Effect of POSS nanofiller on structure, thermal and mechanical properties of PVDF matrix

Nanocomposites composed of a poly(vinylidene fluoride) (PVDF) matrix and 0, 3, 5, and 8 wt% trifluoropropyllsobutyl POSS (FPB-POSS) were obtained by the solvent evaporation method. The morphology, crystallization, and thermal properties were investigated. POSS presented in the form of micron-sized aggregations of particles distributed in the PVDF matrix. With the addition of POSS, larger particles of PVDF chains were generated with particle sizes increasing from 40 to 240 nm. A relative high fraction of b phase was observed in the composites. The thermal degradation of PVDF was not significantly affected by FPB-POSS under a nitrogen atmosphere. The mechanical property was investigated by a nanoindentation test to study the influence of FPB-POSS. FPB-POSS acting as nanofiller led to remarkable improvement in mechanical properties, including hardness and elastic property. The size effect was more evident with larger addition of FPB-POSS due to the surface roughness.