Acid-base chemistry in high-performance lubricating oils

We have used stopped-flow kinetic studies to conduct an investigation into the acid neutralization reaction between overbased detergent additives and aqueous acid dispersed as w/o microemulsion droplets. Water-soluble pH indi cators have been used to monitor the change in pH during the reaction. The acid neutralization rate was found to be dependent on the concentration of overbased additive, the temperature of the system, and the hydrocarbon chai n length of the solvent. The systems are of importance in relation to the m echanism of acid neutralization by engine lubricants.