EFFECT OF SURFACE TEXTURES ON LONG-TERM MECHANICAL DURABILITY OF POLYMERS UNDER MOISTURE ENVIRONMENTS

Long-term mechanical durability of biomedical polymers is critical for ensuring the reliability and safety of medical devices such as implants and prostheses, which must withstand physiological conditions over extended periods without compromising performance. This study investigates the role of surface texturing in enhancing the mechanical durability of high-density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE) under prolonged moisture exposure. The results show that micro-textured polymer surfaces exhibit significant improvement in hydrophobicity compared to flat/smooth surfaces. This improvement in hydrophobicity delays moisture uptake in HDPE. In contrast, UHMWPE displays minimal differences in moisture absorption between textured and flat/smooth surfaces. Tensile testing under prolonged exposure to environmental conditions reveals that surface texturing significantly improves the retention of tensile properties in HDPE throughout prolonged exposure, while UHMWPE samples show similar mechanical behavior across all textures beyond the early exposure phase. The difference in moisture resistance and long-term mechanical behavior between HDPE and UHMWPE is attributed to their molecular structure differences. These results demonstrate the effectiveness of surface texturing in improving the long-term mechanical durability of polymers in moisture-rich environments.