Antiferroelectric domains in liquid crystalline methacrylic polymers

The preparation of several liquid crystalline polymers obtained using different AIBN concentration and polymerization times are reported. The compounds were characterized by 1H NMR, differential thermal analysis (DTA), X-ray diffraction and pyroelectric measurements. For all polymers, a smectic C2 phase occurs over broad temperature range, where the molecules adopt an opposite tilt direction for alternate smectic layer. Crystalline polymers show an antiferroelectric behavior, developing an anticlinic phase responsible for the electric behavior. The arrangement of the side chain molecules within the partial crystalline network in these electrically active polymers is related with the kinetic of precipitation.