Preparation of poly (N-vinylcarbazole)-co-poly(2-(dimethylamino)ethyl methacrylate) based hydrogen bonded side-chain liquid crystal copolymer

Abstract

In this study, new side chain liquid crystalline copolymers were prepared from N-vinyl carbazole (NVC) and 2-(Dimethylamino)ethyl methacrylate) (DMAEM) as a hydrogen bond acceptor copolymer and 8-(4-cyanobiphenyl-4'-oxy)octan-1-ol (LC8) by molecular sell assembly processes via hydrogen bond formation between nitrogen of (DMAEM) and hydroxyl group of the LC8. The formation of H bond was confirmed by using FTIR spectroscopy. The liquid crystalline behavior of the copolymers and homopolymer of the (DMAEM) was investigated using a differential scanning calorimeter (DSC) and polarized optical microscopy. The dielectric relaxation properties of H-bonded Side Chain LC Copolymers (HB-LCP) doped 8-(4-cyanobiphenyl-4'-oxy)octan-1-ol (LC8) and pure LC8 liquid crystals have been investigated by the dielectric spectroscopy (DS) method. The dielectric behavior of the LCs shows a dielectric relaxation process. The relaxation frequency of the LCs was changed by the addition of HB-PLC. It is evaluated that the dielectric strength and relaxation properties of LC8 and LC8/HB-PLC LCs can be controlled by 1% HB-PLC dopant. (C) 2014 Elsevier Ltd. All rights reserved.