• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.553-555
• /
• 2007

Six azomethine polymers containing bent-core mesogen were synthesized with variation of a bent structure of central core (1,2-dioxyphenylene or 2,3-dioxynaphthylene), and a lateral halogen substituent (X = H, F or Cl ). The properties of the polymers were characterized by FT-IR, NMR spectroscopy, DSC, polarizing optical microscopy, and X-ray diffractometry.

• 공업화학
• /
• 제26권3호
• /
• pp.280-286
• /
• 2015

유연격자로서 분자 중앙에 부틸렌 또는 펜타메틸렌기를 갖는 두 시리즈의 비대칭 이메소젠 화합물을 합성하고, 이들의 열적성질 및 액정성을 연구하였다. 합성된 화합물의 메소젠기는 콜레스테릴기와 곁 치환기를 포함하고 있는 아조벤젠기로 되어 있으며, 이들 액정화합물의 화학구조와 액정성은 FT-IR, $^1H$-NMR, 시차주사열량분석기(DSC), 편광현미경(POM)에 의하여 조사되었다. 화합물 $D5-OCH_3$를 제외한, 합성된 모든 화합물들은 양방성 액정성을 나타내었고, 유연격자의 탄소수가 짝수인 경우 넓은 액정상 온도구간과 높은 등방성 전이온도를 나타내었다. 곁 치환기가 액정성에 미치는 영향으로, 부피가 큰 치환기를 갖는 화합물들은 좁은 액정상 온도구간과 낮은 등방성 전이온도를 나타내었으며, 극성 치환기를 갖는 화합물들은 스멕틱 액정상의 높은 안정성을 나타내었다.

• 한국고분자학회:학술대회논문집
• /
• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
• /
• pp.242-243
• /
• 2006

In this work, we report the synthesis and characterization of azomethineester polymers that consist of banana-shaped mesogen in their backbone. Two parts of the key structure of five-ring bent-core mesogen were modified by connecting different angle of central unit (Ar), and introducing lateral substituent into the outer ring (X). The synthetic details includes (1) placing the dioxydodecamethylene unit as a flexible spacer, (2) possessing 2,3- or 2,7-naphthylene, or 1,2-phenylene connection on the central unit, and (3) introducing fluorine or chlorine substituent (X = F or Cl) into the outer phenylene unit.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.171-174
• /
• 2006

In this work, we report the synthesis and characterization of azomethine-ester polymers that consist of banana-shaped mesogen in their backbone. Two parts of the key structure of five-ring bent-core mesogen were modified by connecting different angle of central unit (Ar), and introducing lateral substituent into the outer ring (X). The synthetic details includes (1) placing the dioxydodecamethylene unit as a flexible spacer, (2) possessing 2,3- or 2,7-naphthylene, or 1,2-phenylene connection on the central unit, and (3) introducing fluorine or chlorine substituent (X = F or Cl) into the outer phenylene unit.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1998년도 가을 학술발표회논문집
• /
• pp.94-97
• /
• 1998

We have been studying :he synthesis of thermotropic polyurethanes, based on structural modifications by means of (i) the introduction of bulky substituent group in the aromatic ring to decrease the degree of lateral packing, (ii) the copolymerization of two kinds of monomers having different alkylene lengths to lower the regularity of the polymer structure, and (iii) the use of nonlinear monomers to lower the persistence length of the polymer chain in the liquid crystalline phase and to decrease the lateral interactions in the solid state. (omitted)

• Bulletin of the Korean Chemical Society
• /
• 제25권8호
• /
• pp.1171-1176
• /
• 2004

Three banana-shaped achiral compounds, 4-chloro-1,3-phenylene bis [4-{4-(undecenyloxy)phenyl imino-methyl} benzoate] derivatives, were synthesized with variation of a substituent (x=H, F, Cl); their antiferro-electric properties are described. The smectic mesophases, including a switchable chiral smectic C(Sm $C^{\ast}$) phase, were characterized by differential scanning calorimetry, polarizing optical microscopy, triangular wave method, and X-ray diffractometry. The presence of vinyl groups at the terminals of linear side wings in the banana-shaped achiral molecules induced a decrease in melting temperature and formation of the switchable Sm $C^{\ast}$ phase in the melt. The smectic phase having a lateral fluorine-substituent at 3-position of the Schiff's base moiety showed antiferroelctric switching, and the value of spontaneous polarization on reversal of an applied electric field was 250 nC/$cm^2$ .

• 대한화학회지
• /
• 제44권2호
• /
• pp.127-137
• /
• 2000

비스(파라-치환페닐)테레프탈산 에스테르의 중앙 테레프탈산 벤젠고리 측면에 데실옥시기가 결합하고 있는 열한개의 새로운 화합물을 합성하였고, 이들의 열적 및 액정 성질을 DSC와 가열판이 부착된 편광현미경을 사용하여 조사하였다. 메소겐의 말단 치환기 X= -H(II-H), -F(II-F), -Cl(Il-Cl), -Br(Il-Br), -I(II-I), -$NO_2(lI-NO_2$), $-CF_3(II-CF_3$), -$OC_2H_5(II-OC_2H_5$), -$OC_4H_9(II-OC_4H_9$), -CN(II-CN) 및 -$C_6H_5(Il-C_6H_5$)로 바꾸었다. $II-OC_2H_5,\;II-OC_4H_9$, 및 $II-C_6H_5$는 단방성 네마틱 액정이었으며, II-H, lI-F, II-Cl, Il-Br, II-I, $II-NO_2$, $II-CF_3$, 및 Il-CN은 액정이 아니었다.