对苯二甲酸与丁二醇和乙二醇直接酯化的研究

研究了对苯二甲酸（ＰＴＡ）直接酯化法合成对苯二甲酸丁二醇酯－对苯二甲酸乙二醇酯（ＢＨＢＴ－ＢＨＥＴ）时影响主、副反应的诸项因素以及副反应产物四氢呋喃（ＴＨＦ）的生成规律，提出了抑制ＴＨＦ生成的方法．在合成ＢＨＢＴ－ＢＨＥＴ时，以硫酸钛水解物为催化剂具有较好的效果，催化剂浓度、酯化反应温度及二醇／ＰＴＡ的摩尔比等对主、副反应有较大影响，酯化反应体系的酸性是促进副反应的重要因素，添加适量的碱性物质可有效地控制ＴＨＦ的生成．

Study on Direct Esterification of PTA with BG and EG

The factors that affect the primary and side reactions in synthesizing Bis- hydroxybutyl terephthalate/bis-2-hydroxyethyl terephthalate (BHBT-BHET) by PTA d itect esterification are studied. The rule of forming THF,product of side reaction,is discussed as well. The authors pointed out that when hydrolyzates of titanium sulfate are used as catal. ysts in the synthesis of BHBT-BHET, the reaction can be more efficieat. Concentration of catalyst, temperature of esterification and molar ratio of diol/PTA have remarkable innuences on the primary and side reaction. The acidity of esterification is an important factor in enhancing the side reaction. The authors found that by adding adequate amount of alkalinous substances, the forming of THF can be controlled.