An electrochemical study of corrosion protection by in situ oxidative polymerization in phenylenediamine crosslinked sol–gel hybrid coatings

2011 ◽  
Vol 56 (23) ◽  
pp. 7796-7804 ◽  
Author(s):  
Kenneth J. Croes ◽  
Andrew J. Vreugdenhil ◽  
Maocheng Yan ◽  
Thomas A. Singleton ◽  
Samuel Boraas ◽  
...  
2012 ◽  
Vol 70 (3) ◽  
pp. 1037-1048 ◽  
Author(s):  
Emrah Çakmakçı ◽  
Yusuf Mülazim ◽  
Memet Vezir Kahraman

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5382
Author(s):  
Guillaume Lollivier ◽  
Marie Gressier ◽  
Florence Ansart ◽  
Maëlenn Aufray ◽  
Marie-Joëlle Menu

Self-healing polymers are a new class of material that has recently received a lot of attention because of the lifespan improvement it could bring to multiple applications. One of the major challenges is to obtain multifunctional materials which can self-heal and exhibit other interesting properties such as protection against corrosion. In this paper, the effect of the incorporation of an aminosilane on the properties of a self-healing organic polymer containing disulfide bond is studied on films and coatings for aluminium AA2024-T3 using simple one step in situ synthesis. Hybrid coatings with enhanced anticorrosion properties measured by EIS were obtained thanks to the formation of a protective oxide interface layer, while exhibiting wound closure after exposition at 75 °C. The thermal, mechanical and rheological properties of the films with different aminosilane amounts were characterized in order to understand the influence of the slight presence of the inorganic network. Stiffer and reprocessable hybrid films were obtained, capable to recover their mechanical properties after healing. The nanocomposite structure, confirmed by TEM, had a positive effect on the self-healing and stress relaxation properties. These results highlight the potential of sol-gel chemistry to obtain efficient anticorrosion and self-healing coatings.


2020 ◽  
Vol 20 (3) ◽  
pp. 1756-1764 ◽  
Author(s):  
Peng Chen ◽  
Lin-Wen Jiang ◽  
Shan-Shan Yang ◽  
Hong-Bing Chen ◽  
Jun He ◽  
...  

Organic–inorganic CoFe2O4/polyaniline (CoFe2O4/PA) nanocomposites with embedded structures were synthesized by combining the sol–gel auto-combustion process and in-situ oxidative polymerization. The phases and morphologies of the prepared samples were identified. The pure CoFe2O4 samples exhibited inferior microwave-absorption properties in a frequency range of 2–18 GHz. Upon the incorporation of PA, the formed CoFe2O4/PA nanocomposites exhibited rather good absorption performances. When the sample thickness was 2.5 mm, the maximum reflection loss (RL) reached -22.3 dB, while the RL below -10 dB corresponded to the range of 11.0–17.1 GHz, which contains almost the entire Ku-band, making the structure promising for commercial and military applications. A physical model was employed to explain the effects of the embedded structure on the microwave-absorption performances. The excellent microwave-absorption performances could be attributed to the interfacial polarization and repeated reflection of the microwaves inside the CoFe2O4/PA composite.


2009 ◽  
Vol 2 (1) ◽  
pp. 197-203 ◽  
Author(s):  
G. Carbajal-de la Torre ◽  
M. A. Espinosa-Medina ◽  
A. Martinez-Villafane ◽  
J. G. Gonzalez-Rodriguez ◽  
V. M. Castano

2008 ◽  
Vol 8 (6) ◽  
pp. 3040-3049 ◽  
Author(s):  
Kung-Chin Chang ◽  
Hui-Fen Lin ◽  
Chang-Yu Lin ◽  
Tai-Hung Kuo ◽  
Hsin-Hua Huang ◽  
...  

In this paper, a series of organic–inorganic hybrid materials consisting of epoxy resin frameworks and dispersed nanoparticles of amino-modified silica (AMS) were successfully prepared. First of all, the AMS nanoparticles were synthesized by carrying out the conventional acid-catalyzed sol–gel reactions of tetraethyl orthosilicate (TEOS) in the presence of (3-aminopropyl)-trimethoxysilane (APTES) molecules. The as-prepared AMS nanoparticles were then characterized by FTIR, 13C-NMR and 29Si-NMR spectroscopy. Subsequently, a series of hybrid materials were prepared by performing in-situ thermal ring-opening polymerization reactions of epoxy resin in the presence of as-prepared AMS nanoparticles and raw silica (RS) particles. The as-prepared epoxy-silica hybrid materials with AMS nanoparticles were found to show better dispersion capability than that of RS particles existed in hybrid materials based on the morphological observation of transmission electron microscopy (TEM). The hybrid materials containing AMS nanoparticles in the form of coating on cold-rolled steel (CRS) were found to be much superior in corrosion protection over those of hybrid materials with RS particles when tested by a series of electrochemical measurements of potentiodynamic and impedance spectroscopy in 5 wt% aqueous NaCl electrolyte. The increase of corrosion protection effect of hybrid coatings may have probably resulted from the enhancement of the adhesion strength of the hybrid coatings on CRS coupons, which may be attributed to the formation of Fe—O—Si covalent bond at the interface of coating/CRS system based on the FTIR-RAS (reflection absorption spectroscopy) studies. The better dispersion capability of AMS nanoparticles in hybrid materials were found to lead more effectively enhanced molecular barrier property, mechanical strength, surface hydrophobicity and optical clarity as compared to that of RS particles, in the form of coating and membrane, based on the measurements of molecular permeability analysis, dynamic mechanical analysis, contact angle measurements and ultraviolet-visible transmission spectra, respectively.


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