Ester lubricating base oil with dumbbell-type structure and preparation method thereof

The invention relates to an ester lubricating base oil with a dumbbell-type structure and a preparation method thereof. The preparation method of the base oil comprises the following steps: firstly, synthesizing a dumbbell-type molecular skeleton by using aliphatic hydroxyl alcohol and dicarboxylic acid, and then esterifying the hydroxide radical on the molecular skeleton by using monocarboxylic acid so as to form an esterification product with a dumbbell-type structure; or firstly, synthesizing a single hydroxy polyolester by using the aliphatic polyhydroxy alcohol and the monocarboxylic acid, and then esterifying the single hydroxy polyolester and the dicarboxylic acid to synthesize the esterification product with a dumbbell-type structure. The method provided by the invention is used for obtaining the lubricating base oil with the dumbbell-type structure, and the base oil is provided with a dumbbell-type structure which is characterized in that the two ends of the structure are provided with highly branched chains, the middle of the structure is in direct connection, and the two ends are larger and the middle is smaller. The esters have the advantages of low pour point, high viscosity indexes, high flashing point and the like.