Low Dielectric, Good Adhesive, and Flame-Retardant Aromatic Poly(ether)s with Phosphine Sulfide Groups

Low dielectric insulating materials with good adhesive properties and flame retardance are becoming increasingly important for achieving high-speed and low-loss communications in electronic devices. In this study, phosphine sulfide (P=S) group-containing aromatic poly(ether)s with low dielectric, good adhesive, and flame-retardant properties were developed. The poly(ether)s exhibited low dielectric constants (ε = 2.55–2.72) and low dielectric dissipation factors (tanδ = 0.0026–0.0045) at 10 GHz. From the discussion based on the DFT calculations, these low dielectric properties are probably due to the low polar nature of the P=S groups, resulting in low atomic and orientational polarization components. In addition, these polymers exhibited self-extinguishing behavior in the flame-retardant evaluation due to the presence of phosphorus atoms and good adhesion to a Cu substrate, which may be due to the coordination ability of the P=S groups. Such polymers are promising candidates for new insulating materials used in high-frequency electronic devices.