광반응성 작용기를 주사슬에 갖는 폴리아미드의 합성과 특성 분석 및 액정분자의 배향 특성

정은영; 이태진; 이승우; Eun Young Jung; Tae Jin Lee; Seung Woo Lee

Polymer(Korea), Vol.35, No.4, 350-355, July, 2011

Synthesis and Characterization of Polyamide Having Photoreactive Group in the Backbone and its Liquid Crystal Aligning Property

정은영, 이태진 , 이승우^†

영남대학교 디스플레이화학공학부

Eun Young Jung, Tae Jin Lee , and Seung Woo Lee^†

School of Display & Chemical Engineering, Yeungnam University, 214-1 Dae-dong, Gyeongsan 712-749, Korea

E-mail:

초록

고분자의 주사슬에 광반응을 할 수 있는 phenyldiacryloyl 그룹을 가지고, 곁사슬에 액정분자와 비슷한 메조겐인 biphenyl을 에테르 결합을 통해서 도입된 가용성 광반응성 폴리아미드를 합성하였다. 합성된 폴리아미드 고분자는 0.65 dL/g의 대수점도를 가지며, 일반적인 코팅 방법으로 여러 기질의 표면에 잘 도포되는 성질을 보였다. 광반응성 폴리아미드 고분자의 화학 구조는 1H NMR과 Fourier transform infrared(FTIR) spectroscopy를 이용해서 확인하였다. 합성된 고분자의 유리전이온도는 150 ℃까지 관측되지 않았으며, 열분해 온도는 280 ℃로 관측되어, 열안정성이 높음을 확인하였다. 합성된 폴리아미드 고분자 박막을 비편광된 자외선을 노광시켜 노광하는 에너지에 따른 변화를 조사했을 때, 좋은 광반응성을 보였다. 광반응성 폴리아미드를 이용하여 선편광된 자외선을 노광하여 제작한 액정 셀 내에서, 액정분자들은 노광된 선편광 자외선의 electric vector 방향의 수직으로 배향되는 것이 관측되었으며, 이러한 현상은 선편광 자외선의 노광량에는 무관함을 보였다. 액정 셀 내에서 액정분자들의 pretilt angle은 선편광된 자외선의 노광량에 따라 약간의 차이를 보이며 0.2°에서 0.5° 사이의 값을 보였다.

A soluble polyamide containing photosensitive 1,4-phenylenediacrylic acid (PDA) in main chain with biphenyl moiety was synthesized. The chemical structure of synthesized polyamide was investigated by means of 1H NMR spectroscopy. The polymer was stable up to 280 ℃ and soluble in organic solvents, giving a good quality of thin films. The photoreaction of unpolarized UV irradiated films was investigated by means of UV-vis absorption spectroscopy and FTIR spectroscopy, and liquid crystals (LCs) alignment property was examined by exposing to linearly polarized UV light (LPUVL) of 260∼380 nm. The polyamide in film has excellent photoreactivity to unpolarized UV light. Direction selective photoreaction of PDA moiety in the film was found to further induce nematic liquid-crystals to align along a perpendicular direction with respect to the electric vector of LPUVL, regardless of exposure energy of LPUVL. In addition, pretilt angle was measured by means of crystal rotation method. LPUVL-exposed polymer film induced the alignment of liquid-crystals (LC) with a pretilt angle of 0.2∼0.5°.

Keywords:photo-reactive polyamide;liquid crystals;alignment layer;photo reactivity;pretilt angle.

[References]

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Schadt M, Seiberle H, Schuster A, Nature, 381(6579), 212 (1996)
Castellano JA, Liquid Crystal Display: Handbook of Display Technology, Academic, San Diego, CA, Chap.8, 181 (1992)
O'Mara WC, Liquid Crystal Flat Panel Display, van Nostrand & Reinhold, New York (1992)
Seo DS, Kobayashi S, Nishikawa M, Appl. Phys. Lett., 62, 2392 (1992)
Ban BS, Kim YB, J. Am. Chem. Soc., 103, 3869 (1999)
Lee ES, Vetter P, Miyahita T, Uchida T, Jpn. J. Appl. Phys., 32, L1339 (1993)
Samant MG, Stohr J, Brown HR, Russell TP, Sands JM, Kumar SK, Macromolecules, 29(26), 8334 (1996)
Lee SW, Lee SJ, Hahm SG, Lee TJ, Lee B, Chae B, Kim SB, Jung JC, Zin WC, Sohn BH, Ree M, Macromolecules, 38(10), 4331 (2005)
Chae B, Lee SW, Lee B, Choi W, Kim SB, Jung YM, Jung JC, Lee KH, Ree M, J. Phys. Chem. B, 107(43), 11911 (2003)
Ban BS, Rim YN, Kim YB, Liq. Cryst., 27, 125 (2000)
Gibbons WM, Shannon PJ, Sun ST, Swetlin BJ, Nature., 351, 49 (1991)
Ichimura K, Chem. Rev., 100(5), 1847 (2000)
O`Neill M, Kelly SM, J. Phys. D: Appl. Phys., 33, R67 (2000)
Obi M, Morino S, Ichimura K, Chem. Mater., 11, 656 (1996)
Jackson PO, Oneill M, Duffy WL, Hindmarsh P, Kelly SM, Owen G, Chem. Mater., 13, 694 (2001)
Chae B, Lee SW, Ree M, Jung YM, Kim SB, Langmuir, 19(3), 687 (2003)
Lee SW, Kim SI, Lee B, Kim HC, Chang TY, Ree M, Langmuir, 19(24), 10381 (2003)
Lee SW, Ree M, J. Polym. Sci. A: Polym. Chem., 42(6), 1322 (2004)
Lee SW, Chang TY, Ree M, Macromol. Rapid Commun., 22(12), 941 (2001)
Lee SW, Kim SI, Lee B, Choi WY, Chae B, Kim SB, Ree M, Macromolecules, 36(17), 6527 (2003)
Hasegawa M, Jpn. J. Appl. Phys., 38, L457 (1999)
Ichimura K, Akita Y, Akiyama H, Kudo K, Hayashi Y, Macromolecules, 30(4), 903 (1997)

[Related Articles]

[1] Schadt M, Schmitt K, Kozinkov V, Chigrinov V, Jpn.J. Appl. Phys., 31, 2115 (1992)

[2] Schadt M, Seiberle H, Schuster A, Nature, 381(6579), 212 (1996)

[3] Castellano JA, Liquid Crystal Display: Handbook of Display Technology, Academic, San Diego, CA, Chap.8, 181 (1992)

[4] O'Mara WC, Liquid Crystal Flat Panel Display, van Nostrand & Reinhold, New York (1992)

[5] Seo DS, Kobayashi S, Nishikawa M, Appl. Phys. Lett., 62, 2392 (1992)

[6] Ban BS, Kim YB, J. Am. Chem. Soc., 103, 3869 (1999)

[7] Lee ES, Vetter P, Miyahita T, Uchida T, Jpn. J. Appl. Phys., 32, L1339 (1993)

[8] Samant MG, Stohr J, Brown HR, Russell TP, Sands JM, Kumar SK, Macromolecules, 29(26), 8334 (1996)

[9] Lee SW, Lee SJ, Hahm SG, Lee TJ, Lee B, Chae B, Kim SB, Jung JC, Zin WC, Sohn BH, Ree M, Macromolecules, 38(10), 4331 (2005)

[10] Chae B, Lee SW, Lee B, Choi W, Kim SB, Jung YM, Jung JC, Lee KH, Ree M, J. Phys. Chem. B, 107(43), 11911 (2003)

[11] Ban BS, Rim YN, Kim YB, Liq. Cryst., 27, 125 (2000)

[12] Gibbons WM, Shannon PJ, Sun ST, Swetlin BJ, Nature., 351, 49 (1991)

[13] Ichimura K, Chem. Rev., 100(5), 1847 (2000)

[14] O`Neill M, Kelly SM, J. Phys. D: Appl. Phys., 33, R67 (2000)

[15] Obi M, Morino S, Ichimura K, Chem. Mater., 11, 656 (1996)

[16] Jackson PO, Oneill M, Duffy WL, Hindmarsh P, Kelly SM, Owen G, Chem. Mater., 13, 694 (2001)

[17] Chae B, Lee SW, Ree M, Jung YM, Kim SB, Langmuir, 19(3), 687 (2003)

[18] Lee SW, Kim SI, Lee B, Kim HC, Chang TY, Ree M, Langmuir, 19(24), 10381 (2003)

[19] Lee SW, Ree M, J. Polym. Sci. A: Polym. Chem., 42(6), 1322 (2004)

[20] Lee SW, Chang TY, Ree M, Macromol. Rapid Commun., 22(12), 941 (2001)

[21] Lee SW, Kim SI, Lee B, Choi WY, Chae B, Kim SB, Ree M, Macromolecules, 36(17), 6527 (2003)

[22] Hasegawa M, Jpn. J. Appl. Phys., 38, L457 (1999)

[23] Ichimura K, Akita Y, Akiyama H, Kudo K, Hayashi Y, Macromolecules, 30(4), 903 (1997)