Abstract

Surface-modified hexagonal zinc oxide (ZnO) prisms were incorporated into commercial polyurethane (PU) coating. Dip-coated PU/ZnO composite films on polypropylene sheets exhibited a broad dip in ultraviolet (UV) transmittance corresponding to the ZnO band gap. Compared to 5 and 10 wt% loading, optical properties of PU composites were significantly modified by 20 wt% ZnO fillers in terms of the blue shift and splitting of UV peaks with substantially increased absorption. The morphology effect is demonstrated by replacing the hexagonal ZnO with sword-like ZnO. The sword-like ZnO gave rise to a lower UV absorption and the two slope characteristic in small angle X-ray scattering spectrum corresponding to the thin parts at tapered ends. The proposed procedure and materials used in this work are appropriate for economic large-scale production of composites.