Using XPS and FTIR spectroscopies to investigate Polyamide 11 degradation on aging flexible risers

Norsk Hydro has more than 150 flexible dynamic risers and service lines in operation. Norsk Hydro’s experience with flexible risers started in 1987 when Petrojarl 1 commenced test production at the Oseberg Field. The paper tells the story about Norsk Hydro’s experience through the 15 years of trials with a new and complicated product. This paper will focus on “what went wrong”. This may seem unfair to the product! However, without flexibles we would probably not have seen such successful field developments as the Troll B and C, Njord, Visund and Snorre B. Challenging production and installation schemes have been put forward and fulfilled. However, hopefully this paper can give an insight in failure modes, and so forth give input to enhanced solutions in order to avoid similar situations in the future. This paper gives an overview over the different approaches which have been taken to give a better qualification of the lifetime prediction of the risers. Some of the specific projects will be presented in detail in other papers on this conference.

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Managing Fatigue In Deepwater Flexible Risers

10.4043/19443-ms ◽

2008 ◽

Author(s):

Niels-J. Rishoj Nielsen ◽

Nick Weppenaar ◽

Dorthe de la Cour ◽

Claus Kristensen

Keyword(s):

Flexible Risers

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Wear behavior of polyamide 11 reinforced with titanate nanotubes

Journal of Thermoplastic Composite Materials ◽

10.1177/08927057211013391 ◽

2021 ◽

pp. 089270572110133

Author(s):

Ayrton Alef Castanheira Pereira ◽

José Roberto Moraes d’Almeida

Keyword(s):

Wear Behavior ◽

Roughness Parameter ◽

Sodium Content ◽

Titanate Nanotubes ◽

Wear Performance ◽

Polyamide 11 ◽

High Sodium ◽

Parameter Variations ◽

Key Factor ◽

Open Question

Besides polyamide 11 (PA 11) outstanding properties, wear performance is considered a key factor for its continued widespread use. TiTanate NanoTubes (TTNT) have a huge potential as reinforcement in polymer matrix nanocomposites, and although nanotubes reinforcement capacity is well understood, its effect on tribological characteristics is still an open question. Thus, the present work has as objective to study the wear behavior of PA 11 and its nanocomposites, highlighting TTNT loading, functionalization and sodium content effects. Seeking the possibility to tailor properties, surface topography is investigated. Based on parameter classification, correlation and functional sense, an ideal roughness parameter set is defined. By taking measurements in X- and Y-axis, parameter variations and sensibility are also analyzed. From the results, maximum wear resistance can be reached in functionalized samples with low TTNT loading and high sodium content. Some roughness parameters demonstrate a moderate to strong correlation with wear performance. Parameter variations are mainly attributed to the non-stationarity of the surface.

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A novel recycled polyethylene terephthalate/polyamide 11 (rPET/PA11) thermoplastic blend

Progress in Rubber Plastics and Recycling Technology ◽

10.1177/14777606211001074 ◽

2021 ◽

pp. 147776062110010

Author(s):

Zahid Iqbal Khan ◽

Zurina Binti Mohamad ◽

Abdul Razak Bin Rahmat ◽

Unsia Habib ◽

Nur Amira Sahirah Binti Abdullah

Keyword(s):

Mechanical Properties ◽

Impact Strength ◽

Flexural Strength ◽

Polyethylene Terephthalate ◽

Practical Implication ◽

Polyamide 11 ◽

Recycled Polyethylene ◽

Twin Screw ◽

Electron Microscopy Analysis ◽

The Impact

This work explores a novel blend of recycled polyethylene terephthalate/polyamide 11 (rPET/PA11). The blend of rPET/PA11 was introduced to enhance the mechanical properties of rPET at various ratios. The work’s main advantage was to utilize rPET in thermoplastic form for various applications. Three different ratios, i.e. 10, 20 and 30 wt.% of PA11 blend samples, were prepared using a twin-screw extruder and injection moulding machine. The mechanical properties were examined in terms of tensile, flexural and impact strength. The tensile strength of rPET was improved more than 50%, while the increase in tensile strain was observed 42.5% with the addition of 20 wt.% of PA11. The improved properties of the blend were also confirmed by the flexural strength of the blends. The flexural strength was increased from 27.9 MPa to 48 MPa with the addition of 30 wt.% PA11. The flexural strain of rPET was found to be 1.1%. However, with the addition of 10, 20 and 30 wt.% of PA11, the flexural strain was noticed as 1.7, 2.1, and 3.9% respectively. The impact strength of rPET/PA11 at 20 wt.% PA11 was upsurged from 110.53 to 147.12 J/m. Scanning electron microscopy analysis revealed a dispersed PA11 domain in a continuous rPET matrix morphology of the blends. This work practical implication would lead to utilization of rPET in automobile, packaging, and various industries.

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A Comprehensive Investigation on 3D Printing of Polyamide 11 and Thermoplastic Polyurethane via Multi Jet Fusion

Polymers ◽

10.3390/polym13132139 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2139

Author(s):

Wei Shian Tey ◽

Chao Cai ◽

Kun Zhou

Keyword(s):

Tensile Strength ◽

Flexural Strength ◽

Wear Rate ◽

Mechanical Performance ◽

Thermoplastic Polyurethane ◽

Print Quality ◽

Polyamide 11 ◽

Powder Bed

Multi Jet Fusion (MJF) is a recently developed polymeric powder bed fusion (PBF) additive manufacturing technique that has received considerable attention in the industrial and scientific community due to its ability to fabricate functional and complex polymeric parts efficiently. In this work, a systematic characterization of the physicochemical properties of MJF-certified polyamide 11 (PA11) and thermoplastic polyurethane (TPU) powder was conducted. The mechanical performance and print quality of the specimens printed using both powders were then evaluated. Both PA11 and TPU powders showed irregular morphology with sharp features and had broad particle size distribution, but such features did not impair their printability significantly. According to the DSC scans, the PA11 specimen exhibited two endothermic peaks, while the TPU specimen exhibited a broad endothermic peak (116–150 °C). The PA11 specimens possessed the highest tensile strength in the Z orientation, as opposed to the TPU specimens which possessed the lowest tensile strength along the same orientation. The flexural properties of the PA11 and TPU specimens displayed a similar anisotropy where the flexural strength was highest in the Z orientation and lowest in the X orientation. The porosity values of both the PA11 and the TPU specimens were observed to be the lowest in the Z orientation and highest in the X orientation, which was the opposite of the trend observed for the flexural strength of the specimens. The PA11 specimen possessed a low coefficient of friction (COF) of 0.13 and wear rate of 8.68 × 10−5 mm3/Nm as compared to the TPU specimen, which had a COF of 0.55 and wear rate of 0.012 mm3/Nm. The PA11 specimens generally had lower roughness values on their surfaces (Ra < 25 μm), while the TPU specimens had much rougher surfaces (Ra > 40 μm). This investigation aims to uncover and explain phenomena that are unique to the MJF process of PA11 and TPU while also serving as a benchmark against similar polymeric parts printed using other PBF processes.

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Surface Characterisation and Fatigue Strength of Corroded Armour Wire

Volume 6B: Pipeline and Riser Technology ◽

10.1115/omae2014-24140 ◽

2014 ◽

Cited By ~ 1

Author(s):

Stig Berge ◽

Ting Wang ◽

Nina Langhelle

Keyword(s):

Fatigue Strength ◽

Surface Defects ◽

Sea Water ◽

Corrosion Damage ◽

Water Flooding ◽

Surface Characterisation ◽

Electron Scanning Microscopy ◽

Flexible Risers ◽

The Wire ◽

Fatigue Notch Factor

Tensile armour wire from two flexible risers was fatigue tested for assessment of SN-curves. Both risers had been subjected to sea water flooding of the annulus for several years. The wire was corroded in the form of pits, however, the cross section was not significantly reduced. Reference wire from the same batches of material that had not been subjected to corrosion was also tested. Testing was carried out in air, to investigate the effect of accumulated corrosion damage in terms of a fatigue notch factor. The fatigue strength of the corroded wire was significantly reduced, corresponding to a fatigue notch factor in the range 1.5–1.7. The wire was examined by optical and by electron scanning microscopy and the surface defects were characterised.

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