Synthesis and Properties of some Phosphorus-containing Polyesters

Phosphorus-containing polyesters were prepared by polycondensation of 2-(6-oxido-6H-dibenz >c,e< >1,2< oxaphosphorin-6-yl)-1,4-benzenediol with different aromatic dicarboxylic acids using a SOCl 2 /pyridine condensing agent. The polymers were soluble in polar organic solvents such as N-methylpyrrolidone, N, N-dimethylformamide, tetrahydrofuran and chloroform. They showed high thermal stability having a decomposition temperature above 360°C and char yield at 700°C in the range of 19-32%. The glass transition temperature was in the range of 180-194°C. Solutions of the polymers in N, N-dimethylformamide showed fluorescence having maximum emission wavelength around 362 nm. One of the polymers exhibited thermotropic liquid crystalline behavior