4-Hydroxy-4''-methoxyazobenzene was synthesized from phenol and p-anisidine through a diazotization reaction. It was reacted with 2-(2-chloroethoxy)ethanol to obtain a new mesogenic alcohol having an azobenzene group sensitive to the ultraviolet. Two kinds oi new photoresponsive monomers were prepared by the reaction of the mesogenic alcohol with itaconic acid and methacryloyl chloride. The resulting itaconate monomer with two symmetrical mesogens was either homopolymerized or copolymerized with the methacrylate or MMA monomers to synthesize three kinds of new photoresponsive side-chain liquid crystalline polymers with azobenzene group such as itaconate homopolymer, itaconate/methacrylate and itaconate/MMA copolymers. Structures of the monomers and the corresponding polymers were identified by FT-IR and ¹H-NMR spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry(DSC) and thermogravimetric analysis (TGA). From optical polarizing microscopy, all the prepared monomers and polymers were found to show enantiotropic liquid crystallinity with smectic texture.

p-Anisidine과 phenol을 반응시켜 4-hydroxy-4''-methoxyazobenzene을 합성하였다. 이것을 2-(2-chloroethoxy)ethanol과 반응시켜 자외선에 민감한 아조벤젠 그룹을 갖는 새로운 mesogenic alcohol을 합성하였다. Mesogenic alcohol을 itaconic acid 및 methacryloyl chloride와 반응시켜 아조벤젠 그룹을 갖는 두가지의 새로운 광응답성 단량체들을 합성하였다. 두 개의 대칭성 메소겐 그룹을 갖는 새로운 itaconate를 라디칼 개시제 존재 하에서 호모중합시키거나 또는 합성한 methacrylate 단량체나 MMA와 공중합시켜 itaconate 호모중합체, itaconate/methacrylate 공중합체 및 itaconate/MMA 공중합체와 같은 세가지 종류의 새로운 광응답성 측쇄형 액정 고분자를 합성하였다. 합성된 단량체와 중합체들의 구조는 FT-IR 및 ¹H-NMR에 의해 확인하였으며, 그들의 열적 상전이 온도 및 안정성들을 DSC 및 TGA에 의해 조사하였다. 한편 광학편광 현미경에 의해 합성된 새로운 단량체 및 중합체들은 모두 스멕틱 구조를 갖는 열방성 액정성을 보였다.

Keywords: thermotropic liquid crystallinity; new idaconate monomer; itaconate polymers; smectic texture; azobenzene group