A series of main chain liquid crystalline copolyesters with X-shaped two—dimensional mesogenic units and crown ether cycles of trans-4

4’-bis(4-hydroxyphenylazo)dibenzo-18-crown-6 was synthesized via solution cocondensation polymerizations from 4

4’-(α

ω-hexanedioylxy)dibenzoyl dichloride(M1)

2

5-bis(P-octyloxybenzoyloxy)hydroquinone(M2)and trans-4

4'-bis(4-hydroxyphenylazo)dibenzo-18-crown-6(M3)as the monomers．The molecular weights of copolyesters are not high

and the[η]of the copolyesters ranges from 0．37～0．25 dL／g．The monomer structures were identified by using elementary analysis

IR

UV

1H—NMR and MS etc．All the copelyester samples are yellowish powders and insoluble at room temperature in THF and CHCl3 except sample CP9 The properties of eopolyestars were investigated by using GPC

[η]

DSC

TG

WAXD and POM．It was found that all the copolyesters went into liquid—crystal phase when they were heated over their melting temperature(Tm)．In their liquid crystalline state

the typical mosaic texture or focal—conics texture or broken fan texture of smectic phase

and ball granul texture or thread texture or schlieren texture of nematic phase can be observed．Their melting temperature and isotropization temperature(Ti)changed regularly with varying the trans-4

4'-bis(4-hydr-oxyphenylazo)dibenzo-18-crown-6 unit content in the copolyesters．The WAXD studies also evidenced the liquid crystallinity of these copolyesters.