液相空气氧化合成均苯三甲酸

研究了常压下,采用液相空气氧化法,由均三甲苯制取均苯三甲酸的反应工艺,通过对催化剂用量、反应温度、反应时间、溶剂用量等因素的考察,确定出最佳工艺条件:n(均三甲苯)∶n(冰醋酸)∶n(醋酸钴)∶n(溴化钠)∶n(无水乙酸钠)=1∶35∶0.2∶0.1∶0.05,反应温度95℃,反应时间4.5 h,空气流速0.06 m3/h。均苯三甲酸收率43.56%,酸值以KOH标准为752.39 mg/g,产品质量纯度为96.46%。该工艺具有原料价廉易得、产品含量较高的特点,对工业化生产有指导意义。

Synthesis of trimesic from liquid-phase oxidation by air

The preparation of trimesic from mesitylene by air in a liquid-phase oxidation under normal pressure was studied.The effects of reaction conditions,such as catalyst consumption,reaction temperature,reaction time and solvent were investigated.The results show that the optimum conditions are that:n(mesitylene) ∶n(acetic acid) ∶n(cobalt acetate) ∶n(sodium bromide) ∶n(sodium acetate)=1 ∶35 ∶0.2 ∶0.1 ∶0.05;the reaction takes place at 95 ℃for 4.5 h,the velocity of air is 0.06 m3/h.Under these conditions the trimesic yield can reach 43.56%,with 752.39 mg/g of trimesic′s acid value and 96.46% of mass purity.The process makes features of cheap raw material and high content of the product.Therefore,it can direct the industrial production.