstract Polymer gels stand out as emerging and promising materials in adhesives. However, flexible network and network–solvent mismatch affect their strengths and stabilities. Regulating the network architectures of polymer gels via molecular design is a promising strategy to overcome these drawbacks. Herein, a novel polymeric rigid cage (PRC) network structure design is proposed for capturing bulky vegetable oils via mechanically interlocking supramolecular interactions or steric hindrance effect to fabricate universal polymer gels‐based adhesives. By rationally designing and refining the architectures, the rigid cage prepared by 4,4′‐diphenylmethane diisocyanate (MDI) and N , N , N ″, N ″‐tetra(2‐hydroxypropyl) ethylenediamine (EDTP) possesses optimal encapsulation effect for epoxidized linseed oil (ELO). The resulting RCE‐50 gel exhibited robust mechanical properties (≈65 MPa) and excellent stability (high temperatures, high pressures, solvents immersion). Owing to high strength and stability of the polyurethane network, adhesion effect of high‐density amino ester groups, as well as the hydrophobic and toughening effects of ELO, the RCE‐50 gel can be used as a versatile adhesive with high adhesive strength under different conditions. This study proposes a new approach for innovating the properties of polymer gels, provides a novel idea for designing porous polymer materials, and offers fresh insights for developing versatile bio‐based adhesives.