The preparation of PVDF/clay nanocomposites and the investigation of their tribological properties

Poly(vinylidene fluoride) (PVDF) nanocomposites with different content of nanoclay were prepared by melt-intercalation method. The tribological behaviors of the PVDF/clay nanocomposites against 45# carbon steel ring were evaluated on a block-on-ring type (M-2000) wear tester. Transmission electron microscopy (TEM) observation showed the dispersion of nanoclay in PVDF matrix. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis found that nanoclay incorporation induced the PVDF crystal form to transform from α- to β-phase, and hence increased the materials polarity. Differential scanning calorimetry (DSC) analysis verified that the crystallinity of the nanocomposites decreased with the increasing nanoclay content. Nanoclay at 1–2 wt.% was effective for improving the tribological properties of neat PVDF, because the nanoclay at the low content may act as the reinforcing element to bore load and thus decrease the plastic deformation. The nanocomposite containing 5 wt.% nanoclay exhibited relatively high wear, weak compatibility between nanoclay and PVDF and also the decreased crystallinity may be responsible for the result.