Study on the Effect of Porosity on the Dielectric Characteristics of Polypropylene/Cenosphere Composites

A new, cost-effective porous polymer composite was developed by reinforcing polypropylene (PP) with cenosphere particles. This study investigates how the composite’s dielectric properties are affected by their porosity. Dielectric constant (ε′) measurements were taken over a range of frequencies at room temperature. A theoretical model was developed to explain the electrical conductivity of the porous PP/cenosphere composites. The study thoroughly examined how the inclusion of cenosphere particles influenced key electrical parameters, including dielectric constant, dissipation factor (tanδ), DC (direct current) conductivity, and AC (alternating current) conductivity. The results revealed that increasing the cenosphere content caused a decrease in the dielectric constant, while the dissipation factor increased. The developed porous PP/cenosphere composite exhibits a unique balance of low dielectric constant, lightweight structure making it suitable for several practical applications. Its low dielectric constant and reduced DC conductivity make it an excellent candidate for electronic packaging, insulating layers, and high-frequency components, where minimal energy loss and signal interference are required. The lightweight nature of the cenosphere-reinforced structure also suggests potential use in aerospace and automotive industries for lightweight insulation panels or structural components. Furthermore, its cost-effectiveness and tunable porosity could enable applications in microwave substrates, radar-absorbing materials, and energy-efficient building materials where dielectric control and weight reduction are critical. Additionally, DC conductivity was found to decline with higher cenosphere concentrations. The theoretical model was in good agreement with the experimental data.