Fundamental perspectives on development of conductive blends based on quaternized polysulfone: Optical and dielectric response

Growing demands of miniaturization and high performance in a wide variety of applications, from biomedicine to electronics, have generated new solutions concerning the obtaining of multifunctional materials. In this context, a way to compensate the weaknesses of a conductive polymer assumes its use together with another polymer. Such of blend was prepared by embedding of cellulose acetate phthalate in the quaternized polysulfone matrix. By analyzing the transmission spectra of pure polymer films and their blends was obtained the transparency, an important parameter for optical performances. At the same time, the dependence of dielectric properties and conductivity on frequency of these blends was studied. The dielectric constants have low values for the studied blends, being dependent on the chemical characteristics of blends compounds, in relation with the charge transfer complex and free volume and, consequently, with packing of the polymer chains and of the polarizable groups per volume units. Two relaxation processes occuring in polymers blend, caused by low-amplitude non-cooperative motion of kinetic units in side groups and a low-temperature caused by the large-scale cooperative motion of kinetic units in the main polymer chain, have been revealed. Moreover, the electrical conductivity of studied blends can be explained in terms of band conduction mechanisms, through band gap representation. The outcomes highlight the importance of new polymer blends uses as good candidates for ionic exchange membranes in industrial applications.