• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1997년도 추계총회 및 학술발표회 논문집
• /
• pp.32-35
• /
• 1997

Aggregation states ans electro-optic properties of a binary mixture by mixing a side chain type liquid crystalline polymer(LCP) and a low molecular weight liquid crystal(LMLC) have been studied. Side chain liquid crystalline polysiloxanes were synthesized from allyl bromide, p-hydroxy benzoic acid, p-cyanophenol, p-methoxyphenol and polysiloxanes. Low molecular weight liquid crystals were synthesized from allyl bromide, p-hydroxy benzoic acid and 4-cyano 4'-hydroxy biphenyl. And then, their properties were compared with blended liquid crystals. The thermal properties of the blended liquid crystals were evaluated using differential scanning calorimetry. The phase behavior of blended sample with temperature were also observed polarized microscope with hot stage. Thus, it seemed to us that a study of LC polysiloxanes with LMLC would be useful, especially in view of the fact that, systematic investigations have been carried out on the effects of changes in LCP/LMLC binary system on the properties of this relatively new type of liquid crystal.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.433-435
• /
• 2005

We have studied the realigning behavior of liquid crystal molecules in liquid crystalline polymer/liquid crystal(LCP/LC) system when they are exposed to external stimulation such as bending and pressing. The birefringence of the LCP/LC in a flexible display device was measured as a function of bending or pressing deformation. The microscopic dynamic behavior of main chain, side chain, and the LC were characterized by FTIR and polarization optical microscopy. When the device is deformed in scattering memory state, liquid crystal(LC) director is found to align from randomly oriented domain state(scattering state) to homeotropic state.

• Elastomers and Composites
• /
• 제54권1호
• /
• pp.14-21
• /
• 2019

Main-chain/side-chain liquid crystalline polymers (MCSCLCPs) combined with an azobenzene group and a cholesteryl group were synthesized to impart light and temperature sensitivity to the polymer. The polymers were designed with the azobenzene unit as the mesogenic group of the main-chain and various compositions of the azobenzene and cholesteryl units as the mesogenic group of the side-chain. The chemical structures and physical properties of the synthesized polymers were investigated by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, differential scanning calorimetry, thermogravimetric analysis, polarized optical microscopy, and ultraviolet-visible (UV-Vis) spectroscopy. All the MCSCLCPs were amorphous and exhibited enantiotropic liquid crystal phases; these polymers achieved the nematic phase with increasing content of the azobenzene group and exhibited the cholesteric phase with weak liquid crystallinity as the content of the cholesteryl group was increased. Furthermore, the polymers containing the azobenzene group showed photoisomerization when exposed to UV-Vis light, and the CP-A3C7 and CP-A5C5 polymers exhibited thermochromism in the temperature range of the liquid crystal phase.

• 공업화학
• /
• 제30권2호
• /
• pp.219-225
• /
• 2019

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.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.482-483
• /
• 2003

We have synthesized a new material of polyoxetane based liquid crystalline polymer/liquid crystal (LCP/LC) for flexible memory or dynamic mode device and characterized the electro-optics behavior of this system. The microscopic dynamic behavior of main chain, side chain, and the low molecular weight LC were characterized by X-ray scattering and time resolved FTIR..