Research on dielectric and microwave absorbing properties of TiO2/TiB2/Thermoplastic polyurethanes (TPU) composite materials

Abstract TiO 2 /TiB 2 materials are prepared by the carbothermal method and high-temperature calcination. Further, the phase composition, microstructure, dielectric and electromagnetic (EM) wave absorption characteristics are investigated. The results display that the product is composed of TiO 2 , TiB 2 and impurity phases. The complex permittivity increases at elevated TiO 2 /TiB 2 loading and slowly decreases with rising frequency in 2-18 GHz. When the TiO 2 /TiB 2 content is 45 wt%, the minimum reflection loss ( RL min ) reaches -43.12 dB at 11.68 GHz with a thickness of 1.9 mm. The effective absorption band (EAB, RL <-10 dB) can reach 3.68 GHz at 2.3 mm as the TiO 2 /TiB 2 content is 30 wt%. The enhanced EM wave absorption owes to the strong polarization loss and high conductivity loss. It goes without saying that TiO 2 /TiB 2 materials can acquire important breakthroughs in the development of novel EM wave absorbers with outstanding absorption loss, wider EAB and smaller thicknesses.