Novel liquid-crystalline mesogens and main-chain chiral smectic thiol-ene polymers based on trifluoromethylphenyl moieties

The synthesis and characterization of a series of novel liquid-crystalline molecules containing a trifluoromethylphenyl core or a 2,3-bis(trifluoromethyl)phenyl core is described. All trifluoromethylphenyl-containing compounds (W530, W551, and W558) have mesomorphic properties while 2,3-bis(trifluoromethyl)phenyl-containing compounds (W555, W556, W557) are room-temperature crystals without mesophases. Thereafter, based on the chemical structure of W558, to pursue a mesogen with a large electroclinic effect in the SmA* phase for development into electromechanical actuators, a chiral smectic thiol-ene monomer (K0901) is synthesized and polymerized in organic solvents. The polymer is characterized by GPC, DSC, PLM, XRD and shows an expected I–SmA* –Glass phase sequence though the electroclinic effect is relatively small.