Effect of preparation conditions on the dielectric properties of lightly cross-linked poly(sodium methacrylate)

The dielectric properties of dried gels based on poly(sodium methacrylate) were studied in a wide range of frequencies (20 Hz-20 kHz) and temperatures (20-80 degrees C). The corresponding hydrogels were synthesized in solutio n at varying monomer concentrations (20, 30 and 40%). The dried gels exhibi t sufficiently high dielectric constants (from 100 to 800), which increase as the synthesis is performed with the increasing initial concentration of the monomer. High values of the dielectric constant are explained by the pr esence of residual water in the system. The fraction and properties of the residual water are governed by the topological structure of the three-dimen sional polymer. Addition of water in the dried gels results in an increase of the dielectric constant by 10(5) times, while in the case of heavy water , this effect was weaker.