Presentation Information
[9a-B12-10]Effects of Spacer Length and Mainchain Structures on Liquid Crystal Phases and Thermal Conductivities in Binary Hetero-Mesogen Copolymers
〇(M1)Wakana Uchiyama1, Yuya ISHIZAKI2, Shusaku NAGANO1 (1.Rikkyo Univ., 2.Shinshu Univ.)
Keywords:
Liquid crystalline polymer,Thermal diffusivity,Specific heat capacity
The effects of main chain structures (methacrylate (MA) and siloxane (MS)) and alkylene spacer lengths (C6-12) on the liquid crystalline (LC) phase and thermal diffusivity were investigated for LC copolymers containing azobenzene and cyanobiphenyl (CB) side-chains. The MA copolymers with a longer alkylene spacer (C9-12) for CB side-chains exhibited the highly ordered smectic (Sm) E phase, whereas the shorter spacer (C6-8) MA adopted the less ordered LC phase. In the case of the MS main chain, the copolymer, even with a short alkylene spacer (C6~9), exhibited the SmE phase. Temperature wave analysis revealed that copolymers exhibiting the SmE phase have a high thermal diffusivity. MS copolymers exhibited a higher specific heat capacity than the MA ones by differential scanning calorimetry, reflecting that the MS main-chain possesses higher flexibility and atomic weight. Consequently, the MS copolymers with the SmE phase and a high specific heat capacity exhibited higher thermal conductivity compared with the MA copolymers.