Addition of microcrystalline cellulose to an alkyd resin/titanium dioxide film: effect on dielectric properties.

In this study, various composite films were prepared by varying the amounts of long-oil Alkyd Resin (AR), Titanium Dioxide (TiO) and Microcrystalline Cellulose (MCC). The effects of each component, TiO and MCC, on the properties and microstructure of the dry film were determined by examining images obtained by scanning electron microscopy (SEM) and studying the evolution of dielectric properties, the dielectric constant and the loss factor, against frequency at room temperature. Results showed that the introduction of the TiO/MCC powder with a weight ratio larger than 1 and a volumetric pigment concentration (VPC) less than 50% allowed a better dispersion of the particles and fitted well the Linchtencker logarithmic mixing law and the Maxwell-Garnett theory. Finally, a marked improvement of the dielectric constant with respect to those of pure alkyd resin and AR/TiO composites was observed.