Thermoplastic polyurethane elastomer induced shear piezoelectric coefficient enhancement in bismuth sodium titanate – PVDF composite films

A series of ester‐based thermoplastic polyurethane elastomer (TPU) and bismuth sodium titanate polycrystalline oxide (Bi0.5Na0.5TiO3, BNT) co‐blended poly (vinylidene fluoride) (PVDF) composite films were prepared. Mechanical test confirms the optimum BNT blending content (25 wt%) and further reveals a linear growth of tensile elongation by increasing TPU content. Microstructure modifications including strengthened hydrogen bond and valence band edge elevation are evidenced to be highly correlated to the dielectric and piezoelectric properties. Significant enhancement (7–13 times) in face shear piezoelectric coefficient (d36) is achieved by adjusting the blending content of TPU. Cross‐section image presents a featuring multilayer structure with improved dispersity of BNT particle under a transverse tensile force which effectively increases the interfacial contact area between BNT and polymer blends. This work reveals the significance of band structure modification and anisotropic texture construction on influencing the transfer of piezoelectric charge in TPU blended BNT‐PVDF composite film.