Synthesis of PET and Its Copolymer with Rare Earth Catalysts

A new catalyst system was used in the synthesis of polyethylene terephthalate(PET) and its copolymers, which involved a Ln3+ containing compound. The catalytic effects were studied, and it was found that the direct esterification reaction of terephthalate acid(TPA) with ethylene glycol(EG) can be accelerated by the addition of Ln3+ containing compound, which acts as a promoter of the catalyst Sb2O3 in polycondensation of bis hydroxyethyl terephthalate(BHET).