Polyester polyol is an important raw material for synthesizing polyurethane. It plays the role of a flexible soft segment in polyurethane synthesis, while isocyanate and small molecule chain extender constitute the hard segment of polyurethane. Since Chemicalbook polyester polyol affects the soft segment polarity and soft and hard aggregation structure of polyurethane elastomer molecules, the type, structure, number average molecular weight, etc. of polyester polyol have a great influence on the performance of polyurethane.