Synthesis and characterization of new flame-retardant polyaryl phosphoramide esters containing furan and thiophene units

Two series of new flame-retardant polyaryl phosphoramide esters were synthesized by low-temperature solution polycondensation from arylphosphorodichlorides with 3,4-bis(4-ami-nophenyl)2,5-diphenylfuran and 2,5-bis(4-aminopheny1)3,4-diphenylthiophene. The polymers were characterized by IR, 1H, 13C, and 31P NMR spectroscopy and elemental analysis. The thermal stability and flammability were studied by thermogravimetry and limiting oxygen index, respectively