Analysis of the Effect of Nano‐Inclusion of Polyethylene Glycol Exfoliated Transition Metal Dichalcogenides in Epoxy Toughening

ABSTRACT Toughening of epoxy resin by exfoliated nanofillers is gaining interest, as toughened epoxies are considered potential candidates for advanced applications. Motivated by the role of polyvinylpyrrolidone (PVP) in exfoliating transition metal dichalcogenides (TMDs) and its notable impact on epoxy toughening, this work explores the potential of polyethylene glycol (PEG)–functionalized TMDs as effective toughening agents for epoxy composites. PEG‐exfoliated molybdenum disulfide (MoS ₂ ) and tungsten disulfide (WS ₂ ) were synthesized and used for epoxy toughening. The effect of PEG‐exfoliated MoS ₂ and WS ₂ in tuning the properties of epoxy resin is comprehensively presented. The impact of these TMDs is evident from the 422% and 558% improvement in stress intensity factor for PEG‐exfoliated MoS ₂ and WS ₂ , respectively, compared to neat epoxy. The improvement in both fracture toughness and tensile strength of PEG‐exfoliated WS ₂ is attributed to better exfoliation and enhanced compatibility with the epoxy matrix. While PEG‐based exfoliation of TMDs has been widely studied, its role in modifying the overall properties of epoxy composites has not been systematically investigated. This study offers a quantitative benchmarking framework that is novel and valuable for future material design and optimization.