Article
  • Thermal Stability of Polarized UV Exposed Polyimide Films for Liquid Crystal Display
  • Kim IH, Kim WS, Ha K
  • 편광 자외선이 조사된 액정 디스플레이용 폴리이미드 필름의 열 안정성
  • 김일형, 김욱수, 하기룡
Abstract
We studied the orientation behavior and thermal stability of polyimide (PI) molecules under irradiation of polarized UV (PUV) using polarized fourier transform infrared (FTIR) spectroscopy. In the case of PUV-exposed PI films, the remaining PI molecules after photo-degradation showed molecular orientation perpendicular to the irradiated PUV polarization direction predominantly, due to the preferential degradation of PI molecules parallel to the irradiated PUV polarization direction. On the other hand, the rubbing of PI films induced reorientation of the PI molecules parallel to the rubbing direction. We also investigated the thermal stability of the alignment layers formed by rubbing and PUV irradiation on the PI films using polarized FTIR. The thermal stability of the PUV irradiated PI alignment layer is lower than that of the rubbed PI layer due to the fragmentation reaction of the PI by PUV.

편광 푸리에 변환 적외선 분광법을 이용하여 액정 디스플레이의 배향막으로 널리 사용되는 폴리이미드 필름의 편광 자외선 조사에 따른 액정의 배향성과 열적 안정성을 연구하였다. 편광자외선이 조사된 폴리이미드의 경우, 조사된 편광자외선의 극성 방향에 평행한 폴리이미드 분자들의 우선적인 광분해 반응으로 인하여 편광자외선 조사 후 남아 있는 폴리이미드 분자들은 조사된 편광자외선 극성 방향과 수직 배향을 나타내었다. 하지만 러빙 처리된 폴리이미드 필름은 러빙 방향과 평행하게 폴리이미드 분자들의 재배향이 유도됨을 확인하였다. 또한 편광자외선이 조사된 폴리이미드 배향막이 편광자외선 조사를 통한 폴리이미드 분자들의 단편화 반응 때문에 러빙 처리된 폴리이미드 배향막 보다는 열적 안정성이 저하됨을 확인하였다.

Keywords: polyimide; polarized UV; liquid crystal; FTIR; orientation; thermal stability

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  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2023 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 2002; 26(4): 431-438

    Published online Jul 25, 2002

  • Received on Feb 6, 2002
  • Accepted on May 10, 2002