Study on Novel Liquid Crystalline Polymer Containing Pyridine Unit in the Main Chain

• Main Authors: Danchin Wang, 王丹青
• Other Authors: Jen-Feng Kuo
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/66317393226452616860

碩士 === 國立成功大學 === 化學工程學系 === 87 === Abstract This study deals with aromatic ester triad with a central 2,5-pyridinedicarbonyl and two terminal oxybenzoyl units connected by a flexible polymethylene spacer containing two, six and ten methylene units, and those POE segments were introduced into their main chain. Using FT-IR to confirm structures, phenol/TCE mixture to find intrinsic viscosities, [], of each polymer being synthesized. The thermal properties of them were studied by differential scanning calorimetry and on a hot-stage of a polarizing microscope. Mesophases were also reexamined by wide angle X-ray scattering, while thermal stabilities were determined by thermogravity analysis. Introducing POE segments into the polymer main chain does not change mesophase textures but increased energies needed for phase-transition. Polymers without POE segments decomposited at 350°C or so, while those with POE segments did depending on the lengths of spacer. All polymers formed nematic phases on melting, but only those with spacers containing more than six methylene units formed smectic states before nematic phases shaped. Wide angle X-ray scattering shows there were layers between repeating units of polymers, which is an evidence of the smectic states.