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In this paper, flower-like ZnO (FZnO) particles were synthesized through a facile method using different precursor content and reaction time. The as-prepared ZnO particles were then characterized by scanning electron microscopy (SEM), and the results showed the production of particles with varied aspect ratios (5–14). Composites of poly (vinylidene fluoride) (PVDF) with FZnO were prepared and also studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier-transform infrared (FTIR). A slight reduction of thermal properties was noticed, where the degradation temperature decreased from 439 °C for neat PVDF to around 431–438 °C for the PVDF composites with FZnO. Besides, an increase of β-crystals was observed by incorporating these particles, shifting from 31% (neat PVDF) to 37% in the composites. Furthermore, the permeability coefficient to CO2 reduced around 13%, indicated that the composites with the obtained flower-like ZnO particles might have potential applications as a barrier layer in oil ducts pipelines compared with neat PVDF.

Zinc oxide particles in needle shape were synthesized by hydrothermal route varying the reactor rotation speed (600, 1200, and 1800 rpm). The synthesized particles and commercial nanosized ZnO were characterized through X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and scanning electronic microscopy (SEM), aiming to evaluate the influence of the synthesis variable on their thermal, morphological and chemical properties. In this study, the performance of composites comprising poly(vinylidene fluoride) (PVDF) matrix and ZnO synthesized particles, and commercial nanoparticles were compared. The composites were analyzed by XRD, TGA, FTIR, SEM, dynamic-mechanical analysis (DMA), and permeability to CO2. The results revealed that the particles synthesized even in micrometric diameter reduced the permeability much more than the commercial ZnO nanoparticles, therefore being more suitable for the application as inner pressure sheath in flexible ducts. Moreover, the ZnO needle-like particles with a lower dimension induced the PVDF β-phase to over 30%.

Nanocomposites of poly(vinylidene fluoride) (PVDF) with different commercial nanoparticles (rutile-TiO2, SiO2, α-Al2O3, Fe3O4) were prepared by melt extrusion and characterized. The effects of incorporating these nanoparticles in the matrix on the chemical, mechanical, thermal, and morphological properties were investigated. From the FTIR spectra, it was possible to calculate the percentage of α and β-phases of the PVDF matrix. The incorporation of nanoparticles increased the content of the β-crystals when compared with neat PVDF, indicating an improvement in the homogenization of the nanocomposite as observed in SEM images of PVDF/rutile-TiO2. The dynamic-mechanical analysis showed a decrease in storage and loss modulus in PVDF/α-Al2O3, but in both PVDF/rutile-TiO2 and PVDF/SiO2, only a small reduction was observed. The thermal properties also reduced after incorporation of these nanoparticles, except in PVDF/SiO2. For application as a barrier layer in oil ducts, the degradation temperature measured is appropriate to maintain the thermal stability at 130 °C (requested temperature). The experimental results indicated that PVDF/rutile-TiO2 and PVDF/SiO2 exhibited good potential properties, mainly by reducing permeability to CO2 with an increase of lagtime compared to neat PVDF.