Polyimides have excellent thermal resistance and mechanical properties, and attempts are being made to use them for different applications in a variety of advanced technologies. Interest in these materials is particularly high in areas related to electronics, where miniaturization, large-scale integration, and high-speed signal processing in semiconductor-based components are important technical issues. In order to satisfy these high expectations, stringent and highly varied requirements have been placed on the properties of polyimide materials, including, for example, high thermal resistance, high purity, high chemical resistance, high adhesion, high planarity, low dielectric constant, low thermal expansion, and, in some cases, high transparency and high refractivity. It is impossible for a single system to satisfy all of these requirements, so at present polyimides having different chain structures are used, according to the particular application [1, 2].