Tribological Performance and Reinforcement Mechanisms of CNT ‐Reinforced PCTFE Composites: Molecular Dynamics Simulation and Experimental

Tribological Properties of Silicon Carbide‐Reinforced Polytetrafluoroethylene/Epoxy Resin Composite Coatings: Molecular Dynamics Simulation and Experimental Validation

Wear‐induced failure of railway switch slide chairs remains a critical challenge, and conventional coating optimization still relies heavily on time‐consuming trial‐and‐error experiments. Therefore, molecular dynamics (MD) simulations combined with experimental investigations were employed to systematically investigate the effects of silicon carbide (SiC) content (0, 1, 3, 5, and 7 wt%) on the tribological properties of polytetrafluoroethylene/epoxy resin (PTFE/EP) composite coatings. Molecular models were constructed using Materials Studio, and friction behavior under room‐temperature dry sliding was simulated via shear displacement to obtain the coefficient of friction and wear rate, which were validated experimentally. Results show that increasing SiC content leads to a gradual increase in the coefficient of friction, while the wear rate exhibits a non‐monotonic trend, decreasing first and then increasing, with the optimum performance achieved at 5 wt% SiC (T5). The simulation and experimental results are in good agreement. Both indicate that T5 exhibits the lowest wear rate, corresponding to an MD‐derived wear parameter of 15.5% and an experimental wear rate of 0.21 × 10 −4  mm 3  N −1  m −1 . Wear morphology analysis reveals a transition from adhesive wear in the neat PTFE/EP coating to predominantly abrasive wear after SiC incorporation. These results confirm the reliability of the MD approach for designing PTFE/EP composite coatings.

Dispersion-informed structure–property relationships in carbon nanotube–reinforced polypropylene thermoplastic composites

Carbon nanotube (CNT)-reinforced polypropylene (PP) thermoplastic nanocomposites were systematically investigated to examine how CNT dispersion and CNT–matrix interfacial interactions influence the coupled mechanical, rheological, and electrical behavior of multifunctional thermoplastic composites under industrially relevant processing conditions. PP/CNT nanocomposites containing 0.1–5 wt% multi-walled carbon nanotubes (MWCNTs) were fabricated through twin-screw melt compounding followed by injection molding. The resulting composites were characterized using tensile and impact testing, oscillatory rheology, electrical resistivity measurements, scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR). Uniform CNT dispersion at low filler contents promoted efficient stress transfer and interconnected network formation, leading to simultaneous enhancements in stiffness and strength. An optimum CNT loading of 1 wt% was identified, at which tensile strength and Young’s modulus increased by approximately 27% and 33%, respectively, while maintaining acceptable ductility and processable melt rheology. Rheological measurements demonstrated enhanced melt elasticity, increased storage modulus, and partial stress recovery associated with CNT-induced viscoelastic networks. Electrical resistivity decreased progressively with CNT loading, indicating increasing development of CNT-mediated conductive pathways. However, excessive CNT loading resulted in pronounced agglomeration, reduced tensile performance, and increased brittleness. Combined SEM, AFM, and mechanical analyses showed that increasing CNT agglomeration at higher loadings coincided with reduced tensile reinforcement efficiency and greater mechanical heterogeneity. SEM and AFM observations further indicated that CNT dispersion state and CNT–matrix interfacial interactions play important roles in determining the multifunctional response of PP/CNT thermoplastic nanocomposites. Overall, the results provide a dispersion-informed understanding of the coupled mechanical, rheological, and electrical behavior of PP/CNT nanocomposites and identify a favorable formulation window within the investigated melt-processing conditions.

Fabrication and Comparative Study of Large‐Diameter Multi‐Walled Carbon Nanotubes Filled Chitosan, Epoxy, and Polypropylene Composites

This study presents a systematic comparative investigation of large‐diameter (100–110 nm) multi‐walled carbon nanotube (MWCNT) reinforced composites utilizing three structurally distinct polymer matrices: chitosan (CS), epoxy (EP), and polypropylene (PP). Synthesized via aerosol‐assisted chemical vapor deposition, the MWCNTs were incorporated at concentrations ranging from 0.5 to 3 wt.%. The composite properties were evaluated through a comprehensive suite of analytical techniques, including SEM for morphology, FTIR and Raman spectroscopy for structural/chemical characterization, thermogravimetric analysis for thermal stability, laser flash analysis for thermal conductivity, and detailed DC/AC electrical characterization to assess charge transport dynamics. Experimental results demonstrate that the percolation threshold lies at approximately 1.0 wt.% for the EP and PP systems, while the CS‐based composite exhibits enhanced charge transport at this concentration. At 3 wt.% loading, all composites demonstrate ohmic, quasi‐metallic behavior. While all composites achieve a robust percolative network at 3 wt.% filler loading, the AC electrical characterization highlights distinct matrix‐dependent charge transport dynamics. These findings underscore the critical role of polymer‐filler interfacial interactions in governing functionality, positioning the MWCNT/CS composite as a promising candidate for eco‐friendly biomedical interfaces and advanced flexible electronics.

Tribological Characteristics of CNT/Graphene Reinforced PLA- Based Polymer Composites Fabricated via FDM Process

Creep behavior and dynamic mechanical performance of ball-milled poly(ether-ketone)/MWCNT nanocomposites

Mechanical Properties of Natural Fibre-Reinforced Polymer Composites with Carbon Nanofillers: Experimental and Mesoscale Modelling

Incorporating carbon nanotubes (CNTs) or graphene nanoplatelets (GNPs) into thermoplastic composites enhances electrical and thermal conductivity, as well as fire resistance, but may impair mechanical performance. To address this challenge and develop multifunctional yet mechanically robust materials, Kenaf fibre-reinforced high-density polyethylene (HDPE) composites have been developed using a microwave-assisted compression moulding technique, incorporating 5% weight fraction of CNTs and GNPs. Addition of nanofillers resulted in up to a 30% reduction in energy consumption and a 12.5% reduction in processing time. The reinforcing effect of CNTs due to their high strength and aspect ratio enhanced bonding and mechanical performance, with tensile strength increasing by 11% and hardness by 17%. To complement the experimental findings and support future design optimisation, this study also introduces a novel, simplified two-step finite element method-based mesoscale model for predicting composite’s anisotropic properties. Employment of the cohesive zone model accounts for imperfect bonding between CNTs and the HDPE matrix. Simulations reveal that at a maximum fibre content of 29%, the in-plane elastic modulus is 3.6 times that of the pure matrix. This study demonstrates the potential of these nanofillers reinforced natural fibre composites for lightweight aerospace and automotive applications, offering enhanced performance while contributing to environmental sustainability.