Preparation and alignment properties of photosensitive polyimide containing benzophenone in main chain

ABSTRACT

In order to study the effect of benzophenone (BP) group in the main chain on the photo-alignment behaviour of cinnamoyl groups, a novel photosensitive polyimide (BTDA-PI-CA) is synthesised by 3,3ʹ,4,4ʹ-benzophenonetetracarboxylic dianhydride (BTDA), 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (AHHFP) and cinnamoyl chloride. The BTDA-PI-CA films exhibit good alignment performance after the non-polarised ultraviolet ageing lamp exposure, which is due to the polyimide with BP group can be used to improve the photosensitivity. Moreover, the thermal stability of the LC cells is pretty good and the pretilt angle of the LC cells is 0.5, which can be used in parallel mode LCD.

Graphical abstract

KEYWORDS:

• Benzophenone
• photosensitive polyimide
• non-polarised ultraviolet
• alignment properties

Disclosure statement

No potential conflict of interest was reported by the authors.