Optical Properties of Rosin/PMMA Nanocomposites

There are many organic molecules having functional properties potentially useful for technological applications in otics, optoelectronics, sensing, etc. However, such organic molecules are frequently thermally and/or photochemically unstable. The dissolution of such molecules un an adequate type of polymer allows at the same time the preparation of a functional materials and the stabilization of the organic molecules. Such stabilization results from the capability of the polymer matrix to absorb photon thermally-induced and to prevent rearrangements. As an example, the rosin, also called colophony is the main component of a very abundant natural substance present in the resin obtained from pines and some other plants. This type of organic compound has interesting fluorescence properties that can be enhanced by mild thermal treatment. However, excessive annealing could degrade the molecule, thus loading to the loss of this useful physical property. Since rosin is highly soluble in organic media like the common thermoplastic polymer it is possible to achieve its stabilization by dissolution in polymers. Here, rosin has been dissolved in poly(methylmethacrilate), which is an optical characterized by high transparency in the visible region. The ability of the polymer-embedding process in the stabilization of this molecules has been verified by thermal analysis (TGA, DSC). In addition, the optical properties of the PMMA-Rosin have been compared with the pure rosin to assess the possibility to exploit these materials in the optical field.