Method for preparing pentaerythritol tetrakis(3-dodecylthiopropionate) antioxidant

The invention discloses a method for preparing a pentaerythritol tetrakis(3-dodecylthiopropionate) antioxidant. The preparation method comprises the following steps: 1) mixing dodecene with an azo compound, heating the obtained mixture to 60-85 DEG C, adding 3-mercaptopropionic acid, and performing stirring and reacting; 2) heating the obtained reaction product to 100-120 DEG C, adding a pentaerythritol and acidic catalyst mixed solution, and performing mixing and reacting; and 3) purifying and drying the obtained reaction solid product to obtain the pentaerythritol tetrakis(3-dodecylthiopropionate). The medium acidic catalyst used in the preparation method has the advantages of high reaction activity, good dispersion and low price. The preparation method has the advantages of mild reaction process, no device corrosion, simplicity in operation, high selectivity of the catalyst to the product, and light color of the product. A solvent used in an esterification reaction is a mixed solvent, and has an excellent