The liquid crystalline copolyester (LCP)/montmorillonite nanocomposites were prepared by polycondensation of terephthalic acid

p-acetoxy benzoic acid and 1

2-diacetoxy benzene

in the presence of an organically modified montmorillonite(OMt) with p-aminobenzoic acid hydrochloride.The cleavage effect of OMt and the liquid-crystalline behavior of the composites were described. The cleavage effect of OMt was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM).Room-temperature XRD spectra were collected from 20=2°to 20=10°.The eventual disappearance of any distinct X-ray diffraction peaks for the hybrid containing 2

3

or 5wt% OMt indicated the well dispersion of its original layer structure. The TEM micrograph showed that the silicate layer spacings were greater than 3nm

even some layers dispersed in polymer matrix individually. The glass transition temperature Tg of the LCP/OMt nanocomposites increased slightly as compared with the pure polymer

but the isotropic temperatues Ti decreased moresignificantly as the content of OMt increased.As the clay content increased up to 3%

the decrease of Ti reached 25℃ LCP chains separated in certain degree by inorganic phase decreased the ordering ability of mesogenic units.This may be the principal reason for the descent of Ti. The nematic texture of nanocomposites was observed by POM

and the schlieren texture became indistinct as the clay content increased.Although the schileren texture in POM for the hybrid with clay content up to 5% still could be observed

the evident location of disinclination point already can't be found.Thus

the mechanism of disinclination in nematic phase for LCP hybrid with OMt is more complicated thean that for pure polymer.