A LIQUID-CRYSTAL BASED POLYMER FOR APPLICATIONS IN MMW MODULATION DEVICES

A new liquid crystal monomer, the diacrylate of a bis phenyl diazene, was synthesized. It was polymerized to form both unoriented and orient ed polymer solids - the latter in the presence of a magnetic field. Th e millimeter wave birefringence was measured for a polymeric rod, whos e macroscopic orientation was perpendicular to its long axis, using a waveguide version of the Mach-Zehnder interferometer, and the measured Delta n was 0.075 at 30 GHz. The mechanical strength of oriented and unoriented polymer plates was measured. The tensile modulus in the dir ection parallel to the oriented axis was 6.8 x 10(8) N/m(2), which was about 4 times that of the same material without macroscopic orientati on. The torsional rigidity modulus of a thin rod (orientation perpendi cular to its length) was measured to be of the order 10(7) N/m(4). Bot h the large dielectric anisotropy and high mechanical strength make th e oriented polymer potentially suitable for application in a novel cla ss of millimeter wave modulation devices.