Machine learning-assisted design of the molecular structure of p-phenylenediamine antioxidants

Abstract

This study employed machine learning to predict the solubility parameter (δ) and bond dissociation energy (BDE) of antioxidant molecules, focusing on p-phenylenediamine derivatives with varying carbon chain lengths, side group positions, and functional groups (–CH₃, –OH, and –NH₂). The multilayer perceptron (MLP) model, enhanced by data augmentation and genetic algorithms, was developed to correlate the “molecular structure–descriptor–target parameter” relationship. The model achieved high prediction accuracy (coefficient of determination >0.86, relative percent difference >2.62). SHapley Additive exPlanations analysis revealed molecular polarity as the key factor influencing antioxidant performance. Molecules with –NH₂ side groups exhibited lower BDE values. A p-phenylenediamine derivative with ‘CH₃[CH₂]₁₃CH(NH₂)–’ connected to an aniline group showed optimal properties (Δδ = 0.02 (J cm⁻³)^0.5, BDE = 289.46 kJ mol⁻¹). Molecular simulations confirmed that the proposed antioxidant has excellent compatibility, anti-migration, and antioxidant activity in triglyceride oil. This study demonstrates the utility of MLP models for designing high-efficiency antioxidants for edible oils.