Negative dielectric permittivity of poly(acrylic acid) pressed pellets

Spontaneously formed temperature-frequency zone of negative dielectric permittivity ε′< 0 was found in polymer-water system “poly(acylic acid) + 3 wt% of moisture”. Nucleation and evolution of the zone is demonstrated on ε′(f,T), ε″(f,T) and tgδ(f,T) 3D plots. Bound water release at T > 65 °C is thought to be the reason of this phenomenon. The frequency width of the zone steadily increases with temperature up to T = 83 °C, and then sharply increases at low-frequency side. This effect might be related to the anomalies in temperature dependencies of thermodepolarization currents in water at 83 °C. Spontaneous manifestation of ε′ < 0 phenomenon indicates that one can expect it in natural materials, including biopolymers, i.e. in living organisms.