Polyesters with silanes in their main chains were synthesized．These polyesters possess interesting pmporties such as hish thermal stability

oxidative stability

low surface energy

water repellency and good dielectric properties．Thermal properties of these silane—containing polyesters were tested by differential scanning calorimety (DSC)and thermal gravimetric analysis(TGA)．The results show that the polyesters without substitutents have exeeUent thermal stability and excellent chemical resistance．While polyesters with substituents have good solubility in polar organic solvents such as THF

DMF

DMSO

NMP

DMA and could be made into membrane material easily．These novel silane--containing polyesters could be processed as conveniently as other thermo-plastics and have high application temperature．