Poly(vinylidene fluoride)-Formvar blends: dielectric, miscibility and mechanical studies

One of the established means of achieving complementary properties in soft matter is polymer blending, and hence studies on polymer blends have gained immense significance. Despite a growing body of research, the mechanisms responsible for imparting properties to a polymer blend consisting of semi-crystalline and amorphous polymer remain poorly understood. Herein, we report the dielectric and mechanical properties of a semi-crystalline polymer poly(vinylidene fluoride) (PVDF), an amorphous polymer poly(vinyl formal) (PVF) and their blends. These blends were prepared by solution mixing and solid state mixing techniques and were found to be immiscible in both cases. Their immiscibility was further confirmed by time-temperature superposition analysis. A reduction of 75% in the energy dissipation factor of PVDF was observed in the blend. On the other hand, 45% enhancement was observed in the modulus value of the PVDF-PVF blend compared with pure PVDF, which could be due to inclusion of PVF which has a high glass transition temperature. Thus, this blend can be used for high-energy-density storage, energy harvesting and celestial applications, where low losses and robust devices are desirable.