Self-Healing Epoxy Coating Modified by Double-Walled Microcapsules Based Polyurea for Metallic Protection

2019 ◽  
Vol 821 ◽  
pp. 313-320
Author(s):  
Yan Xuan Ma ◽  
Ying Rui Zhang ◽  
Jia Tong Liu ◽  
Meng Yao Li ◽  
Ya Qian Xu
Keyword(s):  
Chemical Structure ◽  
Interfacial Polymerization ◽  
Electrochemical Impedance ◽  
Self Healing ◽  
High Corrosion Resistance ◽  
Hexamethylene Diamine ◽  
Thermogravimetric Analyzer ◽  
The Core ◽  
Core Content ◽  
Scanning Electronmicroscopy

The effectiveness of preploymer and 1,6-Hexamethylene diamine encapsulated by double-walled microcapsules based polyurea (PUA) was explored for healing the cracks generated in epoxy coatings. Double-walled microcapsules were systhesized by interfacial polymerization at the interface between the prepolymer droplets and the 1,6-Hexamethylene diamine droplets to form the polyurea shell. The effect of synthetic stirring speed on the morphology of the microcapsules was observed by scanning electronmicroscopy (SEM) and optical microscopy (OM). The chemical structure as well as the thermal properties and the core content were characterized by Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric analyzer (TGA) respectively. Electrochemical impedance spectroscopy (EIS) studies of the artificial scratched area showed that the coating containing 2wt% and 5wt% microcapsules could effectively prevent further corrosion of the coating with high corrosion resistance efficiencies of 61.61% and 45.99% after immersing for 144h in seawater.

Synthesis and Self-Healing Mechanism of Self-Healing Epoxy Microcapsule Materials

2020 ◽  
Vol 842 ◽  
pp. 3-9
Author(s):  
Zhuo Ni ◽  
Zhen Guo ◽  
Yu Hao Lin
Keyword(s):  
Epoxy Resin ◽  
Interfacial Polymerization ◽  
Curing Temperature ◽  
Future Research ◽  
Self Healing ◽  
Practical Applications ◽  
The Core ◽  
Good Surface ◽  
Core Content ◽  
Wall Materials

Self-healing epoxy resin microcapsules are prepared by interfacial polymerization, in which the core materials are epoxy resin, the wall materials are constructed with triethylenetetramine and the epoxy resin. The orthogonal experimental L9(34) are designed to investigate the influence of emulsifier dosage, hardener dosage, curing temperature and hardener adding rate on the core content and storage life of epoxy resin microcapsule. Scanning electron microscope is used to characterize surface topography and distribution. Fourier transform infrared spectroscopy is used to study reaction mechanism of the microcapsule wall materials, respectively. The results indicate that when the dosage of emulsifier is 1.2%, the dosage of hardener is 1.2%, the hardener droplets adding rate is 1.2 g/h and the curing temperature is 50°C, the prepared microcapsules with a high level of core content are spherical in shape with good surface compactness and dispersibility. Future research may focus on improving microcapsule storage stability and the obstacles encountered in practical applications.

scholarly journals SYNTHESIS OF MICROCAPSULES FROM PREPOLYURETHANES

2018 ◽  
Vol 55 (1B) ◽  
pp. 138
Author(s):  
Ha La Thi Thai
Keyword(s):  
Interfacial Polymerization ◽  
Gum Arabic ◽  
Chain Extender ◽  
Toluene Diisocyanate ◽  
Agitation Rate ◽  
Self Healing ◽  
The Core ◽  
Core Content ◽  
Oil In Water ◽  
Healing Agent

Polyurethane (PU) microcapsules containing toluene diisocyanate (TDI) healing agent were synthesized by mixing PU with chain extender ethyleneglycol (EG) via interfacial polymerization of oil–in–water (gum arabic emulsifier). The morphology and size of the capsules greatly depend on a variety of factors including dispersion speed and emulsifier ratio. The preparation of PU prepolymer and microcapsulation of TDI are presented. The diameter of smooth spherical microcapsules ranged from 93, 160 and 239 µm are produced by varying the agitation rate from 800 rpm to 1200 rpm. The core content of microcapsules is influenced by the ratio of chlorobenzene (CB) solvent in oil phase. The microcapsules have about 40.5 wt% of core which are capable of application in self–healing coatings when using 20 wt% CB and 17.5 wt% emulsifer ratio.

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.

Comparative Study on Microencapsulated of Natural and Waste Sunflower Oil as Self-Healing Agent

2020 ◽  
Vol 1010 ◽  
pp. 439-444
Author(s):  
Zulkhibri Baharom ◽  
Maizlinda Izwana Idris ◽  
Tee Chuan Lee ◽  
Hasan Zuhudi Abdullah
Keyword(s):  
Sunflower Oil ◽  
Raw Materials ◽  
Metal Coating ◽  
Natural Material ◽  
Self Healing ◽  
Micro Structure ◽  
The Core ◽  
Core Content ◽  
Healing Agent ◽  
Alternative Resource

Microencapsulation of natural vegetable oil as a self-healing agent on metal coating became demanded lately. This paper underlines the microcapsule containing natural and wastes sunflower oil as a self-healing agent that was fabricated for the backbone of corrosion coatings. The results in this paper indicated the distinguished potential of waste sunflower oil as compared to natural sunflower oil. The diameter of microcapsules synthesized from natural sunflower oil and waste sunflower oil both in range of 3-4 µm. The shell of microcapsules microencapsulated from natural sunflower oil showed rough micro-structure while the shell of microcapsules microencapsulated from waste sunflower oil showed smooth micro-structure. The main parameter studied in this research was the varient of stirring speed during the process of microencapsulation. The involvement of stirring speed starts from 200 to 400 rpm. The microcapsules undergo varient of stirring speed analyzed on the yield and core content of microcapsules. The microcapsules from natural produced 29-50% while waste resources bring 26-48% of yield productions. The core content of microencapsulated natural sunflower oil generates 55-64% core content as comparing with waste sources which produce 56-67% of core content. It can be concluded that it was proved that sunflower oil could be considered as an alternative resource for self-healing agent in metal coating either encapsulated from natural or waste raw materials. The incorporation of green and natural material as a self-healing agent significantly influences the sustaining the environment to the safest stage.

scholarly journals Preparation and Characterization of Nano-CaCO3/Ceresine Wax Composite Shell Microcapsules Containing E-44 Epoxy Resin for Self-Healing of Cement-Based Materials

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 197
Author(s):  
Wei Du ◽  
Erwang Li ◽  
Runsheng Lin
Keyword(s):  
Epoxy Resin ◽  
Recovery Rate ◽  
Composite Shell ◽  
Chloride Ion ◽  
Self Healing ◽  
The Core ◽  
Core Content ◽  
Cement Based Materials ◽  
Healing Agent ◽  
Melt Condensation

As an intelligent material, microcapsules can efficiently self-heal internal microcracks and microdefects formed in cement-based materials during service and improve their durability. In this paper, microcapsules of nano-CaCO3/ceresine wax composite shell encapsulated with E-44 epoxy resin were prepared via the melt condensation method. The core content, compactness, particle size distribution, morphologies, chemical structure and micromechanical properties of microcapsules were characterized. The results showed that the encapsulation ability, mechanical properties and compactness of microcapsules were further improved by adding nano-CaCO3 to ceresine wax. The core content, elastic modulus, hardness and weight loss rate (60 days) of nano-CaCO3/ceresine wax composite shell microcapsules (WM2) were 80.6%, 2.02 GPA, 72.54 MPa and 1.6%, respectively. SEM showed that WM2 was regularly spherical with a rough surface and sufficient space inside the microcapsules to store the healing agent. The incorporation of WM2 to mortar can greatly improve the self-healing ability of mortar after pre-damage. After 14 days of self-healing, the compressive strength recovery rate, proportion of harmful pores and chloride ion diffusion coefficient recovery rate increased to 90.1%, 45.54% and 79.8%, respectively. In addition, WM2 also has good self-healing ability for mortar surface cracks, and cracks with initial width of less than 0.35 mm on the mortar surface can completely self-heal within 3 days.

scholarly journals TO/TMMP-TMTGE Double-Healing Composite Containing a Transesterification Reversible Matrix and Tung Oil-Loaded Microcapsules for Active Self-Healing

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1127 ◽  
Author(s):  
Nan Zheng ◽  
Jie Liu ◽  
Wenge Li
Keyword(s):  
Particle Size ◽  
Click Reaction ◽  
Average Particle Size ◽  
Core Shell ◽  
Average Particle ◽  
Self Healing ◽  
Tung Oil ◽  
The Core ◽  
Core Content ◽  
Healing System

Thermoset epoxies are widely used due to their excellent properties, but conventional epoxies require a complicated and time-consuming curing process, and they cannot self-healed, which limits their applications in self-healing materials. Extrinsic and intrinsic self-healing materials are applied in various fields due to their respective characteristics, but there is a lack of comparison between the two types of healing systems. Based on this, a thiol-epoxide click reaction catalyzed by an organic base was introduced to achieve the efficient preparation of thiol-epoxy. Furthermore, tung oil (TO)-loaded microcapsules were introduced into the thiol-epoxy matrix of dynamic transesterification to obtain a TO/TMMP-TMTGE self-healing composite with an intrinsic–extrinsic double-healing system. For comparison, a TMMP-TMTGE self-healing material with an intrinsic healing system was also prepared, which contained only thiol and epoxy curing chemistries. The effect of the core/shell ratio on the morphology, average particle size, and core content of TO-loaded microcapsules was studied. It was found that when the core/shell ratio was 3:1, the average particle size of the microcapsules was about 99.8 μm, and the microcapsules showed good monodispersity, as well as a core content of about 58.91%. The differential scanning calorimetry (DSC) results showed that the TO core was successfully encapsulated and remained effective after encapsulation. Furthermore, scanning electron microscopy (SEM), atomic force microscopy (AFM), tensile tests, and electrochemical tests were carried out for the two types of self-healing materials. The results showed that the TO/TMMP-TMTGE composite and TMMP-TMTGE material both had self-healing properties. In addition, the TO/TMMP-TMTGE composite was superior to the TMMP-TMTGE material due to its better self-healing performance, mechanical strength, and corrosion protection performance.

scholarly journals Microencapsulation of Photochromic Solution with Polyurea by Interfacial Polymerization

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3049
Author(s):  
Yuhua Zhang ◽  
Xi Zhang ◽  
Yurong Yan ◽  
Zhonghua Chen
Keyword(s):  
Particle Size ◽  
Interfacial Polymerization ◽  
Uv Light ◽  
Thermogravimetric Analyzer ◽  
The Core ◽  
Oxygen Ion ◽  
Particle Size Analyzer ◽  
Photochromic Materials ◽  
Addition Amount ◽  
Uniform Particle Size

Photochromic materials are interesting materials because of their color-changing property under UV light and visible light irradiation. However, they are vulnerable to many factors, such as pH oxygen, ion, solvent, etc. because of the unsaturated bonds existing on the photochromic molecular. Microencapsulation of the photochromic materials can separate them from the surroundings. Here, photochromic microcapsules using 3,3-Diphenyl-3H-naphtho[2,1-b] pyran (NP)/solution as core and polyurea as shell via interfacial polymerization were prepared, and bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate (HALS 770) was used as photostabilizer. Fourier transform infrared spectroscopy (FTIR), a laser particle size analyzer, a scanning electron microscope (SEM), a thermogravimetric analyzer and an ultraviolet-visible spectrophotometer were used for characterization. The results showed that the microcapsules had a uniform particle size of about 0.56 μm when the percentage of the oil phase (core) in the emulsion was less than 15%, the addition amount of the emulsifier was 0.4%, and the stirring rate was 1800r/min. The microcapsules showed better performance in thermal stability when the core/shell ratio was 1:1. The photostabilizer had little impact on the color-changing property of the microcapsule, but it could protect the microcapsules from UV light radiation aging.

scholarly journals Self-healing and corrosion performance of polyurethane coating containing polyurethane microcapsules

2021 ◽  
Author(s):  
Hanieh Fathi Fathabadi ◽  
Mehdi Javidi
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Interfacial Polymerization ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
The Self ◽  
Self Healing ◽  
Polyurethane Coating ◽  
Healing Efficiency ◽  
Scanning Electron

Abstract In this study, the self-healing behavior of the polyurethane coating containing polyurethane microcapsules was investigated. Microcapsules, with the average size of 99 µm and shell thickness of 11 µm, were successfully synthesized via the interfacial polymerization technique and were incorporated into the polyurethane coating matrix. The electrochemical impedance spectroscopy and scanning electron microscope were employed to investigate the healing performance and corrosion behavior of the coatings on the carbon steel substrate. The recorded results revealed that artificial scratches were successfully healed and the coating containing 20 wt% microcapsules exhibited the best healing performance (85% healing efficiency) among all the prepared coatings. The self-healing ability of the coatings were verified via scanning electron microscope. After 24 hours, the healing efficiency attained a reasonable value of 68% during exposure to test solution. It was found that corrosion resistance and coating adhesion were significantly improved by incorporating the microcapsules into the coating.

scholarly journals Fabrication and Property Regulation of Small-Size Polyamine Microcapsules via Integrating Microfluidic T-Junction and Interfacial Polymerization

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1800
Author(s):  
Shaochuan Lai ◽  
Yongjun He ◽  
Daoying Xiong ◽  
Yao Wang ◽  
Kaibin Xiao ◽  
...  
Keyword(s):  
Interfacial Polymerization ◽  
Monomer Concentration ◽  
The Self ◽  
Self Healing ◽  
Core Content ◽  
Epoxy Amine ◽  
Healing System ◽  
Application Potential ◽  
Size Restriction ◽  
Shell Forming

The self-healing system based on microencapsulated epoxy-amine chemistry is currently the self-healing system with the most practical application potential. It can be widely used in many epoxy-based materials with a size restriction for the microcapsules, such as fiber-reinforced composites, anti-corrosion coatings, etc. Although epoxy microcapsules of different sizes can be fabricated using different techniques, the preparation of polyamine microcapsules with suitable sizes and good performance is the prerequisite for further developing this self-healing system. In this investigation, based on the novel microencapsulation technique via integrating microfluidic T-junction and interfacial polymerization, the feasibility of preparing small-size polyamine microcapsules and the process regulation to optimize the properties of the small-size microcapsules were studied. We show that polyamine microcapsules with sizes smaller than 100 μm can be obtained through the T-junction selection and the feeding rate control of the polyamine. To regulate the small-size microcapsules’ quality, the effects of the concentration of the shell-forming monomer and the solvent with different polarity in the reaction solution and the reaction condition were studied. It shows that dry, free-flowing small-size microcapsules can still be obtained when the shell-forming monomer concentration is higher and the solvent’s polarity is lower, compared with the preparation of larger polyamine microcapsules. Although the change of reaction conditions (reaction temperature and duration) has a certain effect on the microcapsules’ effective core content, it is relatively small. The results of this investigation further promote the potential application of the self-healing systems based on microencapsulated epoxy-amine chemistry in materials with a size restriction for the microcapsules.

scholarly journals Zn-Co-CeO2 vs. Zn-Co Coatings: Effect of CeO2 Sol in the Enhancement of the Corrosion Performance of Electrodeposited Composite Coatings

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 704
Author(s):  
Marija Riđošić ◽  
Nebojša D. Nikolić ◽  
Asier Salicio-Paz ◽  
Eva García-Lecina ◽  
Ljiljana S. Živković ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Healing Rate ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Self Healing ◽  
Kelvin Probe ◽  
Artificial Defect ◽  
Volta Potential ◽  
Superior Corrosion Resistance ◽  
The Stability

Electrodeposition and characterization of novel ceria-doped Zn-Co composite coatings was the main goal of this research. Electrodeposited composite coatings were compared to pure Zn-Co coatings obtained under the same conditions. The effect of two ceria sources, powder and home-made sol, on the morphology and corrosion resistance of the composite coatings was determined. During the electrodeposition process the plating solution was successfully agitated in an ultrasound bath. The source of the particles was found to influence the stability and dispersity of plating solutions. The application of ceria sol resulted in an increase of the ceria content in the resulting coating and favored the refinement from cauliflower-like morphology (Zn-Co) to uniform and compact coral-like structure (Zn-Co-CeO2 sol). The corrosion resistance of the composite coatings was enhanced compared to bare Zn-Co as evidenced by electrochemical impedance spectroscopy and scanning Kelvin probe results. Zn-Co doped with ceria particles originating from ceria sol exhibited superior corrosion resistance compared to Zn-Co-CeO2 (powder) coatings. The self-healing rate of artificial defect was calculated based on measured Volta potential difference for which Zn-Co-CeO2 (sol) coatings exhibited a self-healing rate of 73.28% in a chloride-rich environment.

Sign in / Sign up

Export Citation Format

Share Document