Dielectric relaxation studies of low thermal expansion polymer composites

The results of temperature-dependent dielectric and rheological measurements are reported on polymer-ceramic composite films, poly(methyl methacrylate) (PMMA) : lead titanate (PbTiO3). Analyses of relaxational processes of the PMMA host matrix have been investigated using temperature-dependent dielectric and rheological measurements. It is found that the α-relaxation is more significantly affected by the addition of filler in comparison to β-relaxation. The composite films are found to have much lower dielectric constants in comparison to the pure ceramic material. Suitable models have been used to explain the observed dielectric constant of the composite films. Using rheological measurements, occurrence of reinforcement in these composite films due to the addition of ceramic filler has also been observed and the results are discussed in the article. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013