环保增塑剂环己烷1,2-二甲酸二异辛酯的合成

Synthesis of Environmental Plasticizer Di(2-Ethylhexyl) 1,2-Cyclohexane Dicarboxylate

以1,2-环己二甲酸和异辛醇为原料,浓硫酸为催化剂,酯化合成环保增塑剂环己烷1,2-二甲酸二异辛酯,考察了反应时间、醇酸物质的量比、反应温度等对酯化率的影响,并对产物进行了1 H-NMR、IR、TG及气相定性分析。结果表明,反应时间6h,反应温度170℃,醇酸物质的量比为2.5∶1时,酯化率可达99.5%,收率95%,产品为无色油状液体。核磁氢谱显示与酯基相连的亚甲基的多重峰信号δ在4.0处,红外谱图显示酯羰基的伸缩振动峰出现在1 735cm-1处,这些结果表明得到了预期产物。产物的TG曲线显示其外延起始温度为215℃,其气相出峰时间为14.310min和14.505min,能够与邻苯二甲酸二异辛酯(DOP)有效分离。

Environmental plasticizer di（2-ethylhexyl） 1,2-cyclohexane dicarboxylate was synthesized through esterification reaction of 1,2-cyclohexanedicarboxylic acid （CHDA） with iso-octanol using concentrated sulfuric acid as catalyst. Effects of reaction time, ratio of alcohol to acid and temperature on esterification rate were investigated. Under optimal reaction conditions： 6 h, 170 ℃, n（alcohol）/n（acid） = 2.5 ： 1, esterification rate and yield mount to 99.5% and 95%, respectively. The product was colorless transparent oily liquid. In the 1 H-NMR spectra, the multiplet for the -COOCH2 appeared at 3= 4.0. IR spectra exhibited u（C = O） band at 1 735 cm-1. The results demonstrate the target product was synthesized. TG curve shows that initial temperature was 215 ℃. Also, a method for qualitative analysis was established, the retention time of the product were 14. 310 min and 14. 505 min, which can separate from DOP effectively.