Abstract: By choosing the right feeding method, polyether polyols with low unsaturation and narrow molecular weight distribution can be prepared by using KOH as catalyst to catalyze the polymerization of epoxy monomer with alcohol or phenol.The amount of catalyst used and the reaction temperature affect the yield and the quality of the product to a great extent, so controlling the appropriate amount of catalyst and reaction temperature is the key to the preparation of polyether polyols.When different phenols and alcohols are used as starting agents, the reactivity decreases gradually with the increase of chain length, and more catalysts and longer reaction time are needed to achieve high reaction yield.Compared with propylene oxide, the reactivity of epoxy butane decreased due to the increase of steric hindrance, and more catalysts were needed to prepare polyether products with designed molecular weight.When epoxy propane and epoxy butane are used as epoxy monomers at the same time, copolymerization of polyether products with variable structure can be prepared by adjusting the feed ratio of the two.The polyether product prepared by this method has low bromine value and molecular weight distribution below 1.10, and after post-treatment, the water content of the product can be kept below 0.2%, the potassium ion content is below 1 μg/g, and the product quality is high.

Key words: polyether polyols, potassium hydroxide, propylene oxide, butane oxide