Characteristics and corrosion protection of polypyrrole doped with salicylate anions on CT3 steel passivated by molydate

2021 ◽  
Vol 72 (7) ◽  
pp. 789-799
Author(s):  
Lan Hoang Thi Tuyet ◽  
Hoan Lai Thi

In recent years, the conducting polymers have attracted much attention in research and development because of their applications in medical and civil engineering. Here, the salicylate doped polypyrrole films were prepared on the carbon steel surface and their corrosion protection in 3 % NaCl solution were studied. Polypyrrole (Ppy) film was electrochemically synthesised with constant current techniques in a sodium salicylate solution (0.05M, 0.1M, 0.15M) and 0.1M pyrrole monomer on mild CT3 steel electrode passivated by molybdate. The morphological, structural, composition and thermal properties of salicylate doped Ppy films were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) techniques. The anti-corrosion ability of these films was assessed by electrochemical measurements in 3 % NaCl solution. The obtained results suggested that salicylate anions contributed in corrosion protection ability of Ppy films for mild steel electrode. The concentration of sodium salicylate of 0.1M and pyrrole of 0.1M is most suitable for preparation of good protection coating. The self-healing mechanism has been also mentioned for salicylate doped Ppy films on CT3 steel substrate.

Author(s):  
Shaiful Rizam Shamsudin ◽  
Zin Wen Sim ◽  
Rajaselan Wardan ◽  
Nadia Nadhira Mohd Jamalullalel ◽  
Azmi Rahmat

Author(s):  
Adnan Khan ◽  
Amani Hassanein ◽  
Abdul Shakoor ◽  
Ramazan kahraman ◽  
Fatima Montemor ◽  
...  

Corrosion is one of the critical causes of material loss in metal components. This research is focused on the synthesis, and electrochemical properties of polyelectrolyte layered microcapsules (PMCs) reinforced smart polymeric coating for corrosion protection of steel substrates. For this purpose, monolayer urea-formaldehyde microcapsules encapsulated with linalyl acetate (MLMCs) was synthesized by Insitu polymerization. In the next step, phenylthiourea (PTU) was loaded between the layers of polyelectrolytes; polyethylenimine (PEI) & sulfonated polyether ether ketone (SPEEK) on the surface of MLMCs using layer by layer technique. The MLMCs are sensitive to mechanical stress while the PTU in PMCs is triggered by pH stimulus. The newly designed PMCs has linalyl acetate in the core and PTU in the polyelectrolyte layers. Furthermore, 6 wt.% of both MLMCs and PMCs are dispersed in the epoxy resin and applied on the clean steel substrate. Performance comparison showed that the epoxy resin reinforced with PMCs demonstrate enhanced thermal, self-healing and electrochemical properties. This improved performance can be attributed to the efficient release of the self-healing agent and corrosion inhibitor from the PMCs. Conclusively, the epoxy coatings modified with PMCs can be a novel organic coating for the corrosion protection of oil and gas industries.


2021 ◽  
Author(s):  
Amani Hassanein ◽  
Adnan Khan ◽  
R.A. Shakoor ◽  
Ramazan Kahraman

Corrosion is one of the challenging issues faced by many industries, causing substantial economic losses every year due to the degradation of metallic parts, raising many safety concerns. Therefore, it is of utmost relevance to developing strategies that can repair the damaged part of the coatings to protect the base metal and restrict the initiation of corrosion. Towards this direction, the concept of double-layered polymeric coatings (DLPCs) for corrosion protection is introduced as a novel strategy to bring different healing functionalities into coating matrices. The developed DLPCs are composed of a top layer containing 5wt. % of melamine urea-formaldehyde microcapsules (MUFMC) encapsulating boiled linseed oil (self-healing agent), and bottom layer having 3wt. % benzotriazole (corrosion inhibitor) loaded into halloysite nanotubes (HNTs). The DLPCs were developed on mild steel substrate employing a doctor blade technique. The electrochemical analyses indicates that the DLPCs demonstrate improved corrosion resistant properties. This improved performance can be ascribed to the efficient triggering of the individual carriers in the quarantined matrix, resulting in enhanced corrosion efficiency of the DLPCs. The promising characteristics of DLPCs make them suitable for many potential industrial applications.


2020 ◽  
Vol 117 (6) ◽  
pp. 610
Author(s):  
Nadia Hammouda ◽  
Kamel Belmokre

Organic coatings are widely employed in the corrosion protection of most metal surfaces, particularly steel. They provide a barrier against corrosive species present in the environment, due to their high resistance to oxygen, water and ions transport. This study focuses on the evaluation of corrosion protection performance of epoxy paint on the carbon steel surface in chloride environment (3% NaCl) by Electrochemical Impedance Spectroscopy (EIS). The electrochemical behavior of painted surface was estimated by EIS parameters that contained paint film resistance, paint film capacitance and double layer capacitance. On the basis of calculation using EIS spectrums it was observed that pore resistance (Rpore) decreased with the appearance of doubled layer capacitance (Cdl) due to the electrolyte penetration through the film. This was further confirmed by the decrease of diffusion resistance (Rd) which was also the indicator of the deterioration of paint film protectiveness. Microscopic analyses have shown that oxidation dominates the corroded surfaces.


2018 ◽  
Author(s):  
Hakeem K. Henry ◽  
Sang Bok Lee

The PMo<sub>12</sub>-PPy heterogeneous cathode was synthesized electrochemically. In doing so, the PMo<sub>12</sub> redox-active material was impregnated throughout the conductive polymer matrix of the poly(pyrrole) nanowires. All chemicals and reagents used were purchased from Sigma-Aldrich. Anodized aluminum oxide (AAO) purchased from Whatman served as the porous hard template for nanowire deposition. A thin layer of gold of approximately 200nm was sputtered onto the disordered side of the AAO membrane to serve as the current collector. Copper tape was connected to the sputtered gold for contact and the device was sealed in parafilm with heat with an exposed area of 0.32 cm<sup>2</sup> to serve as the electroactive area for deposition. All electrochemical synthesis and experiments were conducted using a Bio-Logic MPG2 potentiostat. The deposition was carried out using a 3-electrode beaker cell setup with a solution of acetonitrile containing 5mM and 14mM of the phosphomolybdic acid and pyrrole monomer, respectively. The synthesis was achieved using chronoamperometry to apply a constant voltage of 0.8V vs. Ag/AgCl (BASi) to oxidatively polymerize the pyrrole monomer to poly(pyrrole). To prevent the POM from chemically polymerizing the pyrrole, an injection method was used in which the pyrrole monomer was added to the POM solution only after the deposition voltage had already been applied. The deposition was well controlled by limiting the amount of charge transferred to 300mC. Following deposition, the AAO template was removed by soaking in 3M sodium hydroxide (NaOH) for 20 minutes and rinsed several times with water. After synthesis, all cathodes underwent electrochemical testing to determine their performance using cyclic voltammetry and constant current charge-discharge cycling in 0.1 M Mg(ClO<sub>4</sub>)<sub>2</sub>/PC electrolyte. The cathodes were further characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), and x-ray photoelectron spectroscopy (XPS).


Author(s):  
Narubeth Lorwanishpaisarn ◽  
Natwat Srikhao ◽  
Kaewta Jetsrisuparb ◽  
Jesper T. N. Knijnenburg ◽  
Somnuk Theerakulpisut ◽  
...  

2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
Muhammad Ashraff Ahmad Seri ◽  
Esah Hamzah ◽  
Abdelsalam Ahdash ◽  
Mohd Fauzi Mamat

Recently, self-healing coating is classified as one of the smart coatings which has the ability to heal or repair damage of the coating to prevent further corrosion. The aim of this study is to synthesize the self-healing coatings from polymeric material and evaluate the performance and their corrosion behavior when coated on steel substrates. The corrosion tests were performed using immersion test and salt spray test method at room temperature. The immersion test shows that self-healing coating gives lower corrosion rate compared to pure epoxy paint, with a value of 0.02 and 0.05 mm/year respectively. Also, salt spray test shows similar trend as the immersion test, which is 0.11 and 0.19 mm/year for self-healing coating and pure epoxy paint respectively. While uncoated samples without any protection corroded at 0.89 mm/year. It was also found that the damage on self-healing coating was covered with zeolite from the microcapsules indicating that the self-healing agent was successfully synthesized and could function well. In other words, self-healing coating shows better corrosion resistance compared to the pure epoxy coating on steel substrate.


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