Preparation method of high-purity dioctyl phosphate

The invention provides a preparation method of high-purity dioctyl phosphate, which comprises the following steps: taking octanol and water as solvents, adding phosphoric acid mixed octyl ester and solid alkali which is 1.1-1.35 times of theoretical quantity required by alkaline hydrolysis of the phosphoric acid mixed octyl ester, performing high-temperature alkaline hydrolysis, and performing acidification reaction twice to obtain the high-content and high-purity dioctyl phosphate. According to the method, the dosage of the solid alkali is reduced, a phase transfer catalyst does not need to be added, the steps are simple, the reaction conditions are mild, the energy consumption is low, the reaction period is short, the content of the obtained dioctyl phosphate is larger than 93%, and the purity is high. 本发明提供了一种高纯度磷酸二辛酯的制备方法，本发明采用辛醇与水作为溶剂，加入磷酸混合辛酯与磷酸混合辛酯碱解所需理论量1.1～1.35倍的固体碱，经过高温碱解后，再经过两次酸化反应，得到含量与纯度高的磷酸二辛脂。本发明减少了固体碱的用量，不需要加入相转移催化剂，步骤简单，反应条件温和，能耗低，反应周期较短，得到的磷酸二辛酯的含量大于93％，纯度高。