Strong thermoplastic elastomers created using nickel nanopowder

Abstract

We have decided to investigate whether addition of nickel (Ni) to a thermoplastic elastomer (TPE) will make TPE properties better for demanding applications. We have found that Ni particles moved well during low (100 °C) temperature blending, with the polymer providing more uniform particle dispersion. In contrast, at 160 °C, lower viscosity prevented particle dispersion and supported Ni agglomerations. All samples processed at low temperatures showed increased (by ≈10 °C) melting temperatures, higher crystallinity, and a 1.5 times higher Young’s modulus E. While addition of Ni increases brittleness B of the blends, and so does vulcanization, a combination of both treatments lowers B. Some Ni particles go into existing free volume spaces in vulcanized materials thus enhancing mechanical properties including the storage modulus E′; some other filler particles create new free volume pockets increasing the elongation at break; thus, Ni particles at both kinds of locations provide lower values of brittleness. The addition of 0.5 wt% Ni particles to the uncured TPE matrix decreases the amount of extracted gel by 68.0 wt%. We used both Ni and oxidized Ni; they bestow similar properties on the TPE while providing stronger and less brittle materials than neat TPE.