Design,Synthesis And Properties Of New-type Fluorescent Liquid Crystalline Polymers Bearing α-Cyanostilbene

Luminescent liquid crystal materials combine the luminescent properties of luminescent materials and the liquid crystal properties of liquid crystal materials.They have important application value in the fields of luminescent liquid crystal display,optical information storage,organic light-emitting diodes,and have attracted continuous attention.Although luminescent liquid crystal materials have great application prospects,there are still big challenges in their design and synthesis.Up to present,most of the reported luminescent liquid crystal materials have concentration quenching effect,which makes it difficult to integrate the luminescent property and liquid crystal property in a one molecule.In this paper,two new-type luminescent liquid crystal polymer materials,mesogen-jacketed type and side chain type,were designed and synthesized using α-cyanostilbene with AIEE properties as luminescent liquid crystal unit.Various characterization methods were used to study their phase structure,photophysical properties and stimulus response properties in detail.The work of this paper is mainly divided into the following two parts:1.Two new-type luminescent mesogen-jacketed liquid crystal monomers,(2Z,2’Z)-3,3’-(2-vinyl-1,4-phenylene)bis(2-(4-(hexyloxy)phenyl)acrylonitrile)(M1)and(2Z,2’Z)-3,3’-(2-vinyl-1,4-phenylene)bis(2-(4-(tetradecyloxy)phenyl)acrylonitrile)(M2)were designed and synthesized,and the corresponding polymers P1 and P2 were obtained by solution-bulk polymerization.Their terminal groups are hexoxy and tetradecanoxy,respectively.The phase structure,thermal stability and photophysical properties of monomers and polymers were studied in detail.The result shows that the polymers have good thermal stability;the monomers and polymers have liquid crystal properties,in which the polymers form columnar nematic liquid crystal;the monomers and polymers show AIEE properties,and the polymers have high fluorescence quantum yield;the polymers show photoresponse performance in both the solution and film states.2.Two side chain luminescent liquid crystal polymers,poly(Z)-6-(4-(1-cyano-2-(4-(dimethylamino)phenyl)vinyl)phenoxy)hexyl methacrylate(PM6CS-DMA)and poly(Z)-6-(4-(1-cyano-2-(4-(dibutylamino)phenyl)vinyl)phenoxy)hexyl methacrylate(PM6C S-DBA),were designed and synthesized.Their terminal groups are dimethylamino and dibutylamino,respectively.The phase structure,thermal stability,photophysical properties and p H response performance of polymers were studied in detail.The results show that the polymers have good thermal stability,AIEE property and liquid crystal property,and nematicliquid crystal is formed in both polymers.At the same time,both polymers show reversible p H response performance.