scholarly journals Influence of the Prepolymer Type and Synthesis Parameters on Self-Healing Anticorrosion Properties of Composite Coatings Containing Isophorone Diisocyanate-Loaded Polyurethane Microcapsules

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 840
Author(s):  
Matic Šobak ◽  
Danaja Štular ◽  
Žiga Štirn ◽  
Gregor Žitko ◽  
Nataša Čelan Korošin ◽  
...  

Self-healing anticorrosion composite coatings containing isophorone diisocyanate-loaded polyurethane microcapsules were developed, and comprehensive research on prepolymer and microcapsules synthesis, as well as functional composite coatings preparation and characterization, was performed. The influence of the prepolymer type and the concentration of the stabilizing agent used in the synthesis procedure on the properties of the microcapsules was studied in detail. For this purpose, three different prepolymers were prepared from toluene-2,4-diisocyanate (TDI) and either glycerol, 1,4-butanediol, or 1,6-hexanediol, and their chemical properties were investigated. Microcapsules were synthesized from the obtained prepolymers, according to the oil-in-water polymerization method, where 1,6-hexanediol was used as a chain extender, while the concentration of the stabilizing agent in the synthesis procedure was varied. Microcapsules prepared from TDI-glycerol prepolymer, synthesized in the presence of 10 wt% of the stabilizing agent, showed superior chemical, morphological, and thermo-gravimetrical properties; thus, they were incorporated into the coating in the concentration of 20 wt%. The prepared composite coatings demonstrated self-healing and anticorrosion properties, and thus the developed microcapsules show great potential for the incorporation into the composite anticorrosion coatings at critical points where damage can easily occur, providing longer and more efficient anticorrosion protection.

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 704
Author(s):  
Marija Riđošić ◽  
Nebojša D. Nikolić ◽  
Asier Salicio-Paz ◽  
Eva García-Lecina ◽  
Ljiljana S. Živković ◽  
...  

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.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Seyedalireza Mortazavi Tabrizi ◽  
Afshin Javadi ◽  
Navideh Anarjan ◽  
Seyyed Javid Mortazavi Tabrizi ◽  
Hamid Mirzaei

AbstractGarlic oil in water nanoemulsion was resulted through subcritical water method (temperature of 120 °C and pressure of 1.5 bar, for 2 h), using aponin, as emulsifier. Based on the prepared garlic oil nanoemulsion, astaxanthin–garlic oil nanoemulsions were prepared using spontaneous microemulsification technique. Response surface methodology was employed to evaluate the effects of independent variables namely, amount of garlic oil nanoemulsion (1–9 mL) and amount of provided astaxanthin powder (1–9 g) on particle size and polydispersity index (PDI) of the resulted nanoemulsions. Results of optimization indicated that well dispersed and spherical nanodroplets were formed in the nanoemulsions with minimum particle size (76 nm) and polydispersity index (PDI, 0.358) and maximum zeta potential value (−8.01 mV), using garlic oil nanoemulsion amount of 8.27 mL and 4.15 g of astaxanthin powder. Strong antioxidant activity (>100%) of the prepared astaxanthin–garlic oil nanoemulsion, using obtained optimum amounts of the components, could be related to the highest antioxidant activity of the colloidal astaxanthin (>100%) as compared to that of the garlic oil nanoemulsion (16.4%). However, higher bactericidal activity of the resulted nanoemulsion against Escherichia coli and Staphylococcus aureus, were related to the main sulfur bioactive components of the garlic oil in which their main functional groups were detected by Fourier transform-infrared spectroscopy.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Ashraf Farshbaf-Sadigh ◽  
Hoda Jafarizadeh-Malmiri ◽  
Navideh Anarjan ◽  
Yahya Najian

Abstract Ginger oil in water (O/W) nanoemulsions, were produced using phase inversion composition method and Tween 80, as emulsifier. Effects of processing parameters namely, stirring rate (100 to1000 rpm) and water addition rate (1–10 mL/min) were evaluated on the physico-chemical, morphological, antioxidant and antimicrobial properties of the prepared O/W nanoemulsions using response surface methodology (RSM). Results indicated that well dispersed and spherical ginger nanodroplets were formed in the nanoemulsions with minimum particle size (8.80 nm) and polydispersity index (PDI, 0.285) and maximum zeta potential value (−9.15 mV), using stirring rate and water addition rate of 736 rpm and 8.18 mL/min, respectively. Insignificant differences between predicted and experimental values of the response variables, indicated suitability of fitted models using RSM. Mean particle size of the prepared nanoemulsion using optimum conditions were changed from 8.81 ± 1 to 9.80 ± 1 nm, during 4 weeks of storage, which revealed high stability of the resulted ginger O/W nanoemulsion. High antioxidant activity (55.4%), bactericidal (against Streptococcus mutans) and fungicidal (against Aspergillus niger) activities of the prepared nanoemulsion could be related to the presence of gingerols and shogaols, a group of phenolic alkanones, in the ginger oil, which those were detected by gas chromatography method.


2019 ◽  
Vol 129 ◽  
pp. 285-291 ◽  
Author(s):  
Jing Li ◽  
Zhenwei Li ◽  
Qingkang Feng ◽  
Hanxun Qiu ◽  
Guangzhi Yang ◽  
...  

Author(s):  
Muddasir Nawaz ◽  
Sehrish Habib ◽  
Adnan Khan ◽  
Abdul Shakoor ◽  
Ramazan Kahraman

The use of organic coating for the metals has been widely being used to protect the surface against corrosion. Polymeric coating incorporated with Nanocontainers loaded with inhibitor and self-healing provides better corrosion resistance. Cellulose microfibers (CMFs) used as smart carriers were synthesized and loaded with dodecylamine (DOC)-inhibitor and polyethyleneimine (PEI)-both inhibitor and self-healing agents. Smart polymeric coatings were developed by mixing CMF/DOC and CMFs/PEI into the epoxy matrix. Reference coatings (that has only CMFs) were also prepared for a compersion. Scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal gravitational analysis (TGA) were used to confirm the loading of DOC and PEI onto the CMFs. UV-vis analysis indicates that the self-release of inhibitor from CMFs is sensitive to pH of the solution and the immersion time. Recovery of controlled surface damage confirms the decent self-healing ability of the prepared smart coatings is due to the efficient release of inhibitor (DOC) and self-healing agent (PEI) in the damaged area leading to the formation of a protective film. Electrochemical impedance spectroscopy (EIS) results demonstrate that corrosion resistance of the smart coating increases with an increase in immersion time which is due to the progressive release of inhibitors from CMFs in response to the pH change. Therefore, smart coatings demonstrate superior properties as compared to the reference coatings. The study reveals the polymeric composite coatings have potential to inhibit the corrosion of steel for oil and gas industry.


2015 ◽  
Vol 245 ◽  
pp. 89-96 ◽  
Author(s):  
Andrey S. Gnedenkov ◽  
Sergey L. Sinebryukhov ◽  
Dmitry V. Mashtalyar ◽  
Sergey V. Gnedenkov

The way of self-healing coating formation at the surface of magnesium alloys by means of plasma electrolytic oxidation method (PEO) with subsequent filling of the obtained layer with inhibitor has been suggested. The electrochemical properties of such coatings have been described in details. The obtained experimental results indicate that the protective properties of the samples with inhibitor-containing coating were increased (IC = 8.6×10–8 A/cm2) in comparison with the samples without coating (5.3×10–5 A/cm2) and the base coating obtained by plasma electrolytic oxidation method (PEO) (3.4×10–7 A/cm2). The local scanning electrochemical methods of surface investigation, notably Scanning Vibrating Electrode Technique (SVET) and Scanning Ion-Selective Electrode Technique (SIET) were used for determining the kinetics and mechanism of the self-healing process. The treatment by the solution containing 8-hydroxyquinoline, which inhibits the corrosion process, enables one to increase the protective properties of the composite coating in 30 times in the corrosion-active environment in comparison with the base PEO-coating and avert the intensive destruction of the material.


2019 ◽  
Vol 10 (7) ◽  
pp. 885-890 ◽  
Author(s):  
Haiyang Yong ◽  
Yongpeng Miao ◽  
Sigen A ◽  
Dong Quan ◽  
Alojz Ivankovic ◽  
...  

Branched polymers exhibit a unique three-dimensional (3D) molecular architecture and distinctive physical/chemical properties, and thus have been applied in a wide variety of fields.


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