Synergistic Effect of Micro- and Nano-Tio2 on Hydrophobic, Mechanical, and Electrical Properties of Hybrid Polyurethane Composites

One of the ways to improve the performance of ceramic insulators in polluted climates is to use polymer coatings reinforced with ceramic particles. This study compares the hydrophobic, mechanical, and electrical properties of solely filled polyurethane (PU) with nanoparticles and co-filled PU with nano- and microparticles. Stearic acid was used as an inexpensive and environmentally friendly surface modifier. FTIR analysis was conducted to ensure that hydrophilic titanium dioxide changed to hydrophobic. Coated polyurethane–TiO2 and their free films containing 1 wt% and 3 wt% titania were compared with each other and the pure PU. AFM analysis and topography FESEM images showed a higher surface roughness in micro-nanocomposites (hybrid) compared to the nanocomposite samples. The maximum contact angle belonged to the hybrid sample containing 0.5 wt% nanoparticles and 0.5 wt% microparticles. The contact angle increased from 73° to 95°. The mechanical strength improved by 40%, and the electrical resistivity of the resulting composite increased about 3 times with the introduction of modified titanium dioxide. This study indicated that the synergistic effect of titania micro- and nanoparticles could cause more enhancement in contact angle, tensile strength, elongation, and electrical resistivity.