Abstract: The titanium catalyst has excellent catalytic activity for polyester synthesis and is non-toxic, which is being widely studied and applied. This paper starts with the main chemical reaction of the polyester synthesis process, points out that based on research the catalytic chain growth reaction activity of titanium catalyst is high, and catalyzed the thermal oxidation degradation of polyester at the same time can cause PET’s color to be yellowed. The addition of suitable antioxidants to polyester synthesis can effectively inhibit thermal oxidation degradation. And the pre-preparation of titanium catalysts to be soluble with phosphatic compounds in place with glycol complex can control the catalytic activity of titanium atoms in moderation, which can inhibit its thermal oxidation degradation and improve PET’s hue of color.

Key words: polyethylene terephthalate; titanium catalyst; thermal oxidation degradation; antioxygen