BaTiO₃/IPNs composites: Preparation and correlation between dielectric characters and damping performance

BaTiO₃ / Interpenetrating Polymer Networks (IPNs) composites were prepared by combination of BaTiO₃ nanocrystal in tetragonal system and polyurethane(PU) / unsaturated polyester (UP) interpenetrating polymer networks (IPNs). The tetragonal nanocrystalline BaTiO₃ was obtained by hydrothermal process and calcination at 1 200°C. The prepared materials were polarized with high voltage and small current, and protected by silicon oil. The morphology of BaTiO₃ / IPNs and the effect of combination of BaTiO₃ on the damping behavior of IPNs were studied. The relationship between damping performance and dielectric charater was also discussed in terms of dielectric constant and dielectric loss measured. The results show that the areas under loss modulus (E″) and the values of loss factors (tanδ) were both increased by combination of BaTiO₃ into IPNs system. The maximum value of E′ increased above 100 MPa compared with pure IPNs and the extent increased more remarkably after polarizing process. The main and shoulder peak of tanδ curves both moved toward higher temperature ranges, and the temperature ranges of tanδ>0.3 was higher than 100°C. Moreover, through polarizing process, the composites exhibited synergistic action caused by elastomeric damping, interfacial abrasive damping and piezoelectric damping mechanisms. The relationship study of damping property and dielectric characters showed that the temperature ranges exhibited excellent consistency of maximum dielectric loss and modulus with damping loss factor.