TiO2 filled polytetrafluoroethylene (PTFE) composite were fabricated for microwave circuit applications. PTFE/TiO2 composites were prepared by cold pressing and hot treating. The particle size of TiO2 varied from 5 μ...TiO2 filled polytetrafluoroethylene (PTFE) composite were fabricated for microwave circuit applications. PTFE/TiO2 composites were prepared by cold pressing and hot treating. The particle size of TiO2 varied from 5 μm to 11 μm.TiO2 powders with different sizes were prepared by the solid state ceramic route. The effects of TiO2 particle size on the microstructure, density, moisture absorption, thermal conductivity and microwave dielectric properties of PTFE/TiO2 composites were investigated. The density showed an increasing trend as the TiO2 particle size increased, while the dielectric loss (tanδ) and moisture absorption decreased with the increase of TiO2 particle size. The dielectric constant (εr) and thermal conductivity (λ) decreased up to D50 = 6.5 μm and then sharply increased. Good properties with values of εr = 6.8, tanδ = 0.0012 and λ = 0.533 W?m?1?K?1 were obtained in PTFE/TiO2 composites when the particle size of TiO2 was 11 μm.展开更多
In this paper, a detailed study was carried out on the PTFE reinforced with TiO2 and CaTiO3. The filler content of ceramic powder was a fixed value of 61 wt% and the content of CaTiO3 in PTFE matrix varied from 0 wt% ...In this paper, a detailed study was carried out on the PTFE reinforced with TiO2 and CaTiO3. The filler content of ceramic powder was a fixed value of 61 wt% and the content of CaTiO3 in PTFE matrix varied from 0 wt% to 16 wt% with a step size of 4 wt%. The effects of CaTiO3 loading on the density, moisture absorption, thermal expansion, microstructure and microwave dielectric properties were investigated. As CaTiO3 loading content increased from 0 wt% to 16 wt%, the thermal expansion initially displayed a sharp increase, and showed a slight enhancement when the content of CaTiO3 exceeded 12 wt%. The density experienced a continuous decrease with the addition of CaTiO3. The moisture absorption displayed a steady increase with the increasing CaTiO3 loading amount. The changing of dielectric constant (εr) and loss tangent (tanδ) were similar to that of the moisture absorption in a manner. Good dielectric properties with values of εr = 11.60, tanδ = 0.002 were obtained in the PTFE matrix with 16 wt% CaTiO3 and 45 wt% TiO2.展开更多
文摘TiO2 filled polytetrafluoroethylene (PTFE) composite were fabricated for microwave circuit applications. PTFE/TiO2 composites were prepared by cold pressing and hot treating. The particle size of TiO2 varied from 5 μm to 11 μm.TiO2 powders with different sizes were prepared by the solid state ceramic route. The effects of TiO2 particle size on the microstructure, density, moisture absorption, thermal conductivity and microwave dielectric properties of PTFE/TiO2 composites were investigated. The density showed an increasing trend as the TiO2 particle size increased, while the dielectric loss (tanδ) and moisture absorption decreased with the increase of TiO2 particle size. The dielectric constant (εr) and thermal conductivity (λ) decreased up to D50 = 6.5 μm and then sharply increased. Good properties with values of εr = 6.8, tanδ = 0.0012 and λ = 0.533 W?m?1?K?1 were obtained in PTFE/TiO2 composites when the particle size of TiO2 was 11 μm.
文摘In this paper, a detailed study was carried out on the PTFE reinforced with TiO2 and CaTiO3. The filler content of ceramic powder was a fixed value of 61 wt% and the content of CaTiO3 in PTFE matrix varied from 0 wt% to 16 wt% with a step size of 4 wt%. The effects of CaTiO3 loading on the density, moisture absorption, thermal expansion, microstructure and microwave dielectric properties were investigated. As CaTiO3 loading content increased from 0 wt% to 16 wt%, the thermal expansion initially displayed a sharp increase, and showed a slight enhancement when the content of CaTiO3 exceeded 12 wt%. The density experienced a continuous decrease with the addition of CaTiO3. The moisture absorption displayed a steady increase with the increasing CaTiO3 loading amount. The changing of dielectric constant (εr) and loss tangent (tanδ) were similar to that of the moisture absorption in a manner. Good dielectric properties with values of εr = 11.60, tanδ = 0.002 were obtained in the PTFE matrix with 16 wt% CaTiO3 and 45 wt% TiO2.
