Structural characteristics of poly(vinylidene fluoride)/clay nanocomposites

Poly(vinylidene fluoride) (PVDF)/clay nanocomposites with different clay contents were prepared by melt intercalation. The effects of clay on crystalline structure of PVDF were characterized, compared and discussed. For the nanocomposite containing 0.4 wt.% clay, the α phase coexists with the γ phase in the PVDF matrix in room temperature, however, the γ phase is unstable at 160 °C. When clay contents in the nanocomposites are greater 1 wt.%, the α phase coexists with the β phase. The β phase remains unchanged even after annealing. With increasing clay content, the location of the (021) reflection of α phase shifts to lower angle, while that of the (002) refection shifts to higher angle. Clay loading also induces the imperfection of α crystals. The results are attributed to the nucleation of PVDF on nanometer-size clay layers and the confining effect of nanometer-size clay on PVDF.