STUDIES ON MISCIBILITY AND MORPHOLOGICAL FEATURES OF BLENDS OF LC COPOLYESTER AND PET

The morphology of a special blend system composed of liquid crystalline aromatic random copolyester (LCP) and semiflexible polyester PET over the whole composition range has been studied by means of polarized microscope, density measurement, DSC, FTIR and SEM. Based on the microscopic observation, it is found that under suitable mechanical mixing condition, LCP may be rather homogeneously dispersed in the PET matrix, with the middle composition range of the contents of LCP at 30--70 wt % the anisotropic and isotropic phase segregation appears.while with LCP contents over 80 wt% the blends exhibit wholly anisotropic.The DSC thermographs of the melt-pressed and quenched films show single Tg,Tcc and T m,Tg increases with increasing with increasing content of LCP and approaches to the Tg of pure LCP.The experimental results indicate that the two components of this blend system are miscible,there exist some specific interactions between them.