New Directions in Corrosion Inhibitor Design

There have been two main approaches to construct Structure-Property Relationships for use in the design of better organic corrosion inhibitors.  In one approach, additivity models are used to piecemeal select functional groups to build the corrosion inhibitor.  This approach makes the assumption that each functional group in the corrosion inhibitor molecule contributes a unique, independent and additive increment to the corrosion inhibition efficiency.  In the second approach, a range of ‘descriptors’ calculated from the molecular structure (these can be molecular electrostatic potentials, quantum mechanical energies, connectivity indices, etc) are regressed against the corrosion inhibitor efficiencies.  Both of these approaches have drawbacks.  Models using the functional group approach cannot predict the performance of new materials that have functional groups in the database.  The second approach suffers from chance correlations when large numbers of inhibitors are regressed against the corrosion performance.  We will present the results of our recent work that provides a Quantum Mechanical foundation under the functional group approach allowing the excellent prediction of corrosion inhibitor performance with just a few variables.