聚合物结构对PDLC性能的影响

Effect of Polymer Structures on Electro-optical Properties of Polymer Dispersed Liquid Crystals

用光聚合诱导相分离法制备了3种不同聚合物基体的聚合物分散液晶(PDLC)膜,研究了液晶含量和固化时间对PDLC透光率及膜形态的影响,考察了不同聚合物基体对PDLC电光性能的影响。结果表明,聚合物单体反应活性越高,达到关态下最低透过率所需的固化时间越短,丙烯酸仅需10 s,而甲基丙烯酸甲酯却需360 s;聚合物与液晶颗粒之间的相互作用越强,PDLC膜的阈值电压越高,丙烯酸的阈值电压至少是其他两者的5倍。

PDLC films were prepared by PIPS with three different kinds of polymer matrices, such as poly （acrylic acid）, poly（methyl acrylate） and poly（methyl methacrylate）. The effects of liquid crystal concentration and curing time on morphologies and transmittance of PDLC were studied. In addition, the influence of different polymer structures on the electro-optical properties was specially researched. It is found that the reactive monomer required shorter curing time for reaching the smallest OFF state transmittance. Only 10 s was enough for acrylic acid, but 300 s was necessary for methyl methacrylate. Otherwise, with an increase of the interaction between polymer matrix and liquid crystal droplets, the threshold voltage for PDLC films became higher. The threshold voltage of PDLC of poly（acrylic acid） was at least 5 times as high as that of poly（methyl methacrylate） and poly（methyl acrylate）.