Poly(vinylidene fluoride) with zinc oxide and carbon nanotubes applied to pressure sheath layers in oil and gas pipelines

• Published in: Journal of applied polymer science Vol. 138; no. 14
• Main Authors: Gondim, Fernanda Fabbri, Tienne, Lucas Galhardo Pimenta, Macena da Cruz, Barbara de Salles, Chaves, Erica Gervasoni, Carvalho Peres, Augusto Cesar, Marques, Maria de Fatima Vieira
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 10.04.2021; Wiley Subscription Services, Inc
• Subjects: Composite materials; composites; Contact angle; Degree of crystallinity; Differential pressure; Differential scanning calorimetry; Dimensional stability; Dynamic mechanical analysis; Flexible pipes; Gas pipelines; High aspect ratio; High temperature; Hydrophobicity; Infrared analysis; Infrared spectroscopy; Internal pressure; Materials science; Mechanical properties; Multi wall carbon nanotubes; nanoparticles; nanotubes; Natural gas; oil and gas; Particulate composites; Permeability; Permeability tests; Petroleum pipelines; Polymers; Scanning electron microscopy; Sheaths; Thermogravimetric analysis; thermoplastics; Time lag; Zinc oxides
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.50157

In this work, PVDF composites containing 0.2% (m/m) of carbon nanotubes (MWCNTs), PVDF with 5.0% (m/m) of zinc oxide (ZnO), and composites containing both particles in the same contents in the matrix were melt processed in a mini‐extruder machine with double screws, using the counter‐rotation mode. Composites were characterized by scanning electron microscopy (SEM), Fourier‐transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X‐ray diffraction (XRD), dynamic‐mechanical analysis (DMA), and contact angle tests (CA). The samples presented the predominance of the α phase, with an increased degree of crystallinity as well as an increase in dimensional stability by incorporating both fillers, showing a synergistic effect between these particles, as shown on FTIR, DSC, and XRD results. SEM images showed a good dispersion of high aspect ratio particles. In general, DMA and TGA analysis showed that composites had not decreased their thermal and mechanical performance when compared to neat PVDF. Results of CA analysis showed an increase in the hydrophobicity of the sample containing MWCNTs. Permeability tests were also performed using a differential pressure system, combining high temperature and pressure, obtaining permeability measures and time lag. This work presents an alternative of composite materials, suggesting its application in the internal pressure sheath layers of oil and gas flexible pipes.