Mesomorphic and dielectric properties of a side-chain liquid crystalline polyacrylate and copper(II) crosslinked derivatives

A side-chain liquid crystalline polyacrylate containing a salicylaldimine g roup has been synthesized and complexed with copper(II) ions to generate me tallomesogenic crosslinking of polymeric chains. The mesomorphic properties of the parent and complexed polymers have been studied by optical microsco py, DSC and X-ray diffraction. In addition, these materials have been inves tigated in depth by dielectric spectroscopy. Dielectric measurements of the parent polymer reveal the presence of two sub-glass relaxations (beta and gamma). The alpha relaxation associated with the T-g is masked by a conduct ive process, but at higher temperatures a delta relaxation is observed. The se relaxation processes have been characterized and their activation energi es evaluated. The influence of the mesogenic order and metal crosslinking o n some relaxation processes has also been determined.