Electrostrictive and piezoelectrical properties of chitosan-poly(3-hydroxybutyrate) blend films

Herein, we report the high apparent piezoelectric coefficient for chitosan-poly(3-hydroxybutyrate) (CS-PHB) blend films. The structure of chitosan-poly(3-hydroxybutyrate) (CS-PHB) blend films, exploiting characteristics such as dielectric, polarization, apparent piezoelectric properties, and their dependencies on the composition, were investigated. Based on the results of XRD, SEM, FTIR, PFM, and dielectric spectroscopy measurements, the structure of CS-PHB blend films has been proposed, which consists of spheric-like inclusion formed by precipitating isotactic-PHB interface layer, which consists of syndiotactic-PHB hydrogen bonding with CS, and CS matrix. The synergistic effects of piezoelectricity and electrostriction help explain the high value of the apparent piezoelectric coefficient (d₃₃) obtained in the blend film with 13 wt% of PHB (d₃₃ ≈ 200 pC/N). The investigated CS-PHB blend films are a good candidate for tissue engineering applications.