THE SYNTHESIS OF MESOGENIC POLYMERS PROVOKED BY MOLECULAR MOBILITY - POLYSILOXANARYLENES

An approach to the synthesis of potentially thermotropic liquid crysta lline polymers based on parallel investigation of their molecular mobi lity was realized. The initial idea was provoked by the observation th at there exists some correspondence of molecular mobility data and the ability of a polymer to form a liquid crystalline phase. Previously t his phenomenon was demonstrated on the example of a series of thermotr opic main chain polymers with flexible dimethylsiloxane spacers of var iable length. The relation between the structure of the main chain and local molecular mobility of different fragments was investigated in a series of regular polysiloxanesilarylenes containing rigid aromatic s equences. Molecular mobility was studied by dielectric spectroscopy in solution and in solid state. The structure of the main chain has been changed by variation of the repeated fragments' length, substituents and joint groups, The data of molecular mobility and their conformity with the chain structure were used for directed synthetic search of de sired mesogenic polymers.