DFT Calculation of the Mechanism of the Acid-Catalyzed Aldol Condensation of a Lubricant Base Stock

Aldehyde condensation is a reaction step in the oxidization of lubricant base stock into high-molecular-weight products, forming sludge and paint film, which lead to failure lubricating oil. Calculations on basis density functional theory (DFT) were employed investigate mechanism acid-catalyzed aldol stock. Carbonyl compounds could be converted their resonant enol structures. However, activation energy process was relatively high, it difficult initiate. The existence acid obviously decrease from 269.17–287.82 kJ/mol 177.10–177.63 kJ/mol, significantly reduced difficulty initiating this reaction. carbocation formed by carbonyl further react with produce an intermediate product chain molecules grew longer. This not initiate, 65.10 kJ/mol. larger molecular weight containing β-hydroxy removing hydrogen proton it. barrier for 193.15 easy initiate