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

Abstract

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. K E Y W O R D S composites, nanoparticles, nanotubes, oil and gas, thermoplastics 1 | INTRODUCTION Flexible pipes are transportation lines used to connect the wells, in the seabed, to the production units, transporting oil and gas fluids in offshore applications. These pipes possess a multilayer structure, with polymeric layers and helically wound metallic wires, designed to withstand tensile loads, high pressure, and temperature. 1-3 Different layer combinations are possible, depending on the intended service conditions. Still, in general, flexible risers present a typical configuration, with the following layers: interlocked carcass (metal),

Mechanical, rheological, and carbon dioxide barrier properties of polyvinylidene fluoride/TiO2composites for flexible riser applications

“…The diffraction peaks of primary PVDF at 2 θ = 18.03°, 18.73°, 20.25°, and 26.86° are all clearly observed. These diffraction peaks belong to crystal planes of (100), (020), (110), and (021) of the α crystalline phase of PVDF, respectively 25 . The rise in TiO 2 content indicates that certain crystal types do not change in the PVDF/TiO 2 composite, and the change in peak shape and peak width may only be due to a change in relative content.…”

“…These diffraction peaks belong to crystal planes of (100), (020), (110), and (021) of the α crystalline phase of PVDF, respectively. 25 The rise in TiO 2 content indicates that certain crystal types do not change in the PVDF/TiO 2 composite, and the change in peak shape and peak width may only be due to a change in relative content. 2θ = 38.6 -38.9 can be considered as the mixed peak of the α phase (131) and γ phase (211).…”

Synthesis of functionalized ZnO nanoflake loaded polyvinylidene fluoride composites with enhanced energy storage properties

“…While peaks allocated to α phase are represented at 1380, 975, 797 and 769 cm −1 . [ 24 ] Here incorporation of ZnO@APTES in PVDF increases the intensity of IR absorption for both α and β phases of PVDF. But the absorbance of polar β peaks is predominantly higher than non‐polar α peaks due to the high polarity of ZnO@APTES.…”

Dynamic Mechanical and Creep Behaviour of Meltspun PVDF Nanocomposite Fibers

“…Moreover, it was discovered that the storage modulus of the nanocomposite fibers is higher than pure PVDF, with PVDF/rGO having the highest E′ compared to the other fibers. This can be attributed to the reinforcing effect [ 41 ] of rGO. rGO sheets have a high aspect ratio with strong interfacial adhesion for the integration in the PVDF matrix [ 42 ].…”