Ionic end-capping of (semi)telechelic polymers by mesogens

Two methods have been used to end-cap linear polymer chains at one end or at both ends by a mesogen through ionic bonding. These polymers are designated as liquid-crystalline halato(semi)telechelic polymers (LC H(S)TPs). The first method relies on the ion exchange reaction between the metal counterion of halato(semi)telechelic polymers and an ionic mesogen. The second method is based on the proton transfer from a sulfonic or carboxylic acid end-group to a tertiary aliphatic amine, this approach being controlled by the relative pKa values of the acidic and basic groups. If the pKa difference is not large enough, strong hydrogen-bonding is observed by Fourier-transform infrared (FTIR) spectroscopy rather than proton transfer. The resulting materials have been characterized by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS).