Polyimide (PI) was synthesized by copolymerization of PMDA
MDA and TBCA in this paper. The films prepared by PI can induce the same vertical alignment before and after rubbing. The effect of content of TBCA on the alignment property was discussed
the relative content of surface side chains was observed by the ATR-FTIR spectra of the PI films surface
and the effect of the microgrooves on the liquid crystal was investigated by atomic force microscope (AFM). The PI films without microgrooves before rubbing can align liquid crystal molecules. Moreover
the content of surface side chains of this PI films before rubbing is the same as that after rubbing.
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