The Research Of BaTiO₃/PMMA Piezoelectric Composite And Its Polarization

After the loss of teeth, resorption of residual ridge(RRR) will be going on. This may result in the osseous loss and the shape change of the alveolar ridge, which influences the repair of denture, mastication and so on. In prosthodontics, it becomes a problem to be urgently solved. Considering the piezoelectricity of the bone, we try making denture base with BaTiO₃/PMMA piezoelectric composite. This denture base is expected to produce low electricity when masticating. The low electricity can stabilize resorption of residual ridge or promote the growth of alveolar ridge. In our experiments, BaTiO₃/PMMA piezoelectric composite was made and poled.Firstly, samples were prepared with BaTiO₃/PMMA powder and methyl methylacrylate(MMA) by the technique of heat treatment which is usually used in the facture procedure of removable denture. Ni-Cr alloy was then plated on samples by evaporation in the vacuum. The samples were poled under different poling voltage and different poling time. And then, their piezoelectric constants were measured and analyzed. We got the following results.1. BaTiO₃/PMMA piezoelectric composite is made successfully. TheBaTiO3 particles are evenly dispersed in the PMMA.2. The piezoelectric constant of BaTiO3/PMMA piezoelectric composite increases with increase of the poling voltage. However, the increase is statistically insignificant when the poling voltage exceeds 9kv. In the poling voltage range from 0 to 9kv, the relation between the piezoelectric constant and the poling voltage is linear, which may be described with the regression equation: y=0.06+0.59x( X means the poling voltage and y means the piezoelectric constant.).3. The piezoelectric constant of BaTiOa/PMMA piezoelectric composite increases with increase of the poling time. But, the increase is insignificant in statistics when the poling time exceeds 25 minutes. In the poling time range from 0 to 35 minutes, the relation between the piezoelectric constant and the poling time may be described with the regression equation: y=0.156+0.322x-0.005x2 (X represents the poling voltage and y means the piezoelectric constant.). This equation shows that the relation is a part of the parabola.From the above, we can get the conclusions. BaTiCb/PMMA piezoelectric composite can be gotten by the technique of heat treatment. Its piezoelectricity is dependent on the poling voltage or the poling time. The different piezoelectricity can be gotten by regulation of the poling voltage or the poling time.