Synthesis and Properties of Reactive Liquid Crystal Monomers

Abstract

A new series of nematic liquid crystal (LC) monomers containing double bonds in the side chain were designed and synthesized via the Steglich esterification reaction. Length of the side groups varied from 1 to 2 methylene units. The molecular structures of the intermediates and the LC monomers were confirmed by Fourier transform infrared spectrum, elemental analysis, and nuclear magnetic resonance spectroscopy. The thermal phase behavior of the LC monomers was investigated by differential scanning calorimetry and polar optical microscopy coupled with hot stage. All of these LC monomers showed only one nematic mesophase at room temperature during the cooling process.

Keywords:

• Liquid crystal
• nematic
• reactive liquid crystal
• synthesis

Acknowledgments

This work is financially supported by the Basic Research Foundation of Northwestern Polytechnical University (JC201047). We would like to thank Dr. Baojian Liu for his assistance in obtaining some of the NMR spectra and Prof. Xiaodong Fan for the analysis of DSC and FT-IR.