Yeni kalgon bazlı sıvı kristal polimerlerin sentezi ve incelenmesi

Side chain liquid crystalline polymers (SCLCPs), which combine the unique properties of low-molar mass liquid crystals and polymers, have been the subject of intensive research mainly due to their interesting electrical and optical properties which makes them good candidates for applications in microelectronic devices ranging from optical data storage and nonlinear optics. Side chain liquid-crystalline polymers (LCPs) are usually prepared by covalently linking rigid mesogens to a polymer backbone through flexible spacers. In thesis, new chalcone compound and its methacrylate monomer were synthesized aand characterized. 1-(4-hydroxyphenyl)-3-(pyridin-4-yl)prop-2-en-1-one as a chalcone compound was synthesized by using Claisen-Schmidt method. 1-(4-hydroxyphenyl)-3-(pyridin-4-yl)prop-2-en-1-one was reacted with methacryloyl chloride to obtain monomer. This chalcone based monomer was polymerized by using free radical polymerization method. Chalcone side chain liquid crystalline polymer was prepared by using intermolecular hydrogen bonding concept. For this purpose, firstly H-bonded crystalline polymer was synthesized starting from tertiary amine containing methacrylate based polymers as H-bond acceptor and 4'-(-hydroxyalkoxy)-4-cyanobiphenyl derivatives as H-bond donor. Synthesis of Hydrogen Bond Donors: 8-(4-Cyanobiphenyl-4'-oxy) octan-1-ol (LC8) and 11-(4-Cyanobiphenyl-4'-oxy) undecan-1-ol (LC11) were synthesized. The structure of the LC8 and LC11 were characterized by FT-IR and 1H-NMR spectroscopy. Preparation of chalcone based liquid crystalline polymers Chalcone based polymer and LC8 or LC11 were employed as a hydrogen bond acceptor and a hydrogen bond donors, respectively to yield hydrogen bonded liquid crystalline polymers. The structure of the side chain liquid crystalline polymers formed by intermolecular H-bonding between nitrogen of amine of the polymer and hydroxyl group of the hydrogen donors. The hydrogen bonded methacrylate based polymers were characterized by FT-IR spectroscopy, DSC and POM methods. According to the FT-IR spectra of the polymers hydrogen bonding donors and acceptors located so that intramolecular hydrogen bonding is favored, display slightly broadened O-H stretching absorption in the 3200 to 3500 cm-1 range. The phase behavior of all the hydrogen bonded liquid crystalline polymer was studied using a combination of DSC and POM. DSC thermograms were obtained in second heating cycles. The samples were heated with a scan rate of 10°C/min in an N2 atmosphere. POM (X200) studies also confirmed DSC results along with the results of phase transitions. Also, 1-(4-hydroxyphenyl)-3-(pyridin-4-yl)prop-2-en-1-one was interacted with LC8 and LC11 to compare with liquid crystaline polymers.