Flame Retardant Copolyesters Containing Phosphorus Linked Pendent Groups Research

The flame retardant copolyesters containing phosphorus linked pendent groups, derived from 9,10-dihydro-10 [2,3-di (hydroxycarbonyl) propyl] 10-phosphaphenanthrene-10-oxide (DDP), terephthalic acid (TPA) and ethylene glycol(EG),were synthesized by melting polycondensation. Their structures were characterized by FT-IR, Mass Spectroscopy and Nuclear Magnetic Resonance Spectroscopy. The basic properties, such as thermal behavior, thermal stability, crystallinity and thermal degradation kinetic were investigated by differential scanning calorimetry(DSC), thermogravimetry analysis(TGA)and wide-angle X-ray diffractionmetry (WAXD).The copolyesters possess good flame retardancy , the LOI can reach 28.8-33, and Grade FV-2 is obtained in the vertical burning test. Owing to the incorporation of the phosphorus pendent groups, the copolyesters have good thermal stability at the same time. And because of soft structure of -CH2 in the monomer, Tg and Tm values of the copolyesters are decreased.