Synthesis and characterization of monodisperse liquid crystalline oligomers: Mapping the evolution of phase behavior from monomer to polymer

The thermo-induced actuation and soft elastic behavior of liquid crystal (LC) polymers have led to their interest for a wide variety of applications, from soft robotics to elastocaloric devices. However, our current understanding of LC polymeric phase transitions is incomplete due to a number of competing variables, including molecular weight dispersity. Notably, the behavior of an LC polymer differs markedly from that of its constituent monomer; the effects of transitioning from monomer to polymer remains relatively unexplored. Here, we apply a new LC synthetic strategy to prepare a series of monodisperse LC oligomers of controlled lengths. We map the effects of increasing molecular weight on the thermal transitions of these LC materials. These results are contrasted with the behavior of comparable species prepared via conventional step-growth polymerization. These studies highlight important factors affecting LC transitions, allowing for the design of more tailored and precise LC behaviors.