Abstract
Multiwall carbon nanotube (CNT)-filled high density polyethylene (HDPE) nanocomposites were prepared by extrusion and considered for their suitability in the offshore sheathing applications. Transmission electron microscopy was conducted to analyse dispersion after bulk extrusion. Monolithic and nanocomposite samples were subjected to accelerated weathering and photodegradation (carbonyl and vinyl indices) characterisations, which consisted of heat, moisture (seawater) and UV light, intended to imitate the offshore conditions. The effects of accelerated weathering on mechanical properties (tensile strength and elastic modulus) of the nanocomposites were analysed. CNT addition in HDPE produced environmentally resilient nanocomposites with improved mechanical properties. The energy utilised to extrude nanocomposites was also less than the energy used to extrude monolithic HDPE samples. The results support the mass substitution of CNT-filled HDPE nanocomposites in high-end offshore applications.
Highlights
With oil and gas exploration moving towards deeper oceans with harsher thermo-mechanical environments, it has become ever so critical to find economical materials and umbilical systems providing appropriate tensile stiffness to withstand large loads induced by self-weight, sea current and the motion of the surface vessel
It can be concluded that the carbon nanotube (CNT) dispersion/exfoliation is much better in the nanocomposites with low CNT loadings (Figure 2b,c) where the fibre-like morphology of individual
CNT-filled high-density polyethylene (HDPE) nanocomposites with 4 wt% and 6 wt% loadings are the most optimal concentrations, as they provide a good balance between mechanical properties and resilience of mechanical properties against UV exposure for the offshore umbilical sheathing layer (Figure 1)
Summary
With oil and gas exploration moving towards deeper oceans with harsher thermo-mechanical environments, it has become ever so critical to find economical materials and umbilical systems providing appropriate tensile stiffness to withstand large loads induced by self-weight, sea current and the motion of the surface vessel. Umbilical cable (Figure 1) is an offshore product, utilised for the subsea oil and gas exploitation and related projects. The main aim of the cable is to provide a control and communication channel between the surface vessel and the subsea installations and equipment. The macro-composite structure contains multiple components and various types of engineering materials. Ferrous materials, such as steel armour wires, are used to provide the tension capability and to achieve the necessary internal stability against the high hydrostatic pressure [1]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call