Mechanical improvement of P(VDF-TrFE) /nickel nanowires conductive nanocomposites: Influence of particles aspect ratio

Nickel nanowires with high aspect ratio (250) were elaborated and incorporated into poly(vinylidene difluoride-trifluoroethylene) up to 30 vol% via solvent mixing way. These nanocomposites are characterized by a conductive behavior with a high electrical conductivity value (10² S m^?1) above a very low percolation threshold (0.75 vol% of metallic nanowires). The introduction of nanowires strongly depressed the matrix crystallinity. Static and dynamic mechanical analysis have been realized at low nanowire volume fraction (< 10 vol%). Below 5 vol% of nanowires, nanocomposites remain ductile. The dynamic mechanical properties are related to the volume fraction of nanowires. A strong increase of the viscoelastic contribution related to the increase of the percentage of amorphous phase is observed. The major effect is the increase of the rubbery modulus. The highest increase of 300% is obtained for only 5 vol% of nanowires; it represents an original mechanical result for low filled composites. The dependence versus nanowire content has been described by adapting the Halpin–Tsai model to high aspect ratio filler. Metallic nanowires create additional entanglements that are randomly distributed in the rubbery polymeric matrix. With their low percolation threshold, metallic nanowires based nanocomposites constitute a new class of multifunctional materials with a high conductivity associated with a ductile polymer matrix characterized by a high rubbery modulus.