Investigating the mechanical properties of high dielectric constant polyetherimide/(Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 composites

In this study (Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 (BSTZ) ceramic powder is mixed with polyetherimide (PEI) to form flexible PEI/BSTZ composites, and the effects that different BSTZ content has on the dielectric and mechanical properties of these composites are investigated. The dielectric constant increases from 2.52 to 20.28 as the BSTZ filler content increases from 0 wt% to 70 wt%. Logarithmic mixing rules can be used to predict and fit the dielectric constants of the PEI/BSTZ composites. Improvement in the composites’ tensile strength arises from the increase in interactions between neat PEI and BSTZ ceramic powder, and no separation of PEI and BSTZ ceramic powder occurs. Young’s modulus for the flexible PEI/BSTZ composites increases from 1.51 GPa to 2.38 GPa as the BSTZ filler content increases from 0 to 50 wt%. The elongation at break of the composites decreases with increasing BSTZ content, indicating that the composites become more brittle than neat PEI.