Abstract: The flame-retardant polyester was synthesized by TPA, EG and 2-carboxy ethyl phenyl phosphinic acid glycol ester zinc salt (CEPPA-Zn). Polycondensation reaction time is shortened and condensation polymerization temperature is reduced due to the flame retardant agent exist. The thermal behaviors were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and shown that flame retardant polyester glass transition temperature, crystallization temperature and melting point were increased, and thermal stability of the samples was enhancement because of the presence of flame retardant, and the quantity of carbon residue was increased due to the Zn ionic. The flame retardant properties of the resulting copolyesters were characterized by limiting oxygen index(LOI) test and it was shown that the copolyesters had good inherent flame retardancy, and the LOI value raised to 36.7 when the flame retardant content reached 7 %.

Key words: ionic flame retardant CEPPA-Zn, flame retardant copolymerization, LOI, charrring