화학공학소재연구정보센터
Polymer(Korea), Vol.21, No.1, 26-35, January, 1997
가교된 Epoxy Resin 분산 액정의 제조 및 상분리 거동
Synthesis of Crosslinked Liquid Crystalline Epoxy Polymer and LMWLC Phase Separation Behavior
초록
말단에 NH2기를 가지는 저분자 액정 4-[4-(n-aminoalkyloxy) phenylazo]benzonitrile AAB (n=6, 8)을 합성하였으며 DSC 및 편광 현미경 관찰을 통해 nematic texture를 확인하였다. AAB(6)과 ethyleneglycol diglycidyl ether (EGDE)를 반응시켜 선형 epoxy계 측쇄 액정 고분자(ELCP)를 얻었으며 액정 전이온도(Tiso)는 저분자 액정, AAB(6)보다 낮게 나타났다. AAB(n=6, 8)과 EGDE 및 가교제로서 1,10-diaminodecane (DA) 및 triglycidyl isocyanurate (TGI)를 이용하여 각각 가교된 epoxy계 액정 중합체 XDLCP 및 XTLCP를 얻었으나 가교 효율은 낮게 나타났다. XTLCP의 경우 TGI 함량이 30mo1% 이상에서 액정성을 나타내지 않았다. 상용품 저분자 액정 (E7)을 EGDE/DA 단량체와 혼합하여 polymerization induced phase separation 법으로 가교 고분자 분산액정을 제조하였으며 E7의 무게 비율이 35wt% 이상에서 저분자 액정의 상분리가 관찰되었다. 분산상의 전이온도는 저분자 액정 E7의 TNI=60.5와 유사하게 나타났다.
Liquid crystals with terminal NH2 functional group, 4-[4-(n-aminoalkyloxy)phenylazo]benzonitrile, AAB(n=6, 8) were synthesized and nematic textures were observed by the polarized optical microscope. AAB(6) was reacted with ethyleneglycol diglycidyl ether (EGDE) to give linear epoxy type liquid crystalline polymers (ELCPs). The liquid crystal-isotropic transition temperature (Tiso) of ELCPs was lower than that of low molecular weight liquid crystal, AAB(6). Crosslinked epoxy type liquid crystalline polymers, XDLCPS and XTLCPS were synthesized by using 1,10-diaminodecane (DA) and triglycidyl isocyanurate (TGI) crosslinker, respectively in addition to EGDE and AAB (n=6, 8). The efficiency of crosslinking reaction was not high either DA or TGI as crosslinker. A commercial liquid crystal (E7) sample from BDH company was mixed with EGDE/DA as crosslinking monomers and pc)Yrnerlzatlon Induced f)tlase separation was conducted to give crosslinked polymer dispersed liquid crystal (PDLC) samples. The crosslinked type PDLC samples showed no phase separation up to 30wt% of E7 in the PDLC mixture of which Tiso was very close to that of E7 (60.5℃) itself. It was also noted that the size of dispersed liquid crystal (E7) phase was dependent on the temperature and weight percent of E7 in the E7/EGDE/DA mixture.
  1. Gunjima T, Polymer, 43, 293 (1994)
  2. Karin MA, "Electro-Optic Displays," Marcel Dekker, N.Y. (1992)
  3. Bredas JL, Salaneck WR, Wegner G, "Organic Mataerials for Electronics," North-Holland (1994)
  4. Lee KC, Kang YC, "Fundamental Principle and Application of Liquid Crystal Electronics," Kijeon Pub. (1992)
  5. Kamada T, Japan Diaplay '92, Hiroshima, PD-12 (1992)
  6. Kitzerow HS, Liq. Cryst., 16, 1 (1994)
  7. Crooker PP, Yang DK, Appl. Phys. Lett., 57, 2529 (1990) 
  8. Chien LC, Lin C, Fredly DS, McCarar JW, Macromolecules, 25, 133 (1992) 
  9. West JL, Mol. Cryst. Liq. Cryst., 157, 427 (1988)
  10. Cada LG, Chien LC, Macromol. Chem. Phys., 195, 1733 (1994) 
  11. Smith GW, Mol. Cryst. Liq. Cryst., 180B, 201 (1990)