Preparation method of allyl-terminated alkyl polyether

The invention belongs to the technical field of polyether synthesis, and discloses a preparation method of allyl-terminated alkyl polyether. The preparation method comprises the following steps: mixing alkyl polyether with an alkoxide reagent, and reacting at 100-150 DEG C to prepare an intermediate polyether salt; mixing an end-capping reagent with allyl methyl ether, then adding the intermediate polyether salt into the mixture, and carrying out etherification reaction to prepare a crude product; and adding acid into the crude product for neutralization, then adding ethanol, and vacuumizing to remove low-boiling-point substances, thereby obtaining the allyl-terminated alkyl polyether. According to the preparation method provided by the invention, alkyl polyether is used as a raw material to carry out alkoxide reaction, and the reaction temperature is controlled; then introducing alkoxide polyether into an end-capping reagent and a solvent in a trans-dropwise adding manner to carry out etherification reaction