| Polymer dispersed liquid crystals (PDLC) were prepared by liquid crystal droplets dispersed within polymer matrix. In PDLC film, the polymer provides a stable cross-network structure for liquid crystal droplets and electro-optical properties of films strongly influenced by polymer network structure. The monomer structure and formed polymer network structure have a great impact on the electro-optical properties of PDLC.In this paper, a mesogenic diacrylate monomer 4,4'-bis[6-(acryloyloxy)hexyloxy]biphenyl (BAB6) was synthesized by two routes. Route 1, which was the traditional method for synthesizing acrylic polymer dispersed liquid crystal (PDLC) monomer, was carried by 4,4'-bis[6-(bromo)hexyloxy]biphenyl reacting with potassium acrylate. In Route 1, the intermediate product had poor solubility, the reaction temperature of route 1 is higher than that of route 2, the target product of route 1 behaved light yellow color and the yield was only 12.4 %. While in route 2, BAB6 was obtained by the reaction between 4,4'-bis[6-(hydroxyl)hexyloxy]biphenyl and acryloyl chloride. The solubility of intermediate product in route 2 was higher than that of route 1. In route 2, the process is reacted at room temperature. The product appeared white, and the yield could be improved to 46.8%. BAB6 was characterized by 1H-NMR, 13C-NMR and elemental analysis.The polymer dispersed liquid crystals (PDLC) films was prepared subsequently using BAB6 as monomer. The effects of BAB6 concentration, curing temperature and UV light intensity to the morphology of polymer network were researched. And then the morphology of polymer network was investigated by SEM.Further, electro-optical properties of the PDLC films were studied by changing BAB6 concentration, chiral dopant concentration and curing temperature. The fast response PDLC film was obtained by using BAB6 as monomer, response time about 2ms.
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