UHMWPE based composites with CNT fillers: Surface, mechanical and electrical aspects

This study presents a comprehensive investigation into the effects of carbon nanotube (CNT) incorporation on the surface, mechanical, and electrical properties of ultra-high molecular weight polyethylene (UHMWPE) composites, with particular emphasis on surface behavior-an often overlooked yet critical factor for sensor and interface-related applications. UHMWPE specimens were reinforced with varying CNT concentrations (0-2 wt %) and processed under controlled molding pressures and temperatures. Surface analysis using atomic force microscopy (AFM) revealed that CNT addition increased surface roughness, peaking at 113 nm for 2 % CNT loading, while contact angle measurements showed enhanced hydrophobicity up to 0.5 % CNT, beyond which hydrophilicity emerged due to filler agglomeration. The study also demonstrates that both molding pressure and temperature modulate surface properties, influencing roughness and wettability. Mechanically, CNT-reinforced composites exhibited substantial improvements in hardness (up to 5.51 GPa) and elastic modulus (up to 32.58 GPa), with molding pressure further enhancing these effects and elevated temperatures slightly reducing them. Electrically, CNT addition significantly decreased resistance, and higher molding pressures contributed to further conductivity gains, whereas temperature showed minimal impact. The novelty of this work lies in its integrated evaluation of surface, mechanical, and electrical characteristics, offering valuable insights into the functional tunability of CNT/UHMWPE composites for advanced engineering and sensing applications.