THERMOTROPIC COPOLYESTERS HAVING ORDERED COMONOMER SEQUENCES AND FLEXIBLE SPACERS

A series of new copolyesters having ordered comonomer sequences were synthesized via multistep routes and their properties such as glass transition (T(g)) and melting temperatures (T(m)), crystallization tendency, and mesomorphic properties were compared with those of the corresponding random copolyesters. All of the present copolyesters contain 1,8-octamethylene or 1,10-decamethylene spacers and hydroquinone (HQ) and terephthalic acid (TPA) moieties. In general, both melting and clearing temperatures of the ordered sequence copolyesters were much higher than those of the random counterparts. Crystallization tendency, however, was comparable. All of the present copolyesters are thermotropic and form nematic phase in melts.