Molecular dynamics simulation of mechanical properties in polymer nanocomposites reinforced with hydrogen and fluorine-functionalized SWCNTs

Abstract

This study presents the first systematic molecular dynamics investigation of polyethylene (PE) and polypropylene (PP) nanocomposites reinforced with randomly functionalized single-walled carbon nanotubes (SWCNTs). Armchair (8,8) and zigzag (14,0) SWCNTs with nearly identical diameters (10 Å) were functionalized with hydrogen and fluorine atoms at 5–25% functionalization levels and incorporated into polymer matrices at 10% volume fraction. Representative volume elements (RVEs) were subjected to tensile loading simulations up to failure using Tersoff and Dreiding potentials to quantify Young’s modulus, maximum stress, failure strain, strain energy, and toughness. Results demonstrate that increasing functionalization consistently reduces mechanical properties across all systems, with Young’s modulus decreasing from range of 60–70 GPa to the range of 40–50 GPa and maximum stress declining from around 11 GPa. Zigzag SWCNTs generally outperformed armchair configurations in stiffness and strength, while armchair SWCNTs exhibited superior strain capacity. PE-based nanocomposites showed slightly better performance than PP-based systems for certain properties. Although CNT–polymer nanocomposites have been widely studied, a systematic comparison of randomly applied hydrogen and fluorine functionalization in both PE and PP matrices has not been conducted before. Comprehensive comparative analysis between functionalization types, polymer matrices, and nanotube chiralities provides essential design guidelines for optimizing nanocomposite performance in various applications. © The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2026.