Enhanced Thermomechanical Response in Supramolecular Liquid Crystalline Elastomers With End‐On Mesogens | CU Experts

ABSTRACTLiquid crystalline elastomers (LCEs) exhibit reversible macroscopic shape changes in response to a temperature change. Mechanistically, the thermomechanical response of LCEs is associated with the thermotropic nature of the liquid crystalline units (i.e., mesogens) in the polymer network. Upon heating, the mesogen‐mesogen interaction in the LCE is disrupted, which transitions the organization of the polymer network from an ordered to a disordered state. The disruption in order affects the volumetric distribution of macromolecular chains in the polymer network and results in a large directional contraction along the alignment axis. Prior reports detail that the magnitude of actuation depends strongly on the connectivity of LC mesogens (i.e., main‐chain or pendant) within the network. In this study, pendant end‐on mesogens are introduced into a primarily main‐chain supramolecular LCE composition to further reduce crosslink density while preserving overall LC concentration. The introduction of pendant end‐on mesogens to supramolecular LCE compositions further improves thermomechanical properties by enhancing strain‐temperature coupling and reducing actuation temperatures. By systematically varying the concentrations of end‐on and supramolecular mesogens, direct relationships are established between mesogen composition, polymer architecture, and the resulting thermomechanical performance of LCEs.

VIVO