Triton X‐100 Surfactant Effects on Friction and Wear of Short Carbon Fiber–Epoxy Composite

ABSTRACT Interfacial debonding accelerates wear in short carbon fiber–epoxy composites (V _f = 40 ± 2). Triton X‐100 surfactant (1, 2, and 3 wt.%) was applied to modulate friction and wear performance, with modified composites designated as CE‐1S, CE‐2S, and CE‐3S. Pin‐on‐disc tests (ASTM G99) against EN31 steel (58–60 HRC) were conducted at 15–25 N and 1.05–1.57 m/s. Gravimetric analysis recorded 0.85% mass gain at 1 wt.% concentration, consistent with near‐saturation adsorption behavior. At this optimal concentration (CE‐1S), steady‐state COF decreased from 0.45 to 0.29, representing a 35.56% reduction relative to the untreated baseline ( p < 0.05). The specific wear rate for CE‐1S decreased by 27.4% (to 8.68 × 10 ⁻⁵ mm ³ /N m) at 1.57 m/s and by 64.3% ( p = 0.0012) at 1.05 m/s. Surfactant concentrations above 1 wt.% were associated with excess deposition that progressively degraded tribological performance. SEM observations were consistent with a reduction in fiber pull‐out from 64 ± 9 to 22 ± 4 m, while void fraction dropped from 6.3% to 2.1%. These results suggest that 1 wt.% surfactant enhances interfacial adhesion and wear resistance.