Reinforced properties of ethylene-propylene-diene monomer composites by vinyltrimethoxysiloxane functionalised barium titanate

In this study, non-conductive ethylene-propylene-diene monomer (EPDM)/barium titanate (BaTiO₃) composites with high dielectric constant and low dielectric loss are prepared. Fourier transform infrared (FT-IR) spectra show the chemical adherence of vinyltrimethoxysiloxane oligomer (SG-Si6490) to the surface of BaTiO₃ particles. Functionalised BaTiO₃ particles have better compatibility with EPDM matrix and promote the cure properties of EPDM composites. It is found that when the content of BaTiO₃ increases to 40 vol.-%, the resistivity, rheological, dielectric and mechanical properties of EPDM/BaTiO₃ composites change drastically. The dielectric constant of EPDM with 50 vol.-% BaTiO₃ at 10 MHz is 15, which is 7.5 times higher than that of EPDM control. Meanwhile, the volume resistivity results show EPDM with 50 vol.-% BaTiO₃ is still non-conductive. As for mechanical properties, the tensile and tear strength of EPDM control increase from 1.45 MPa and 8.73 kN m^-1 to 10.02 MPa (about seven times higher) and 24.65 kN m^-1 (about three times higher), respectively.