Synthesis of ionic liquid crystal dendrimers and investigation of their mesomorphic properties

Abstract

Dendrimers are highly branched, multi-functional and monodispersed macromolecules. Due to their unique properties, many application fields utilize them. The field of liquid crystalline, which has become dominant in our modern life for a couple of decades, has started to utilize dendrimers at the level of research interest. In the literature, by changing interior architecture of dendrimer or addition of pro-mesogenic or nonmesogenic units onto the exterior of dendrimer, various studies have been performed. In our study, new sets of dendritic ionic liquids have been synthesized. When synthesizing them, amine terminated PAMAM, PPI, trimesic acid core amidoamine dendrimers have been firstly synthesized or purchased. In addition, various types of promesogenic alkoxy-benzoic acids are attached onto periphery of dendrimer via electrostatic interaction. Longer and shorter alkoxy chains of acids are investigated. Ionic synthesis is checked by FT-IR and NMR spectroscopy. Mesomorphic characterization is performed by POM and DSC studies. The great majority of these salts have gained large mesomorphic range. To see the difference between ionic and covalent attachment onto the periphery of dendrimer, PPI based new macromolecules have been synthesized. These molecules are characterized by FT-IR, NMR, POM and DSC.