DFT-based investigation of polymer components for concrete impregnation: Electronic and structural insights

Abstract

This study presents a systematic density functional theory (DFT) investigation of the structural, electronic, and vibrational properties of polymer components used in concrete impregnation, namely styrene, divinyl benzene, and benzoyl peroxide. The molecular geometries of monomers and their oligomeric structures were optimized, and their electronic descriptors were analyzed to provide insights into stability and reactivity. The calculated HOMO–LUMO energy gaps indicated semiconducting behavior for the monomers, while a significant band gap reduction was observed with increasing polymer chain length, suggesting enhanced charge-transfer ability and optical activity during polymerization. Vibrational frequency analysis confirmed the characteristic modes of functional groups responsible for polymerization. In addition, global reactivity descriptors such as hardness, softness, and electrophilicity were evaluated to elucidate the trends associated with molecular growth. The findings highlight the strong correlation between chain length and electronic stability, and provide predictive insights into the performance of polymer–concrete composites at the molecular level. This theoretical framework complements experimental studies and may guide the design of more durable polymer-modified concrete systems.