Electrooptical and dielectric properties of comb-shaped mesogenic polymersin solutions and nematic melts

A comparative study of the electrooptical end dielectric properties of the dilute solutions and nematic melts of two comb-shaped mesogenic polymers wa s performed by the methods of electric birefringence and orientational elas tic deformations in electric fields. For one of the polymers, an abnormal t emperature dependence of the threshold electric potential of nematic deform ation with a well-pronounced maximum was observed. It was shown that this m aximum is related to the occurrence of an extremum on the temperature depen dence of the orientational elasticity constant caused by fluctuations of sm ectic order in the polymeric nematic.