Liquid crystalline hyperbranched polyesters with phosphorus functional groups

Liquid crystalline hyperbranched poly(aryl ester)s (A(2)B(3)) were prepared by polycondensation reaction of 2-(6-oxido-6H-dibenz<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.

Automated summary

Liquid crystalline hyperbranched poly(aryl ester)s were synthesized with high thermal stability and char yield, and their chemical structure was confirmed by various spectroscopic techniques.