Barrier properties of high performance PMMA-silica anticorrosion coatings

Trentin, Andressa; Gasparini, Andressa de L.; Faria, Flávio A.; Harb, Samarah Vargas; Santos, F. C. dos; Pulcinelli, Sandra Helena; Santilli, Celso Valentim; Hammer, Peter

doi:10.1016/j.porgcoat.2019.105398

Cited by 34 publications

(56 citation statements)

References 33 publications

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“…Starting from high frequencies, the value of |Z| increases linearly with decreasing frequency and, for both coatings, reaches extremely high values in the low frequency region, i.e., up to 5 GΩ cm 2 at 4 mHz; the same value of uncoated metal is almost six orders of magnitude smaller. Value of impedance at 4 mHz was chosen as the parameter representing the corrosion resistance of the coating due to corrosion processes at the inner interface with the substrate [8]. Bode plots of Φ vs. f are similar for the two coated substrates in the region from 10 5 to 1 Hz, showing pure capacitive behaviour with phase angles of almost −90 • .…”

Section: Electrochemical Propertiesmentioning

confidence: 99%

“…The CPE 1 and R po are related to the high frequency (f ) region corresponding to the coating/electrolyte interface; in other words, these parameters correspond to the coating resistance to water uptake at the outer interface resulting from the formation of ionically conducting paths across the coating (also referred to as pore resistance). The CPE 2 and R 2 are related to the low frequency region corresponding to the response of the inner layer adjacent to the metal/coating interface [8,11,14]. Fitted parameters including Q as the pseudocapacitance of CPE, R as the resistance and n as the CPE power are presented in Table 5.…”

Section: Electrochemical Propertiesmentioning

confidence: 99%

“…The resulting transparent coatings have, after six months in 3.5% NaCl, yielded the best corrosion performances with impedance values of around 10 GΩ cm 2 at frequency of 10 mHz [6]. By increasing the ratio between thermal initiator benzoyl peroxide (BPO) and MMA, the polymerization efficiency can be improved [8]. Some sol-gel coatings were doped in order to increase their cross-linking, increase adhesion to the metal substrate, or to improve scratch resistance and thermal stability [7,[9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

“…Hybrid sols have been prepared using TEOS and MAPTMS in the optimum ratio [5]. Since previous studies on these type of coatings were carried out on steel-based substrates [3][4][5][6] and less on Al-based substrate [8,15], we focused this study on aluminium alloy (AA) 7075-T6 substrate. This particular alloy was chosen because it is the least corrosion resistant among alloys used in the aviation industry.…”

Section: Introductionmentioning

confidence: 99%

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The Effect of the Methyl and Ethyl Group of the Acrylate Precursor in Hybrid Silane Coatings Used for Corrosion Protection of Aluminium Alloy 7075-T6

et al. 2020

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This study investigated polysiloxane hybrid sol-gel coatings synthesized from tetraethyl orthosilicate (TEOS), 3-(trimethoxysilyl)propyl methacrylate (MAPTMS) and two different precursors, i.e., methyl- or ethyl- methacrylate (MMA or EMA), as corrosion protection of aluminium alloy 7075-T6. The hypothesis was that the additional alkyl group might affect the chemical properties and, consequently, the corrosion properties. Synthesis of the sols proceeded in two steps, each involving either MMA or EMA in the same molar ratio. The resulting sols, siloxane-(poly(methyl methacrylate-co-MAPTMS)) or siloxane-(poly(ethyl methacrylate-co-MAPTMS)), were applied on aluminium alloy followed by characterization in terms of chemical structure and composition, topography, wettability, adhesion and corrosion resistance in 0.1 M sodium chloride solution. The chemical properties of sols, monoliths and coatings were investigated using Fourier transform infrared spectrometry, solid state nuclear magnetic resonance spectrometry, X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. Coatings were similar in terms of surface topography, while the wettability of the coating with EMA showed 6° greater water contact angle compared to the coating with MMA. Both coatings were shown, by electrochemical impedance spectroscopy in 0.1 M NaCl solution, to act as barriers to protect the underlying substrate in which coating with EMA exhibits better protection properties after 2 months of immersion. Adhesion tests confirmed the highest grade of adhesion to the substrate for both coatings. Testing in a salt-spray chamber demonstrated excellent corrosion protection, where coatings remaining intact after more than 600 h of exposure.

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Section: Electrochemical Propertiesmentioning

confidence: 99%

Section: Electrochemical Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Effect of the Methyl and Ethyl Group of the Acrylate Precursor in Hybrid Silane Coatings Used for Corrosion Protection of Aluminium Alloy 7075-T6

et al. 2020

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“…These hybrid materials have demonstrated excellent barrier property, providing long-term protection for steel and aluminum alloys [3,[8][9][10]. The superiority of hybrid systems compared to purely polymeric phases comes from a tailored nanostructure achieved by proper amounts of inorganic nanofillers within the organic matrix and the careful tuning of synthesis conditions, resulting in a dense and homogeneous nanocomposite that acts as an efficient diffusion barrier, limiting the water uptake and diffusion of ionic species to a very low rate [11]. The inorganic nodes have the important role to densify the structure by anchoring covalently the polymeric chain segments through a cross-linking agent and to improve the adhesion at the coating/metal interface through covalent bonding [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Organic-Inorganic Hybrid Coatings for Active and Passive Corrosion Protection

Trentin¹,

Harb²,

Souza³

et al. 2020

Corrosion [Working Title]

Self Cite

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Organic-inorganic coatings based on poly(methyl methacrylate) (PMMA)-silica and PMMA-cerium oxide hybrids provide effective and active corrosion protection of metallic surfaces. For both hybrid materials, the covalent conjugation of inorganic silica or ceria nanodomains with the PMMA matrix, provided by molecular coupling agents, leads to homogenous and highly cross-linked nanocomposites, which act in the form of coatings as an efficient diffusion barrier. The addition of lithium salts (500-2000 ppm) into PMMA-silica hybrid and optimized ceria fraction in PMMA-cerium oxide coatings results in active corrosion inhibition by the self-healing effect. Results of electrochemical assays of aluminum-and steel-coated samples, performed in a 3.5% NaCl solution, show an excellent corrosion resistance (impedance modulus up to 100 GΩ cm 2) and durability (up to 350 days) of the 10-μm-thick passive barrier layer. Time-of-flight secondary ion mass and X-ray photoelectron spectroscopies evidenced the self-healing ability of coatings induced by lithium/cerium ion leaching toward corrosion spots or artificial scratches, which are restored by a protective layer of precipitated phases. Results presented in this book chapter evidence the active role of lithium and cerium species in improving the hybrid structure and providing through self-healing a significantly extended service life of metallic components.

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Fabrication of multifunctional polymethyl methacrylate composites based on phosphorus‐containing polyaniline with excellent flame retardancy and electrical conductivity

Zhan

Wang

Zhang

et al. 2020

Polymers for Advanced Techs

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After the incorporation of the polyaniline (PANI), polymethyl methacrylate (PMMA) composites with outstanding electrical conductivity had been widely used in sensors. However, the flame retardancy of PMMA composites seriously restrained its further application. Thus, phosphorus‐containing polyaniline (FR‐PANI) was successfully prepared and combined with PMMA. The flame retardancy, electrical conductivity, thermal stability, and fire behavior of the resultant PMMA/FR‐PANI composites were systematically studied. When the loading amount of FR‐PANI was controlled at 20 wt%, the PMMA matrix was endowed with dramatic flame retardancy, exhibiting a limiting oxygen index of 29.1% and a UL‐94 V‐0 rating in vertical burning tests. Meanwhile, the volume resistivity was also reduced up to 0.5 MΩ. The thermal stability of the PMMA/FR‐PANI composites was enhanced by the formation of abundant char residue, which improved the fire behavior of the PMMA matrix. The effect of FR‐PANI on the flame retardancy of the PMMA matrix was deduced on the basis of thermogravimetry‐infrared, Fourier transform infrared, and scanning electron microscopic analyses. The phosphorus‐containing functional groups in the FR‐PANI molecular chain underwent thermal degradation in the condensed phase and promoted the formation of a char layer. The char layer, in turn, prevented heat transfer into the interior of the PMMA composites, serving as a barrier to the volatilization of flammable micromolecules. Therefore, FR‐PANI is an important candidate to extend the range of applications of PMMA to include multifunctional intelligent sensors.

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Barrier properties of high performance PMMA-silica anticorrosion coatings

Cited by 34 publications

References 33 publications

The Effect of the Methyl and Ethyl Group of the Acrylate Precursor in Hybrid Silane Coatings Used for Corrosion Protection of Aluminium Alloy 7075-T6

The Effect of the Methyl and Ethyl Group of the Acrylate Precursor in Hybrid Silane Coatings Used for Corrosion Protection of Aluminium Alloy 7075-T6

Organic-Inorganic Hybrid Coatings for Active and Passive Corrosion Protection

Fabrication of multifunctional polymethyl methacrylate composites based on phosphorus‐containing polyaniline with excellent flame retardancy and electrical conductivity

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