ИСТИНА

Ferroelectric polymers such as polyvinylidene fluoride (PVDF) and copolymers based on it exhibit piezoelectric and pyroelectric effects. Such properties allow them to be used as functional materials for creation of flexible thin-film sensors of pressure and temperature, as well as memory devices based on organic transistors and self-powered electronics . Double and ternary copolymers based on polyvinylidene fluoride with grafted polyethyl methacrylate (PEMA) and polyacrylonitrile (PAN) chains were synthesized by photoinduced reversible deactivation radical polymerization (RDRP) using a minimal amount of a catalytic system (Fig. 1). Four series of grafted polymers were obtained, and the dependence of the content of grafted chains on the synthesis time was investigated. It was shown that an increase in the degree of grafting leads to a nonlinear change in the dielectric properties and also affects the thermal and thermal-oxidative stability compared to the initial polymers. In a series of copolymers with grafted PEMA chains, the values of the dielectric constant decrease, but at the same time, dielectric losses also decrease. Moreover, an increase in the degree of grafting significantly improves the film-forming properties of all the polymers obtained by reducing the degree of crystallinity and lowering the melting point.