Polyurethane nanocomposite films containing nano-cerium oxide as UV absorber. Part 1. Static and dynamic light scattering, small angle neutron scattering and optical studies

The present work reports the influence of nano-cerium oxide particles on UV resistance of a polyurethane lacquer. Particles were initially stabilized in 3-phosphonopropyl based stabilizer and dispersed in a polyacrylate resin, followed by mixing with polyisocayanate hardener to obtain nanocomposite films. Static and dynamic light scattering and small angle neutron scattering techniques were employed to study the stabilization of particles embedded in nanocomposites. It was shown that a monolayer of stabilizer was grafted at the surface of nano-cerium oxide out of which uniformly distributed mono-disperse particles in the films were prepared. Films were then subjected to 700 h of accelerated artificial weathering. Their optical performances were then accessed by UV–vis spectroscopy. Clear coats containing nano-ceria showed less deterioration in UV exposure test compared to the blank polyurethane film. Samples loaded with 1.44% (w/w) of nano-ceria absorbed 92.5% of incident UV light in UV-B region and 67% of UV light in UV-A region. However, after 700 h exposure to UV radiation, films could absorb 80% of UV-B and 50% of UV-A, showing the brilliant efficacy of this nanoparticle to act as UV absorber.