Abstract
Liquid crystalline hyperbranched poly(aryl ester)s (A(2)B(3)) were prepared by polycondensation reaction of 2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)1,4-naphthalene diol with 1,3,5-benzenetricarbonyl trichloride, taken in two different molar ratios. The chemical structure of the newly synthesized hyperbranched polymers was confirmed by FTIR,H-1 NMR,C-13 NMR spectroscopy. The polymers exhibited high thermal stability with initial decomposition temperature above 410-435 degrees C and char yield at 700 degrees C higher than 40%. Combined differential scanning calorimetry, polarized optical microscopy and wide-angle X-ray diffraction measurements were carried out to closely examine their thermal behavior and phase transitions.