Search

The reconfigurable and reprocessable thermadapt two‐way shape memory polymers (2W‐SMPs) are highly desirable for many advanced biomimetic applications, but the preparation of these polymers with economical raw materials and convenient approaches still remains a challenge. In this work, thermadapt 2W‐SMPs based on a dual crosslinking network are synthesized by linking polyethylene glycol with hydroxylated modified SBS via dynamic covalent bonds. Benefiting from the synergistic effect of combining a dynamic covalent network and a physical cross‐linking network, the thermadapt 2W‐SMPs exhibit a good balance of mechanical properties and favorable two‐way shape memory effect (2W‐SME) with the reversible actuation strain of 11.9%. The 2W‐SMPs can be reprocessed and transformed into complex 3D shapes after multiple folding processes due to the dynamic covalent exchange as well as the reversible physical crosslinking, and the obtained new samples still exhibit good 2W‐SMEs. Furthermore, the transition temperature of 2W‐SMPs is designed to be close to human body temperature, and it is manufactured into a biomimetic mimosa actuator that can undergo shape changes through finger contact and cooling. This work provides a new idea for the development of thermadapt 2W‐SMPs, and the obtained materials show great potential applications in intelligent actuators. [ABSTRACT FROM AUTHOR]

Shape‐morphing materials that can exhibit various shape deformations are highly desirable. In this work, shape‐morphing materials with diverse deformation modes are prepared via a facile approach of constructing bilayer structures of SEBS/paraffin blends with different melting temperatures. The bilayer films are prepared using a simple solvent‐coating adhesion method, either by adhering two single‐layers together and stretching or by adhering two pre‐stretched single‐layers. These bilayer films show strong interfacial adhesion due to the similar chemical composition of the two layers. By adjusting the programming method, stretching strain, and thickness ratio, the shape deformation behaviors of the resultant bilayer films can be flexibly tuned. To demonstrate the wide applicability of this approach, several 2D sheets with hinge structures as well as a smart dressing are prepared, in which the former can be transformed into 3D configurations and the latter can automatically fit to the human body and peel off. Owing to the advantages of low cost, easy and large‐scale preparation, recyclability, and high designability, the approach for preparing shape‐morphing bilayer films proposed by this work is versatile and the obtained bilayer films have the potential to satisfy the demands of divergent application fields. [ABSTRACT FROM AUTHOR]