When the copolyester contains 10%, 15%, or 50% (mol) isophthalic acid, it displays the optical property of the thermotropic mesomorphicphase;
当间苯二甲酸的含量为10％、15％和50％（摩尔）时，共聚酯显示出热致性中介相的光学性质。
2
The influence of the number of carbon atoms in flexible spacer on their mesomorphic state, clear temperature, phase-transition temperature is studied by using of DSC.