Assessing the Sequence Specificity in Thermal and Polarized Optical Order of Multiple Sequence-Determined Liquid Crystal Polymers

To assess the inherent effect of sequence distribution on thermal and polarized optical order, side chain liquid crystal polymers (SCLCPs) with precise side-chain sequence control were synthesized and characterized. Multiple uniform (M-U), alternating (M-A), gradient (M-G), and interval (M-I) polymers were conveniently used as well designed Si H functional backbones, and the treatment of these sequence-determined backbones with mesogenic moieties was conducted via highly efficient hydrosilylation to obtain sequence-determined SCLCPs with well-designed molecular compositions and narrow polydispersity index (PDI). The molecular arrangement of multiple analogous architectures was constructed, which provided the unique opportunity to comprehensively study how the sequence impacts liquid crystalline (LC) behavior. The general trends that the thermal and polarized optical order are significantly sensitive to sequence specificity in the order M-U > M-A > M-G > M-I for a given SCLCPs with a similar number or similar overall concentration of mesogenic moieties are deduced. Here, SCLCPs with important sequence control led to increased understanding of interior structure property relations owing to the specific spacing between adjacent LC pendants. As such, this spacing will be recognized as an essential parameter that determines LC properties that are of interest to be explored.