Preparation method for monoalkyl maleate polyether

The invention relates to a preparation method for monoalkyl maleate polyether. The preparation method for the monoalkyl maleate polyether is characterized by comprising the following steps: 1, adding maleic anhydride, alkyl alcohol and catalyst to a high pressure kettle according to a ratio; after three times of vacuum-pumping and nitrogen displacement, adding epoxide to the high pressure kettle; stirring and heating the materials in the high pressure kettle to a temperature of 65-70 degrees centigrade; enabling the materials in the high pressure kettle to react with each other and release heat so that the temperature rises to 120 degrees centigrade; continuing the reaction till the pressure is kept invariable; 2, controlling the temperature of the high pressure kettle at 120-130 DEG C and the pressure of the high pressure kettle at 2-4 Kg; continuously dripping an epoxy compound to the high pressure kettle for reaction; continuing the reaction for 1-2 h; 3, carrying out vacuum-pumping the high pressure kettl