Abstract:
A main-chain poly(disulfide)-based liquid crystalline elastomer (PDS-LCE) was successfully constructed via ring-opening polymerization of dual lipoate thioester-terminated liquid crystalline oligomers (LT-LCO) with dual-thiol-terminated liquid crystalline oligomers (SH-LCO) under the white-light irradiation. The distinctive white-light response enables spatially resolved programming of the resulting PDS-LCE. Optimal fabrication conditions were identified as an initial polymerization time of 4 h, a pre-stretching strain of 200%, and an SH-LCO molar ratio of 20%, yielding an aligned film with an actuation strain of 35.2% and a work capacity of 340 kJ/m
3. By employing photomasks during irradiation, localized alignment can be selectively locked, generating internal stress fields that drive out-of-plane deformations. For example, a rectangular film programmed with an H-shaped mask adopts a twisted configuration at room temperature. Owing to stress relaxation during the stretching process, the programmed regions retain a longer equilibrium length than the unprogrammed regions. Upon heating, this length mismatch creates internal stresses that reshape the film into a saddle-like morphology, allowing room-temperature and elevated-temperature shapes to be programmed simultaneously. A regular octagonal film subjected to sequential masking and stretching steps spontaneously forms a double-arch morphology at room temperature, which reversibly switches to a saddle-shaped polyhedron upon heating. Furthermore, dynamic disulfide exchange under thermal stimulation imparts macroscopic reconfigurability. Thermal erasure resets the material to its isotropic state, enabling subsequent thermal reprogramming into new geometries such as a folded triangle or a rolled cylinder. The dynamic disulfide network also provides excellent self-healing capability, achieving 94.3% recovery of mechanical properties after thermal healing, as well as complete chemical recyclability via reductive depolymerization with a recovery yield of 92.4%.