Thermoplastic polyurethane/rutile titanium dioxide composites tuned for hydrophobicity with effective reinforcement

High-performance thermoplastic polyurethane (TPU)/ rutile titanium dioxide (TiO₂) composites were prepared by melt-compounding method. TPU composites were investigated for their improved hydrophobicity, and free surface energy upon the addition of TiO₂. The hydrophobicity of TPU/TiO₂ composites at filler loading of 15 phr, increased up to 46% compared to that of the neat TPU. The decrease in free surface energy further confirmed the hydrophobic behavior of TPU/TiO₂ composites. Furthermore, hardness, abrasion resistance, tensile strength, and elongation at break were improved at lower filler loading of 2 phr and 5 phr. At T_max, thermal stability value of TPU also increased up to 407 ºC for 5 phr of TiO₂ however, the recorded value of thermal stability for neat TPU was only 334 °C. The residual content for TPU/TiO₂ composites also increased with the increase in the filler content. Due to such unique properties especially the hydrophobicity and abrasion resistance, these composites have potential applications in shoe sole industry.