Synthesis and characterization of hydrogen bonded 4-octyloxy benzoic acid/sebacic acid binary liquid crystal complex

Abstract

In this study, the binary liquid crystal complex system was synthesized from mesogenic 4-octyloxy benzoic acid (8BAO) and non-mesogenic sebacic acid (SEA) chemical compounds. The thermal and microstructural properties of the synthesized 8BAO/SEA binary liquid crystal complex system were investigated by differential scanning calorimeter (DSC) and polarized optical microscopy (POM). The formation of the hydrogen bond between the 8BAO and SEA compounds was confirmed by Fourier Transformed Infrared spectroscopy (FTIR) assays. The DSC and POM results showed that the 8BAO/SEA binary complex exhibited liquid crystalline properties due to the hydrogen bonds formed. The 8BAO/SEA binary liquid crystal complex showed four phase transition peak indicating Cr↔SmG↔SmC↔N↔I phase sequence during continuous heating and cooling by DSC. This phase sequence has also been confirmed by POM observations. Furthermore, the effect of the heating rate on the phase transition temperature and enthalpy change values was investigated, and as the heating rate increased, the phase transition temperature and enthalpy values generally increased. Additionally, the thermal stability factor and the phase transition order parameter were calculated and the phase transitions were found to be regular.