Dielectric behaviors of PHBHHx–BaTiO3 multifunctional composite films

Multifunctional polymeric composites were investigated for potential use in high energy storage capacitors and tissue engineering. The polymeric composites were fabricated by employing biodegradable polyester, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), as the matrix. Ferroelectric BaTiO3 ceramic powders were added to the composites as fillers. The dielectric spectroscopy of the composites was measured over a wide frequency range (100–107 Hz) from −100 to 60 °C. The composition dependent dielectric behavior was modeled by a self-consistent effective medium theory. A percolation threshold of 0.367 was observed in the composites. The glass transition relaxation of the composite was also discussed by comparing the popular Vögel–Fulcher–Tammann law with a new glass model. The composites show attractive ferroelectricity and piezoelectricity for biomedical applications.