A Class of Rigid–Flexible Coupling Crystalline Crosslinked Polymers as Vapomechanical Actuators

Fabricating mechanically responsive actuators that can efficiently convert external stimuli into mechanical work is of great significance for real-world applications. Herein, we rationally design a class of rigid-flexible coupling crystalline crosslinked polymers (CCPs) to fabricate vapomechanically responsive actuators. Interfacial condensation reactions of flexible macromers with rigid monomers afford a series of freestanding CCP membranes. Notably, it is the first example where crosslinked polymers show high crystallinity and porosity. Moreover, the CCP membranes exhibit good mechanical properties and interesting vapor-triggered actuation performance, which is reversible and repeatable. We find that the unusual polymer structures, high vapor sorption, and anisotropic membranes contribute to the directional deformation performance of the CCP actuators. The synthesis approach in this work provides new insights into the design and fabrication of smart materials for advanced applications.