A new photosensitive polyimide (PI) was successfully synthesised via esterification of PI containing hydroxyl groups with cinnamoyl chloride (CL). The cinnamate (CA) group contents of the P...

Synthesis of photosensitive polyimide for liquid crystal alignment under non-polarised UV ageing lamp irradiation and a study on the possible mechanism of alignment

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,...

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

In order to reduce the cost, a polyimide (BF-CA) with high photosensitivity and low solid content was prepared by one-step method using 2,2-bis (3-amino-4-hydroxyphenyl) propane (BAP), 4,4ʹ- (hexaf...

Preparation of polyimide alignment films with high photosensitivity and low solid content

In order to obtain liquid crystal alignment films with better photosensitivity, transmittance and solubility, a ternary copolymer polyimide (BFB-PI-CA) is synthesised by benzophenone-3, 3′, 4, 4′-t...

Preparation of a novel ternary photosensitive polyimide for liquid crystal alignment films

In order to study the impact of the flexibility of photosensitive polyimide (PI) backbone on the properties of liquid crystal (LC) alignment under non-polarised ultraviolet light (NPUVL), two kinds...

The impact of the flexibility of photosensitive polyimide backbone on the properties of liquid-crystal alignment under non-polarised ultraviolet light

A photoreactive polyimide, bearing a cinnamate photoreactive moiety in its side group, was synthesized. The photochemical reactions of the PSPI in the films were investigated in detail by UV-Vis and IR spectroscopies; the cinnamate chromophores were confirmed to undergo photodimerization. Linearly polarized ultra-violet light irradiation induced anisotropic reorientations of both the polymer main chains and the side groups in the film. The PSPI thin films were found to have unidirectional orientation ability as a result of photo-exposure with linearly polarized ultraviolet light, with the photoaligned polymer chains in the PSPI films able to effectively induce the alignment of nematic liquid crystals.

Young Hoon Min

Papers

Synthesis, Characterization, and Liquid Crystal Alignment Properties of Photosensitive Polyimide