相转移催化制备环氧大豆油的工艺研究

Investigation into Preparation Technology of Epoxidized Soybean Oil via Phase-Transfer Catalysis

目前工业上利用过酸生产环氧大豆油(ESO)会造成严重的环境污染,因此有必要探索绿色的ESO制备工艺.文中以H2O2为氧源,利用响应面分析法建立数学模型,优化由相转移催化剂催化的ESO的制备工艺,并对制得的ESO进行理化性质分析、热稳定性分析及红外表征.结果表明,在最佳制备工艺条件(即双氧水、催化剂、聚乙二醇、大豆油的质量比为87∶29∶30∶100,加热温度为55℃,加热时间为3.5 h)下,ESO环氧值的模型预测值为6.48%,而实测值为6.40%,所建立的ESO响应面模型可以用于指导ESO的制备.实验所得的ESO符合国家行业标准,且制备条件温和,反应时间较短,并具有较好的热稳定性(在177℃下处理3.0 h,环氧值下降率仅为0.48%).红外表征结果证实,大豆油经选择性氧化后,不饱和双键转化为了环氧键.

At present,the industrial application of per-acid to the production of epoxidized soybean oil( ESO) can lead to serious pollution,so it is necessary to explore the preparation technologies of green epxidized soybean oil.In the investigation,by taking H2O2 as the oxygen source,a mathematical model on the basis of the response surface methodology was constructed to optimize the preparation technology of ESO obtained through phase-transfer catalysis. Then,the prepared ESO was characterized by means of FT-IR,and its physical and chemical property and thermal stability were also analyzed. The results show that,under the optimal conditions,namely,a mass ratio of H2O2,catalyst,PEG and soybean oil of 87∶29∶30∶100,a temperature of 55℃ and a reaction time of 3. 5h,the predicated epoxy value of ESO,which is 6. 48%,is close to the tested value of 6. 40%,which means that the proposed model on the basis of the response surface methodology can be used to guide the preparation of ESO.The prepared ESO with mild reaction conditions and short reaction time meets the national industry standard,and it is of a better thermal stability,specifically,its epoxy value decreases only by 0. 48% with a processing time of3. 0 h at 177 ℃. The results of IR confirm that the unsaturated double bonds are converted into the epoxy bonds after the selective oxidation of soybean oil.