Preparation method for polyester polyol by grease restructuring

The invention discloses a preparation method for polyester polyol by grease restructuring, comprising the following steps: carrying out a basic hydrolysis on grease raw materials to prepare aliphatic acid and glycerin; weighing to take certain mass proportion of aliphatic acid, acetate, hydrogen peroxide (30%) and a catalyst, wherein m aliphatic acid: m acetate : m hydrogen peroxide : m sulfuric acid = 100:0-50:40-150:1-5, and adding the aliphatic acid, acetate and the catalyst into a reactor simultaneously; adding the hydrogen peroxide dropwisely for 1 hour to 2 hours at a temperature of 40 DEG C, standing the mixture for reaction for 2 to 4 hours at a temperature of 60 DEG C, and carrying our a ring opening hydrolysis for 1 hour to 2 hours in backflow state; carrying out phase splittingon the oxidized product, adding glycerin and an esterification catalyst into the organic phase, and carrying out esterification for 1 hour to 2 hours at a temperature of 180 DEG C under the conditionof reduced pressure (5-10 Kpa). Therefore, aliphatic acid polyester polyol with an acid value of 1 to 10 mg KOH/g and a hydroxyl value of 280 to 410 mg KOH/g is obtained.