콜레스테릴기와 아조벤젠기를 갖는 곁사슬 액정고분자의 합성 및 성질 = Syntheses and Properties of Side Chain Liquid Crystalline Polymers with Cholesteryl and Azobenzene Functional Groups

국문 초록 (Abstract)

메소젠기로서 다양한 조성의 아조벤젠기와 콜레스테릴기를 갖는 곁사슬 액정고분자를 직접중축합에 의해 합성하고 고분자들의 특성을 조사하였다. 1,1,2,2-테트라클로로에테인으로 측정된 합성된 고분자들의 고유점성도는 0.32과 0.38 dL/g 사이의 값을 나타냈다. 아조벤젠기만을 포함하고 있는 고분자, SP-A10C0를 제외한 모든 고분자들은 부피가 큰 곁사슬의 메소젠기로 인하여 무정형이거나 매우 낮은 결정성을 나타냈다. 합성된 고분자들은 모두 양방성 액정성을 보였으며, 아조벤젠기만을 갖는 고분자 SP-A10C0는 네마틱상을, 그 외의 모든 고분자들은 콜레스테릭상을 나타냈다. 특히, 고분자의 곁사슬로 콜레스테릴기의 함량이 많아지면 콜레스테릴기의 큰 부피로 인하여 액정성이 감소됨을 알 수 있었다.

다국어 초록 (Multilingual Abstract)

Side-chain liquid crystalline polymers with various compositions of azobenzene and cholesteryl functional groups as the mesogenic moiety were synthesized by direct polycondensation, and their properties were investigated. The inherent viscosity values of synthesized polymers were between 0.32 and 0.38 dL/g in 1,1,2,2-tetrachloroethane. All polymers except the SP-A10C0 polymer containing only the azobenzene group were amorphous or exhibited very low crystallinity due to the presence of bulky mesogenic side chains. All synthesized polymers exhibited enantiotropic liquid crystallinity; the SP-A10C0 polymer having only the azobenzene group exhibited a nematic phase, and all other polymers showed a cholesteric phase. In particular, it was found that when the content of cholesteryl groups in the side chain of the polymer increases, the liquid crystallinity decreases due to the bulkiness of cholesteryl groups.

참고문헌 (Reference)

1 마영대, "폴리[1-{4-(4′-니트로페닐아조)페녹시카보닐알카노일옥시}에틸렌]들의 열방성 액정 거동" 한국고분자학회 32 (32): 489-496, 2008

2 박종률, "측면에 치환기를 포함하고 있는 비대칭 이메소젠 액정화합물의 합성 및 성질" 한국공업화학회 26 (26): 280-286, 2015

3 김형준, "아조벤젠 분자의 사슬 내 위치에 따른 고분자 블렌드 박막의 비등방성 광 변형에 관한 연구" 한국공업화학회 23 (23): 65-70, 2012

4 박종률, "말단에 치환기를 갖는 이-아조메소젠 액정화합물의 합성 및 성질" 한국공업화학회 26 (26): 698-705, 2015

5 정승용, "[4-{4′-(니트로페닐아조)펜옥시카보닐}]알카노화 셀룰로오스들의 열방성 액정 거동" 한국고분자학회 33 (33): 58-66, 2009

6 L. V. D. Werff, "Thermochromic composite fibres containing liquid crystals formed via melt extrusion" 48 : 5005-5011, 2013

7 M. R. Karim, "Synthesis of polymerizable liquid crystalline monomers and their side chain liquid crystalline polymers bearing azo-ester linked benzothiazole mesogen" 293 : 1923-1935, 2015

8 Yeong-Soon Gal, "Synthesis and Characterization of Ionic Polyacetylene Derivative with Azobenzene Moieties" 한국공업화학회 12 (12): 235-240, 2006

9 T. Ganicz, "Side-chain liquid crystal polymers(SCLCP) : Methods and materials. An overview" 2 : 95-128, 2009

10 W. L. F. Armarego, "Purification of Laboratory Chemicals" Elsevier Science 2003

11 F. Higashi, "Preparation of aromatic polyesters by direct polycondensation with thionyl chloride in pyridine" 24 : 91-102, 1986

12 J. Horvàth, "Polymerization in liquid crystal-XVII. Effect of flexible substituents in the mesogenic side-chain on the behaviour of mesogenic polymers" 21 : 251-257, 1985

13 N. Tamaoki, "Photochemical phase transition and molecular realignment of glass-forming liquid crystals containing cholesterol/azobenzene dimesogenic compounds" 15 : 719-726, 2003

14 A. V. Bogdanov, "Photo-orientation of azobenzene-containing liquid-crystalline materials by means of domain structure rearrangement" 117 : 13936-13945, 2013

15 C. J. Barrett, "Photo-mechanical effects in azobenzene-containing soft materials" 3 : 1205-1320, 2007

16 J. Ju, "Novel cholesterol-based cationic lipids as transfecting agents of DNA for efficient gene delivery" 16 : 5666-5681, 2015

17 F. Cser, "Nematic polymers and related structures" 40 : C3-459-C3-470, 1979

18 V. Frosini, "Mesophase formation in polymers with anisometric side–groups in relation to their chemical and stereochemical structure" 66 : 21-36, 1981

19 M. Kléman, "Liquid crystals: The fourth state of matter" A37 : 607-608, 1981

20 H. Finkelmann, "Liquid crystalline polymers with biphenyl moieties as mesogenic group" 179 : 2541-2544, 1978

21 S. Alazaroaie, "Liquid crystalline polymers 14. Synthesis and thermal behaviour of some polyethers containing azo-mesogens" 39 : 1333-1339, 2003

22 Y. Tian, "Liquid crystalline coumarin polymers" 201 : 1640-1652, 2000

23 N. Hosono, "Large-area three-dimensional molecular ordering of a polymer brush by one-step processing" 330 : 808-811, 2010

24 H. Kihara, "In situ photochemical conversion from cinnamoyl-functionalized liquid-crystalline monomers to liquid-crystalline dimers" 34 : 1337-1347, 2007

25 M. R. Meadows, "Electro-optic switching using total internal reflection by a ferroelectric liquid crystal" 54 : 1394-1396, 1989

26 S. W. Cha, "Combined type liquid crystalline poly(oxy-1,4-phenyleneoxyterephthaloyl)s bearing cholesterol pendants attached through polymethylene spacers" 34 : 5342-5348, 2001

27 I. S. Kim, "Charateristics and applications of cholesteric liquid crystals (CLC)"

28 I. Nishiyama, "Achiral non-branched rod-shaped liquid crystals showing anticlinic smectic phase" 13 : 1868-1876, 2003