Synthesis of Succinic Acid Alkyl Half-Ester Derivatives with Improved Lubricity Characteristics

Abstract

A series of succinic acid alkyl half-esters were synthesized with higher than 97% yields by a one-step reaction of succinic anhydride with various fatty alcohols. The synthesized esters were soluble in 100N base oil at 1 wt %, and the lubricating properties of the esters in ultralow-sulfur diesel fuel were measured using a high-frequency reciprocating test rig and a four-ball wear machine. Wear scar diameter results showed that lubricity depended on the presence of a carboxylic acid group and that enhancements to lubricity depended strongly on the chain lengths of the alkyl group.