A new kind of liquid crystalline Polyestercarbonates with chain structure-(OPhCO)x-(OPhC(CH3)2 phOCO)y-were synthesized for the first time by using polymer modification method. The liquid crystalline properties were studied by 1H-NMR

FTIR

DSC

TGA

POM and X-ray diffraction. The results showed that Polyestercarbonates with higher inherent viscosities can be obtained by using of PPHB as one kind of raw materials and the polymers exhibit nematic thermotropic liquid crystalline behavior as the content of p-oxybenzoate units increases from 55mol% to 65mol%.PC/60PHB has good thermostability and will not degrade until 380 ℃.