Processing of PVDF/Nb5+ and Sr2+-Doped PZT Composites for Applications in Advanced Dielectric Insulation: Effect of Ceramic Loading on Structure, Mechanical Properties, Electrical Properties, and Thermal Aging Behavior.

In this study, four types of materials suitable for use as special insulation were produced. Polyvinylidene fluoride (PVDF) served as the polymer matrix, while PZT powders (a Pb(Zr0.52Ti0.48)O3 system doped with Nb5+ and Sr2+) were used as the filler material; the method for producing these powders is also described. The mass concentrations, expressed as PVDF/PZT ratios, were 100/0, 95/5, 90/10, and 80/20. Characterization analyses and tests were conducted to verify the materials' suitability as insulators. Specifically, the materials underwent structural (SEM and FTIR), chemical (EDS), mechanical, and dielectric testing (measuring tan δ, εr, ρ, and Estr). Additionally, resistance to degradation at the maximum operating temperature was evaluated through thermal resistance tests at 150 °C. Finally, the remaining service life prior to complete material degradation-and the consequent need for replacement-was determined. All characterization tests indicated that the composite material with a 5% PZT powder concentration-which exhibits the best structural, mechanical, dielectric, and thermal properties-represents the optimal composite variant for insulation applications. Potential applications for these materials include coatings for electric field grading and voltage control, as well as insulation for high-voltage transients and impulses.