Method for preparing polyester for reducing content of diethylene glycol in polyester

A method for preparing a polyester for reducing the content of a diethylene glycol in the polyester includes (a) subjecting a mixture formed by bis-PET and an aromatic polycarboxylic acid compound toan esterification reaction to obtain an esterified product, and (b) subjecting the esterified product to polycondensation. The polyester preparation method can effectively reduce the diethylene glycolcontent in the polyester, and the obtained polyester has a better heat-resistant property. 种降低聚酯中二甘醇含量的聚酯制备方法，包含以下步骤：(A)使由双-对苯二甲酸乙二醇酯及芳香族多元羧酸化合物所组成的混合物进行酯化反应并得到酯化产物；及(B)使所述酯化产物进行缩聚合反应。所述聚酯制备方法能有效降低聚酯中的二甘醇含量，所制得的聚酯具有较佳的耐热解性质。