SYNTHESIS OF POLYESTERS CONTAINING AN AROMATIC TRIAD MESOGEN

Thermotropic liquid crystalline polymers containing bis(p-oxybenzoyl t erephthalate) (Triad) mesogen units linked by flexible polymethylene u nits were prepared by melt and solution polymerization reactions. Anal ogous Triad polymers based on a central isophthalate group were also p repared, but these polymers, which contained non-linear rigid segments , did not exhibit liquid crystalline behaviour. Copolymers composed of a mixture of linear and non-linear Triad units were also evaluated. I n addition, a series of random Triad copolymers that contained butylen e terephthalate (BT) units were also synthesized in solution. The liqu id crystalline behaviour of these copolymers depended on the relative number of BT moieties present.