Obtention of higher refractive index and transparent polymeric nanocomposite systems with small amounts of fillers for lenses application

Abstract

The development of new materials for obtaining ophthalmic lenses is a subject of great interest due to the great necessity of corrective lenses uses. The application of the lenses based on polymeric material that guarantees greater lightness and less risk of breakage, ensuring greater comfort to users of glasses. The use of nanoparticles in polymer nanocomposites can generate different properties in the final material, mainly when used in hybrid systems in which synergistic effects can be produced. Thus, the present work aimed to evaluate the optical properties of systems with poly(methyl methacrylate) and oxide nanoparticles (silica, zinc, zirconium, and titanium). The systems were characterized in terms of their optical behaviors (refractive index, transmittance, and color change) and mechanical behaviors (nanoindentation, and tensile strength). The results showed that silica-based systems tended to have greater transparency but generate lower refractive indexes. Systems containing zirconia, titanium, and zinc have a higher refractive index and smaller transparency than systems containing silica. Besides, the use of zirconia and titanium increases the nano-hardness and elastic modulus. The results showed that the use of these nanoparticles in binary systems leads to obtaining materials with higher refractive index, greater transparency, and best mechanical behavior. The combination of the nanoparticles also led to a better dispersion, reducing the impact on the color system and improve transparency. In this way, the materials developed using small amounts of fillers and present highly promising for the development of thinner, more resistant to scratching due to high hardness and higher transparent lenses.