Preparation and performance analysis of novel liquid crystal alignment films based on macromolecular photosensitiser and photosensitive polyimide

A photosensitive polyimide (BF-CA) and a macromolecular photosensitiser (BB-CA) are successfully synthesised. The BF&BB-CA blend films based on BF-CA and BB-CA can induce uniform alignment of liquid crystal (LC) after the non-polarised ultraviolet light (NPUVL) exposure for 15 min. After exposure for the same time, LC alignment ability of the BF&BB-CA blend films is higher than that of BF-CA films and BB-CA films. The alignment performance of LC and pretilt angles induced by the BF&BB-CA films after treatment at 120 degrees C for 4 h are nearly unchanged, indicating that the prepared films have excellent thermal stability. Furthermore, the pretilt angle of the LC cells is 0.5 degrees, which can be used in In-Plane Switching mode LCD.

Automated summary

Photosensitive polyimide (BF-CA) and a macromolecular photosensitiser (BB-CA) were successfully synthesized to form BF&BB-CA blend films, which can induce uniform alignment of liquid crystal (LC) after 15 minutes of non-polarised ultraviolet light exposure. The films exhibit higher LC alignment ability and excellent thermal stability, with a pretilt angle of 0.5 degrees suitable for In-Plane Switching mode LCD.