Dielectric and mechanical properties of TiO2/polyimide composites with low dielectric constant

Abstract With the advent of 5G era, the high millimeter‐wave frequency band, poor signal penetration and large loss make 5G communication more dependent on low dielectric constant materials. Therefore, the research and development of low dielectric polymer materials has become a hot spot in recent years. With its good chemical corrosion resistance, thermal stability, high dispersion and high mobility, titanium dioxide (TiO 2 ) as a high function fine inorganic material is doped in polymer systems to improve the electrical properties of polymer composites. In recent years, a large number of studies have used spherical TiO 2 nanoparticles doped on the polymer matrix, however, there is almost no research on doping nanolinear TiO 2 nanoparticles on the polymer matrix. Here, TiO 2 nanowires were prepared by hydrothermal method, and the prepared TiO 2 nanowires were added to polyimide (PI). TiO 2 /PI monolayer and three‐layer composite films with good dielectric and mechanical properties were prepared by in‐situ polymerization. Fourier transform infrared spectoscopy, scanning electron microscopy and X‐ray diffraction were used to characterize the structure and test the properties of the composites. During the initiation process, the thermal initiation reaction of the composite membrane was completed. The composite film with good mechanical properties and excellent dielectric properties were obtained by adding titanium oxide nanowires, which can meet the requirements of its use in the field of microelectronic devices.