高纯度聚酯原料对苯二甲酸二甲酯的合成

Synthesis of polyester material of high-purity dimethyl terephthalate

以羧酸、酰氯化试剂和甲醇为原料,制备了高纯度对苯二甲酸二甲酯,得出合适的反应物料比为:m(氯化亚砜)∶m(对苯二甲酸)=3.0∶1、m(甲醇)∶m(对苯二甲酰氯)=2.9∶1,催化剂DMF的质量分数为对苯二甲酸质量分数的2.1%,反应温度55~105℃,合成压力94.8~96.8 k Pa。在优化工艺条件下,所制备的产品纯度>99.90%。产品经熔点测定仪、红外光谱仪和核磁共振仪确证。

Dimethyl terephthalate was prepared in two steps based on the raw materials of terephthalic acid, thionyl chloride and methanol. The optimization of process conditions are m（Thionyl Chloride）∶m（Terephthalic Acid）=3.0∶1、m（Methanol）∶m（Terephthaloyl Chloride）=2.9∶1, The catalyst quality of DMF is about 2% of the quality of terephthalic acid, reaction temperature 55~105 ℃, synthetic pressure about 94.8~96.8 k Pa. Under optimum conditions, the prepared product purity is higher than 99.90%. The product was confirmed by melting point apparatus, FTIR and 1H-NMR.