Quantitative Structure Tribo Ability Relationship for Organic Compounds as Lubricant Base Oils Using CoMFA and CoMSIA

Abstract

The structures and the wear data of 47 different organic compounds as lubricant base oils were included in a comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA)–quantitative structure triboability relationship (QSTR) model. CoMFAand CoMSIAQSTR models illustrate good accuracy, robustness, and predictability, with the latter more accurate than the former. CoMFAQSTR with both steric and electrostatic fields: R2 = 0. 958, R2(LOO) = 0.958, and q2 = 0.625; with only a steric field: R2 = 0.987, R2(LOO) = 0.987, and q2 = 0.692. CoMSIAQSTR with a steric field: R2 = 0.924, R2(LOO) = 0.923, and q2 = 0.898, whereas CoMSIAQSTR with a hydrophobic field gave R2 = 0.985, R2(LOO) = 0.985, and q2 = 0.899. QSTR with CoMFA and CoMSIA shows a strong correlation to wear scar diameter scales (WDS), and builds statistical and graphical models that relate the wear properties of molecules to their structures.