THE THERMAL-DEGRADATION OF PHOSPHORUS-CONTAINING COPOLYESTERS

Two series of phosphorus-containing copolyesters were synthesized by p olycondensation of phosphorus-containing monomers: poly(ethylene terep hthalate)-co-poly(ethylene phenylphosphonate)s [PET-co-PEPPs] and poly (ethylene terephathalate)-co-poly(ethylene DDP)s [PET-co-PEDDPs]. Both series are considered as flame retardants in polyester fibers and pol yester plastics. The phosphorus-containing polymers were characterized by NMR, IR, TGA and acid titration. Experimental results indicated th at for the PET-co-PEPP higher phosphorus content results in lower ther mal stability. However, an insignificant effect on thermal stability w as observed in the case of PET-co-PEDDPs. Thus, the incorporation of t he phosphorus linkage into the main chain results in less thermal stab ility than that having the phosphorus linkage as a pendant group, i.e. PET-co-PEDDPs are more stable than PET-co-PEPPs. (C) 1996 Elsevier Sc ience Limited