环保增塑剂环己烷1,2-二甲酸二异辛酯的合成

以环己烷1,2-二甲酸酐(HHPA)和异辛醇为原料,活性炭负载甲烷磺酸为催化剂,合成环己烷1,2-二甲酸二异辛酯。经单因素实验得到最佳工艺条件为:n(异辛醇)∶n(环己烷1,2-二甲酸酐)=2.4∶1.0,催化剂用量为醇酐总质量的2.1%,带水剂环己烷用量6 mL,反应温度160～180℃,反应时间2.5 h,酯化率可达99.82%。催化剂重复使用4次后酯化率仍大于90%。产品为浅黄色油状液体,经HPLC测定酯色谱纯度为99.15%。测定了其酸值、密度、加热减量、黏度、热重曲线等,结果表明,环己烷1,2-二甲酸二异辛酯符合增塑剂的性能要求。

Synthesis of Environmentally-friendly Plasticizer Di(2-ethylhexyl) 1,2-cyclohexane Dicarboxylate

Di(2-ethylhexyl) 1,2-cyclohexane dicarboxylate(DEHCH) was synthesized through reaction of HHPA with iso-octanol using active carbon supported methanesulfonic acid as catalyst.The optimal reaction conditions are as follows:n(iso-octanol)∶n(HHPA)= 2.4∶1.0,catalyst(2.1% of mass of HHPA and iso-octanol),water entrainer cyclohexane 6 mL,reaction temperature 160～180 ℃,reaction time 2.5 h.The esterification yield is 99.82%.The esterification rate was still more than 90% after the catalyst was repeatedly used for 4 times.The product is light yellow transparent oily liquid and the content of DEHCH ranges up to 99.15% by means of HPLC test.The acid value,density,heat weight loss,viscosity and TG curve of the product were respectively measured.In conclusion,DEHCH can satisfy the requirements of plasticizer.