Preparation process of allyl alcohol polyether with low potassium and sodium content

A preparation process of an allyl alcohol polyether with a low potassium and sodium content, comprising the following steps:

• S1:
• reacting allyl alcohol with a mixture of epoxypropane and oxacyclopropane to prepare an allyl alcohol oligomer crude product with a molecular weight of 150-1500;
• S2:
• reducing the total content of potassium and sodium ions in the allyl alcohol oligomer crude product prepared in step S1 to 2 ppm or less through a cation exchange resin;
• and
• S3:
• reacting the allyl alcohol oligomer product treated in step S2 with the mixture of epoxypropane and oxacyclopropane to prepare allyl alcohol high-molecular-weight polyether with a molecular weight of 2000-5000, wherein
• the step S2 comprises:
• heating the prepared allyl alcohol oligomer crude product or a diluted solution obtained by diluting the prepared allyl alcohol oligomer crude product with a solvent to a temperature of 20-120° C., and then passing through the cation exchange resin under a protection of nitrogen under a pressure of 0.05-0.2 MPa, wherein a volume of the allyl alcohol oligomer crude product is 2-150 times that of the cation exchange resin, optionally removing the solvent if present;
• and
• the step S3 comprises:
• adding a DMC catalyst into the allyl alcohol oligomer product obtained after step S2, replacing nitrogen for three times and then heating to a temperature of 100-110° C. followed by dehydrating for 1-1.5 h, subsequently heating to 120-160° C., and then continuously adding the mixture of epoxypropane and oxacyclopropane under a pressure of ≤0.35 MPa to react until the pressure does not change any more;
• and
• in the step S3, a mass ratio of the epoxypropane to the oxacyclopropane is in a range of 1:25-100.