PPDO purification method

The invention discloses a method for purifying PPDO. According to the method, a dihydroxy alcohol alkyl ether or dihydroxy alcohol aryl ether solvent is adopted for solvent extraction and purification of PPDO. According to the purification method, by adjusting the type, the extraction temperature and the time of the extraction solvent adopted in the PPDO purification process and the mass ratio of the PPDO crude product to the extraction solvent, the content of the purified PDO monomer can reach 1.0% or below, the temperature used in the purification method is low, and great degradation of PPDO is avoided; the purification method has no limitation on molecular weight or viscosity, and can be suitable for PPDO with different molecular weights and viscosities; the PPDO is subjected to solvent extraction and purification by the dihydroxy alcohol alkyl ether or dihydroxy alcohol aryl ether solvent, so that the extraction time is greatly shortened, and the purification efficiency is improved. 本发明公开了一种PPDO的纯化方法，其采用二