Dielectric and thermal–mechanical properties of hybrid organic–inorganic polymer systems based on isocyanate-containing oligomers

Hybrid organic–inorganic polymer systems (OIS) were obtained in reactions of the organic oligomer (macrodiisocyanate + poly(isocyanate) (MDI + PIC)) which has free isocyanate groups with inorganic oligomer – sodium silicate (SS). The structure of OIS was formed as two interpenetrated networks: an elastic network as a result of reactions MDI–SS and a rigid network PIC–SS. Depending on MDI/PIC ratio, one of the network features is prevailing as attested to by dielectric, electrical and thermal–mechanical experiments. The elastic network MDI–SS possesses high values of dielectric parameters ε′, tan δ and conductivity σ whereas for the rigid network PIC–SS the values of these characteristics are much lower and are typical for usual thermosets.