Photo-Alignment Using Benzophenone Sensitized Photodecomposition of the Polyimide

Abstract

For more aggressive photo-decomposition of polyimide, the photoreactions employing triplet mechanism and the double fragmentation reactions were carried out. The polyimide was synthesized with cyclobutane-1, 2, 3, 4-tetracarboxylic dianhydride (CBDA) and 4, 4′-diaminobenzophenone (DABP) by condensation reaction. The benzophenone is well known triplet photo sensitizer, which was mixed with the equal mole ratio of the CBDA, The imidization reaction was confirmed by imide peak formation in FT-IR spectra. The orientation of polymer chains was confirmed by polar dichroic ratio of the liquid crystal cells. The benzophenone chromospheres shortened the UV irradiation time for the photodecomposition and induced the orientation of the polyimide chains.

Keywords:

• Polyimide
• photo-decomposition
• liquid crystal display
• photo alignment

Acknowledgment

This work was supported by the Technology Innovation Program (201210940002, Materials Development for 50-inches UD OLED TV Using Super Hybrid Process) funded by the Ministry of Knowledge Economy (MKE, Korea).