Research Article

Optimization of Process Variables in the Synthesis of Tributyl Citrate Using a Polyvinylpolypyrrolidone-Supported Brønsted Acidic Ionic Liquid Catalyst

Figure 1

Effect of the n-butanol to citric acid molar ratio on the esterification of citric acid with n-butanol. Reaction conditions: citric acid, 0.06 mol; n-butanol, 0.3 mol; catalyst, 6 wt%; temperature, 115°C; time, 5 h.