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

Two methods have been used to end-cap linear polymer chains at one end or a t both ends by a mesogen through ionic bonding. These polymers are designat ed as liquid-crystalline halato(semi)telechelic polymers (LC H(S)TPs). The first method relies on the ion exchange reaction between the metal counteri on of halato(semi)telechelic polymers and an ionic mesogen. The second meth od is based on the proton transfer from a sulfonic or carboxylic acid end-g roup to a tertiary aliphatic amine, this approach being controlled by the r elative pK(a) values of the acidic and basic groups. If the pK(a) differenc e is not large enough, strong hydrogen-bonding is observed by Fourier-trans form infrared (FTIR) spectroscopy rather than proton transfer. The resultin g materials have been characterized by differential scanning calorimetry (D SC), polarized optical microscopy (POM) and small-angle X-ray scattering (S AXS). (C) 2000 Society of Chemical Industry.