Boronic Ester-Polyurethane as a Self-Healing Coating Material for Offshore Top Side Structures Application

2021 ◽  
Author(s):  
Mohd Shamsul Farid Samsudin ◽  
Norfarah Diana Aba ◽  
Muzdalifah Zakaria ◽  
Azmi Mohammed Nor ◽  
Russell Varley ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Coating Layer ◽  
Salt Spray ◽  
The Self ◽  
Self Healing ◽  
Humidity Level ◽  
Healing System ◽  
Healing Efficiency ◽  
Harsh Conditions

Abstract Polymer coatings, especially epoxy and polyurethane paint systems, have been widely used to prevent corrosion of metallic components and structures. However, due to environmental and mechanical effects, the barrier efficiency of the coatings may be substantially compromised during transportation and service, as demonstrated by localized scratches, delamination, or stress-related microcracks. Application of a self-healing coating that can restore damages and recover its performance with minimal external intervention could prevent corrosion at the damaged coating. In this present work, the healing efficiency and long-term durability of Boronic Ester (BE) blended with Polyurethane (PU) as a self-healing system for top side coating of offshore platform structures was investigated. The BE was mixed at a ratio of 50:50 with PU resin and applied as a top layer on a PU coated steel plate with a thickness of approximately 300-350 μm. The healing efficiency, mechanical performance, and durability under simulated environmental conditions such as salt spray and UV were investigated according to the related ASTM standards. As a first step, the electrical impedance spectroscopy (EIS) and 3D profilemeter microscope were used to assess the healing ability of the scratched coating at room temperature and humidity level of 85 %. The mechanical performance of the self-healing coating layer was evaluated using a pull off adhesion test to investigate the compatibility of the self-healing system with the existing commercial PU topcoat system, while a long term 3000 hours salt spray and 4200 hours cyclic UV test were performed to evaluate the self-healing coating's durability in harsh conditions. Preliminary assessment using EIS and 3D profilemeter microscopes on the scratched PU/BE self-healing coating revealed significant healing efficiency of more than 80% for healing condition at ambient temperature and humidity level of 85%. The self-healing coating layer also demonstrated excellent adhesion efficiency, with adhesion greater than 300 psi suggesting good compatibility of the BE-PU layer with commercial PU coating. The salt spray and cyclic UV tests that were performed to determine the durability of the self-healing coating revealed that the 50BE/50PU layer remained intact and exhibited good healing performance with more than 80% efficiency even after exposure to harsh conditions. The findings from the study demonstrated that the BE/PU material has the potential to be used as a self-healing system for topside coating of offshore platforms structures, thereby lowering maintenance costs.

scholarly journals Self-Healing of Concrete Cracks by Ceramsite-Loaded Microorganisms

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Xu ◽  
Xianzhi Wang ◽  
Junqing Zuo ◽  
Xiaoyan Liu
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Heating Temperature ◽  
Concrete Strength ◽  
The Self ◽  
Self Healing ◽  
Healing Efficiency ◽  
Maximum Crack ◽  
Harsh Conditions ◽  
Urea Decomposition

Protective carrier is essential for the self-healing of concrete cracks by microbially induced CaCO3 precipitation, owing to the harsh conditions in concrete. In this paper, porous ceramsite particles are used as microbial carrier. Heat treatment and NaOH soaking are first employed to improve the loading content of the ceramsite. The viability of bacterial spores is assessed by urea decomposition measurements. Then, the self-healing efficiency of concrete cracks by spores is evaluated by a series of tests including compressive strength regain, water uptake, and visual inspection of cracks. Results indicate that heat treatment can improve the loading content of ceramsite while not leading to a reduction of concrete strength by the ceramsite addition. The optimal heating temperature is 750°C. Ceramsite particles act as a shelter and protect spores from high-pH environment in concrete. When nutrients and spores are incorporated in ceramsite particles at the same time, nutrients are well accessible to the cells. The regain ratio of the compressive strength increases over 20%, and the water absorption ratio decreases about 30% compared with the control. The healing ratio of cracks reaches 86%, and the maximum crack width healed is near 0.3 mm.

scholarly journals Evaluation of the Self-Healing Ability of Mortar Mixtures Containing Superabsorbent Polymers and Nanosilica

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 380 ◽  
Author(s):  
Gerlinde Lefever ◽  
Didier Snoeck ◽  
Dimitrios G. Aggelis ◽  
Nele De Belie ◽  
Sandra Van Vlierberghe ◽  
...  
Keyword(s):  
Crack Width ◽  
Mechanical Performance ◽  
Cementitious Material ◽  
The Self ◽  
Optical Measurements ◽  
Self Healing ◽  
Superabsorbent Polymers ◽  
Healing Efficiency ◽  
Good Healing ◽  
External Conditions

Addition of superabsorbent polymers (SAPs) to cementitious mixtures promotes the self-healing ability of the material. When cracking occurs; SAPs present inside the crack will swell upon contact with water and subsequently release this water to stimulate the further hydration of unhydrated cement particles and the calcium carbonate crystallization. However; the inclusion of SAPs affects the mechanical performance of the cementitious material by the creation of macro-pores as water is retracted from the swollen SAP. To counteract the reduction in strength, part of the cement is replaced by nanosilica. In this research, different mixtures containing either SAPs or nanosilica and a combination of both were made. The samples were subjected to wet–dry cycles simulating external conditions, and the self-healing efficiency was evaluated by means of the evolution in crack width, by optical measurements, and a water permeability test. In samples containing SAPs, an immediate sealing effect was observed and visual crack closure was noticed. The smaller influence on the mechanical properties and the good healing characteristics in mixtures containing both nanosilica and SAPs are promising as a future material for use in building applications.

A MICROCAPSULE TECHNOLOGY BASED SELF-HEALING SYSTEM FOR CONCRETE STRUCTURES

2013 ◽  
Vol 07 (03) ◽  
pp. 1350014 ◽  
Author(s):  
BIQIN DONG ◽  
NINGXU HAN ◽  
MING ZHANG ◽  
XIANFENG WANG ◽  
HONGZHI CUI ◽  
...  
Keyword(s):  
Urea Formaldehyde ◽  
Concrete Structures ◽  
The Self ◽  
Polymerization Reaction ◽  
Formaldehyde Resin ◽  
Self Healing ◽  
Cementitious Composite ◽  
Healing System ◽  
Healing Efficiency ◽  
Healing Agent

In the study, a novel microcapsule technology based self-healing system for concrete structures has been developed. Through situ-polymerization reaction, the microcapsule is formed by urea formaldehyde resin to pack the epoxy material, which is applied to cementitious composite to achieve self-healing effect. The experimental results revealed that the self-healing efficiency of the composite can be accessed from the recovery of the permeability and strength for the cracked cementitious specimens as the healing agent in the microcapsule acting on the cracks directly. Scanning electronic microscope (SEM/EDX) results show that the epoxy resin is released along with the cracking of the cementitious composite and prevent from cracks continued growth. Further studies show that the self-healing efficiency is affected by the pre-loading of composite, particle size of microcapsule, aging duration of healing agent and so on.

ANTICORROSION PERFORMANCE OF SELF-HEALING POLYMERIC COATINGS ON LOW CARBON STEEL SUBSTRATES

2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
Muhammad Ashraff Ahmad Seri ◽  
Esah Hamzah ◽  
Abdelsalam Ahdash ◽  
Mohd Fauzi Mamat
Keyword(s):  
Steel Substrate ◽  
Salt Spray ◽  
Immersion Test ◽  
Salt Spray Test ◽  
Test Method ◽  
The Self ◽  
Self Healing ◽  
Pure Epoxy ◽  
Steel Substrates ◽  
Epoxy Paint

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.

Effect of Using Magnesium Acetate on the Self-Healing Efficiency of Hydrogel-Encapsulated Bacteria in Concrete

2021 ◽  
Author(s):  
Ricardo Hungria ◽  
Momen Mousa ◽  
Marwa Hassan ◽  
Omar Omar ◽  
Andrea Gavilanes ◽  
...  
Keyword(s):  
The Self ◽  
Magnesium Acetate ◽  
Self Healing ◽  
Healing Efficiency ◽  
Encapsulated Bacteria

scholarly journals Design of self-healing catalysts for aircraft application

2018 ◽  
Vol 9 (6) ◽  
pp. 723-736 ◽  
Author(s):  
Elisa Calabrese ◽  
Pasquale Longo ◽  
Carlo Naddeo ◽  
Annaluisa Mariconda ◽  
Luigi Vertuccio ◽  
...  
Keyword(s):  
Ruthenium Catalysts ◽  
The Self ◽  
Self Healing ◽  
Catalytic Systems ◽  
Content Type ◽  
Aerospace Applications ◽  
Healing Efficiency ◽  
Relevant Role ◽  
Aircraft Application

PurposeThe purpose of this paper is to highlight the relevant role of the stereochemistry of two Ruthenium catalysts on the self-healing efficiency of aeronautical resins.Design/methodology/approachHere, a very detailed evaluation on the stereochemistry of two new ruthenium catalysts evidences the crucial role of the spatial orientation of phenyl groups in the N-heterocyclic carbene ligands in determining the temperature range within the curing cycles is feasible without deactivating the self-healing mechanisms (ring-opening metathesis polymerization reactions) inside the thermosetting resin. The exceptional activity and thermal stability of the HG2MesPhSyncatalyst, with the syn orientation of phenyl groups, highlight the relevant potentiality and the future perspectives of this complex for the activation of the self-healing function in aeronautical resins.FindingsThe HG2MesPhSyncomplex, with the syn orientation of the phenyl groups, is able to activate metathesis reactions within the highly reactive environment of the epoxy thermosetting resins, cured up to 180°C, while the other stereoisomer, with the anti-orientation of the phenyl groups, does not preserve its catalytic activity in these conditions.Originality/valueIn this paper, a comparison between the self-healing functionality of two catalytic systems has been performed, using metathesis tests and FTIR spectroscopy. In the field of the design of catalytic systems for self-healing structural materials, a very relevant result has been found: a slight difference in the molecular stereochemistry plays a key role in the development of self-healing materials for aeronautical and aerospace applications.

scholarly journals Preparation and Properties of Self-Healing and Self-Lubricating Epoxy Coatings with Polyurethane Microcapsules Containing Bifunctional Linseed Oil

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1578 ◽  
Author(s):  
Haijuan Yang ◽  
Qiufeng Mo ◽  
Weizhou Li ◽  
Fengmei Gu
Keyword(s):  
Interfacial Polymerization ◽  
Electrochemical Impedance ◽  
Linseed Oil ◽  
Salt Spray ◽  
Average Diameter ◽  
Organic Coating ◽  
Epoxy Coating ◽  
The Self ◽  
Self Healing ◽  
Pure Epoxy

An organic coating is commonly used to protect metal from corrosion, but it is prone to failure due to microcracks generated by internal stress and external mechanical action. The self-healing and self-lubricating achieved in the coating is novel, which allows an extension of life by providing resistance to damage and repair after damage. In this study, a new approach to microencapsulating bifunctional linseed oil with polyurethane shell by interfacial polymerization. Moreover, the self-healing and self-lubricating coatings with different concentrations of microcapsules were developed. The well-dispersed microcapsules showed a regular spherical morphology with an average diameter of ~64.9 μm and a core content of 74.0 wt.%. The results of the salt spray test demonstrated that coatings containing microcapsules still possess anticorrosion, which is improved with the increase of microcapsules content, after being scratched. The results of electrochemical impedance spectroscopy showed a |Z|f=0.01Hz value of 104 Ω·cm2 for pure epoxy coating after being immersed for 3 days, whereas the coating with 20 wt.% microcapsules was the highest, 1010 Ω·cm2. The results of friction wear showed that the tribological performance of the coating was enhanced greatly as microcapsule concentration reached 10 wt.% or more, which showed a 86.8% or more reduction in the friction coefficient compared to the pure epoxy coating. These results indicated that the coatings containing microcapsules exhibited excellent self-healing and self-lubricating properties, which are positively correlated with microcapsules content.

scholarly journals Healing Performance of a Self-Healing Protective Coating According to Damage Width

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 543
Author(s):  
Dong-Min Kim ◽  
Junseo Lee ◽  
Ju-Young Choi ◽  
Seung-Won Jin ◽  
Kyeong-Nam Nam ◽  
...  
Keyword(s):  
Protective Coating ◽  
Coating Thickness ◽  
Chloride Ion ◽  
The Self ◽  
Self Healing ◽  
Chloride Ion Penetration ◽  
Healing Efficiency ◽  
Sem Study ◽  
Capsule Size ◽  
Ion Penetration

Although self-healing protective coatings have been widely studied, systematic research on healing performance of the coating according to damage width has been rare. In addition, there has been rare reports of self-healing of the protective coating having damage width wider than 100 µm. In this study, self-healing performance of a microcapsule type self-healing protective coating on cement mortar was studied for the coating with damage width of 100–300 µm. The effect of capsule-loading (20 wt%, 30 wt% and 40 wt%), capsule size (65-, 102- and 135-µm-mean diameter) and coating thickness (50-, 80- and 100-µm-thick undercoating) on healing efficiency was investigated by water sorptivity test. Accelerated carbonation test, chloride ion penetration test and scanning electron microscope (SEM) study were conducted for the self-healing coating with a 300-µm-wide damage. Healing efficiency of the self-healing coating decreased with increasing damage width. As capsule-loading, capsule size or coating thickness increased, healing efficiency of the self-healing coating increased. Healing efficiency of 76% or higher was achieved using the self-healing coating with a 300-µm-wide scratch. The self-healing coating with a 200-µm-wide crack showed healing efficiency of 70% or higher. The self-healing coating having a 300-µm-wide scratch showed effective protection of the substrate mortar from carbonation and chloride ion penetration, which was supported by SEM study.

scholarly journals Self-Healable Supramolecular Vanadium Pentoxide Reinforced Polydimethylsiloxane-Graft-Polyurethane Composites

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 41 ◽  
Author(s):  
Ali Berkem ◽  
Ahmet Capoglu ◽  
Turgut Nugay ◽  
Erol Sancaktar ◽  
Ilke Anac
Keyword(s):  
Tensile Strength ◽  
Vanadium Pentoxide ◽  
Coupling Reaction ◽  
Optical Microscope ◽  
Mechanical Tests ◽  
Healing Time ◽  
The Self ◽  
Supramolecular Polymer ◽  
Self Healing ◽  
Healing Efficiency

The self-healing ability can be imparted to the polymers by different mechanisms. In this study, self-healing polydimethylsiloxane-graft-polyurethane (PDMS-g-PUR)/Vanadium pentoxide (V2O5) nanofiber supramolecular polymer composites based on a reversible hydrogen bonding mechanism are prepared. V2O5 nanofibers are synthesized via colloidal route and characterized by XRD, SEM, EDX, and TEM techniques. In order to prepare PDMS-g-PUR, linear aliphatic PUR having one –COOH functional group (PUR-COOH) is synthesized and grafted onto aminopropyl functionalized PDMS by EDC/HCl coupling reaction. PUR-COOH and PDMS-g-PUR are characterized by 1H NMR, FTIR. PDMS-g-PUR/V2O5 nanofiber composites are prepared and characterized by DSC/TGA, FTIR, and tensile tests. The self-healing ability of PDMS-graft-PUR and composites are determined by mechanical tests and optical microscope. Tensile strength data obtained from mechanical tests show that healing efficiencies of PDMS-g-PUR increase with healing time and reach 85.4 ± 1.2 % after waiting 120 min at 50 °C. The addition of V2O5 nanofibers enhances the mechanical properties and healing efficiency of the PDMS-g-PUR. An increase of healing efficiency and max tensile strength from 85.4 ± 1.2% to 95.3 ± 0.4% and 113.08 ± 5.24 kPa to 1443.40 ± 8.96 kPa is observed after the addition of 10 wt % V2O5 nanofiber into the polymer.

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