Synthesis, characterization and corrosion protection properties of polyN-(p-bromophenyl)-2-methacrylamide-co-glycidyl methacrylate on low nickel stainless steel

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Sakvai Mohammed Safiullah ◽  
Deivasigamani Thirumoolan ◽  
Kottur Anver Basha ◽  
K. Mani Govindaraju ◽  
Dhanraj Gopi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Protection ◽  
Glycidyl Methacrylate ◽  
Electrochemical Impedance ◽  
Thermo Gravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Protection Efficiency ◽  
Ft Ir

Abstract The synthesis of copolymers from different feed ratios of N-(p-bromophenyl)-2- methacrylamide (PBPMA) and glycidyl methacrylate (GMA) was achieved by using free radical solution polymerization technique and characterized using FT-IR, 1H and 13C NMR spectroscopy. The thermal stability of the synthesized copolymers was studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the copolymer is determined by gel permeation chromatography (GPC). The corrosion performances of low nickel stainless steel specimens dip coated with different composition of copolymers were investigated in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the low nickel stainless steel surfaces. However, it is observed that the mole ratio of PBPMA and GMA plays a major role in the protective nature of the copolymer.

scholarly journals Acrylate-Based Hybrid Sol-Gel Coating for Corrosion Protection of AA7075-T6 in Aircraft Applications: The Effect of Copolymerization Time

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 948 ◽  
Author(s):  
Peter Rodič ◽  
Romana Cerc Korošec ◽  
Barbara Kapun ◽  
Alenka Mertelj ◽  
Ingrid Milošev
Keyword(s):  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Condensation Reaction ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Gel Permeation Chromatography ◽  
Corrosion Attack ◽  
Scanning Calorimetry ◽  
Corrosion Properties ◽  
Pressure Differential Scanning Calorimetry

Pre-hydrolysed/condensed tetraethyl orthosilicate (TEOS) was added to a solution of methyl methacrylate (MMA) and 3-methacryloxypropyltrimethoxysilane (MAPTMS), and then copolymerised for various times to study the influence of the latter on the structure of hybrid sol-gel coatings as corrosion protection of aluminium alloy 7075-T6. The reactions taking place during preparation were characterised using real-time Fourier transform infrared spectroscopy, dynamic light scattering and gel permeation chromatography. The solution characteristics were evaluated, using viscosimetry, followed by measurements of thermal stability determined by thermogravimetric analysis. The optimal temperature for the condensation reaction was determined with the help of high-pressure differential scanning calorimetry. Once deposited on 7075-T6 substrates, the coatings were evaluated using a field emission scanning electron microscope coupled to an energy dispersive spectrometer to determine surface morphology, topography, composition and coating thickness. Corrosion properties were tested in dilute Harrison’s solution (3.5 g/L (NH4)2SO4 and 0.5 g/L NaCl) using electrochemical impedance spectroscopy. The copolymerization of MMA and MAPTMS over 4 h was optimal for obtaining 1.4 µm thick coating with superior barrier protection against corrosion attack (|Z10 mHz| ~ 1 GΩ cm2) during three months of exposure to the corrosive medium.

scholarly journals Nanostructured polyurethane perylene bisimide ester assemblies with tuneable morphology and enhanced stability

2018 ◽  
Vol 5 (3) ◽  
pp. 171686 ◽  
Author(s):  
Xiaoxiao Zhang ◽  
Tingyuan Gong ◽  
Hong Chi ◽  
Tianduo Li
Keyword(s):  
Self Assembly ◽  
Thermo Gravimetric Analysis ◽  
Size Control ◽  
Gel Permeation Chromatography ◽  
Decomposition Temperature ◽  
Inorganic Materials ◽  
Quantum Yields ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Perylene Bisimide

Size control has been successfully achieved in inorganic materials, but it remains a challenge in polymer nanomaterials due to their polydispersity. Here, we report a facile approach to tailor the diameters of polyurethane (PU) nanoparticles (490 nm, 820 nm and 2.1 µm) via perylene bisimide (PBI) assisted self-assembly. The formed morphologies such as spindle, spherical and core–shell structures depend on the ratio of PBI and polymer concentrations. It is shown that the formation of PU nanoparticles is directed by π–π stacking of PBI and the morphology transition is not only affected by the amount of PBI incorporated, but also influenced by solvent, which controls the initial evaporation balance. Furthermore, the prepared PUs exhibit retained optical stability and enhanced thermal stability. The PUs, designed to have conjugated PBI segments in backbones, were synthesized via ring-opening and condensation reactions. Compared with the neat PU, gel permeation chromatography shows narrower molecular weight distribution. Fluorescence spectra and ultraviolet–visible spectra indicate retained maximum emission wavelength of PBI at 574 nm and 5.2% quantum yields. Thermo-gravimetric analysis and differential scanning calorimetry reveal 79°C higher decomposition temperature and 22°C higher glass transition temperature. This study provides a new way to fabricate well-defined nanostructures of functionalized PUs.

scholarly journals In vitro Complexation of Olmesartan Medoxomil with Dapagliflozin, Vildagliptin and Metformin

2019 ◽  
Vol 18 (2) ◽  
pp. 271-280 ◽  
Author(s):  
Fahima Aktar ◽  
Md Zakir Sultan ◽  
Mohammad A Rashid
Keyword(s):  
Drug Interactions ◽  
Thermo Gravimetric Analysis ◽  
Olmesartan Medoxomil ◽  
Therapeutic Agents ◽  
Gravimetric Analysis ◽  
Thermochemical Properties ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Ft Ir

Drug-drug interactions have been a serious concern for pharmacokinetics, pharmacodynamics and pharmacological profiles of therapeutic agents. The aim of this study was to carry out interactions of olmesartan medoxomil with dapagliflozin, vildagliptin and metformin, which were confirmed by TLC, HPLC and FT-IR. The newly formed complexes showed characteristic thermochemical properties in differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). In TLC, three spots from the three complexes were found to be different from their precursor drugs. In HPLC chromatograms, the Rt (retention time) of the pure olmesartan medoxomil, dapagliflozin, vildagliptin and metformin were found to be different from their respective complexes. The FT-IR spectra obtained for drug-drug interactions were seen to demonstrate new pattern of peaks compared to pure drugs. The DSC and TGA thermograms of olmesartan medoxomil, dapagliflozin, vildagliptin and metformin were also found to be different from their complexes. All these variations from parent compounds indicated the formation of new complexes. Dhaka Univ. J. Pharm. Sci. 18(2): 271-180, 2019 (December)

Electrosynthesis of a Duplex Coating Consisting of a Cerium-Based Layer and a Polypyrrole Film for the Corrosion Protection of AISI 304 Stainless Steel

2021 ◽  
Vol 8 ◽  
pp. 1-11
Author(s):  
A.P. Loperena ◽  
I.L. Lehr ◽  
S.B. Saidman
Keyword(s):  
Stainless Steel ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
304 Stainless Steel ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Protection Efficiency ◽  
Duplex Coating ◽  
Polypyrrole Film

Duplex coating consisting of an inner cerium-based layer and polypyrrole (PPy) film topcoat was electrodeposited onto AISI 304 stainless steel. The cerium-based coating was electrodeposited in solutions containing cerium nitrate at 50 ºC. The polymeric outer layer was electropolymerized in the presence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT). The electrosynthesis was done under potentiostat conditions. The coatings were characterized by scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDX). The morphology of the double-layered cerium polypyrrole film shows a granular structure with the presence of agglomerates of small grains. The anticorrosive performance of the coatings was evaluated in sodium chloride solution by linear polarization, open circuit measurements, and electrochemical impedance spectroscopy (EIS). Single films, cerium layer and PPy coating, and the duplex film all reduce the corrosion rate of AISI 304 stainless steel in NaCl solution. The duplex coating presents an improved corrosion resistance concerning the single films. The combination of the characteristics of the single layers is responsible for the superior corrosion protection efficiency of the double-layered cerium polypyrrole coating.

scholarly journals Blended Coatings from Polyaniline (PANI) and Chemically Doped Sodium Docecyl Benzene Sulphonate (SDBS)/SiO2 Nanocomposites: Influence on Corrosion Protection of Mild Steel

2021 ◽  
Author(s):  
N.Dhana Raj ◽  
Smita Mohanty ◽  
Sanjay Nayak (Self-nomination)
Keyword(s):  
Contact Angle ◽  
Mild Steel ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
In Situ Polymerization ◽  
Thermo Gravimetric Analysis ◽  
Coated Sample ◽  
Nanocomposite Coatings ◽  
Gravimetric Analysis ◽  
Water Contact

Abstract In this work, investigation on corrosion protection performance of chemically synthesized polyaniline (PANI) / SiO2nanocomposite coatings has been carried out on Mild Steel (MS). Sodium docecyl benzene sulphonate (SDBS) doped conducting PANI / SiO2at different ratios was synthesized by employing in -situ polymerization technique. The developed coatings were characterized using Fourier transform infrared spectroscopy (FTIR), Thermo gravimetric analysis (TGA), Transmission electron microscopy (TEM), Contact angle, Atomic force microscopy (AFM) and corrosion analysis. The FTIR analysis indicates the strong interaction between PANI and SiO2 nanoparticles. The contact angle study reveals the hydophillicity character of the nanocomposite coatings with a water contact angle of 74.9°. Corrosion resistanceof uncoated mild steel and the coated sample in 3.5 % NaCl aqueous solution has been evaluated using weight loss methods. Additionally the Electrochemical Impedance Spectroscopy (EIS) studies have been also conducted to evaluate the coorision protection characteristics of the coatings. PANI containing SiO2 (PSC III) coating showed excellent resistance after immersion in 3.5 % NaCl solution for 1 month time period.

Self-Assembly of Methacrylic Nanostructured Copolymers Containing Polyhedral Oligomeric Silsesquioxanes

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
D. Molina ◽  
M. Levi ◽  
S. Turri ◽  
M. Penso
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Butyl Methacrylate ◽  
Random Copolymers ◽  
Gravimetric Analysis ◽  
X Rays ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Scanning Calorimetry ◽  
Free Radical Copolymerization ◽  
Hybrid Copolymer

AbstractTwo hybrid copolymer series obtained by free-radical copolymerization of methacrylcyclohexyl Polyhedral oligomeric silsesquioxane (POSS) with butyl methacrylate or 2-ethylhexylmethacrylate were characterized by 1H-NMR spectroscopy, gel permeation chromatography (GPC), X-rays Diffraction (XRD), differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Reactivity ratios were calculated by low yield composition data suggesting the formation of random copolymers with low probability of poly-POSS sequences. XRD studies showed the crystallization behaviour of the inorganic phase independently on the POSS content; however sample processing by solvent casting effectively hindered the copolymer self-assembling ability. DSC suggests the formation of polyphasic structures with Tg increasing with POSS content, and with endothermal peaks occurring at higher temperature. Finally TGA shows an improved thermal stability of hybrid copolymers with char yield correlated to the level of inorganic phase.

scholarly journals Influence of different functionalization methods of multi-walled carbon nanotubes on the properties of poly(L-lactide) based nanocomposites

2019 ◽  
Vol 73 (3) ◽  
pp. 183-196 ◽  
Author(s):  
Nevena Vukic ◽  
Ivan Ristic ◽  
Milena Marinovic-Cincovic ◽  
Radmila Radicevic ◽  
Branka Pilic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes ◽  
Functionalized Mwcnts

This paper presents influence of the type of carbon nanotube functionalization on properties of poly(L-lactide) (PLLA) based nanocomposite materials. For this purpose surface modifications of multi-walled carbon nanotubes (MWCNTs) were performed by chemical and irradiation techniques, while thermo gravimetric analysis, UV-Visible and Fourier-transform infrared (FT-IR) spectroscopies confirmed successful covalent functionalization. Series of PLLA bionanocom-posites with different contents of functionalized MWCNTs (0.7; 1.6; 2.1 wt%), were synthesized via ring-opening solution polymerisation of L-lactide. FT-IR analysis confirmed that grafting of L-lactide, under controlled condition, is possible to perform starting from the surface of functionalized MWCNTs. From differential scanning calorimetry results it was concluded that even low contents of chemically and irradiation functionalized MWCNTs had a significant effect on thermal properties of the prepared nanocomposites, raising the values of melting and glass transition temperatures. Thermogravimetric analysis (TGA) has shown that the degradation onset temperature for composites with chemically functionalized MWCNTs, was much higher than that for the neat poly(L-lactide) sample and composites with irradiation functionalized MWCNTs. Morphology studies by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that poly(L-lactide) covered surfaces and separated functionalized MWCNTs. Good dispersion of carbon nanotubes in polymer matrix enabled conductivity of synthesized materials, as determined by conductivity tests.

scholarly journals Oxidation Behavior of an Austenitic Steel (Fe, Cr and Ni), the 310 H, in a Deaerated Supercritical Water Static System

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 571
Author(s):  
Aurelia Elena Tudose ◽  
Ioana Demetrescu ◽  
Florentina Golgovici ◽  
Manuela Fulger
Keyword(s):  
Stainless Steel ◽  
Supercritical Water ◽  
Nuclear Reactor ◽  
Electrochemical Impedance ◽  
Electrochemical Methods ◽  
Metallographic Analysis ◽  
Gravimetric Analysis ◽  
Static System ◽  
Eis Measurements ◽  
Supercritical Temperature

The aim of this work was to study the corrosion behavior of a Fe-Cr-Ni alloy (310 H stainless steel) in water at a supercritical temperature of 550 °C and a pressure of 250 atm for up to 2160 h. At supercritical temperature, water is a highly aggressive environment, and the corrosion of structural materials used in a supercritical water-cooled nuclear reactor (SCWR) is a critical problem. Selecting proper candidate materials is one key issue for the development of SCWRs. After exposure to deaerated supercritical water, the oxides formed on the 310 H SS surface were characterized using a gravimetric analysis, a metallographic analysis, and electrochemical methods. Gravimetric analysis showed that, due to oxidation, all the tested samples gained weight, and oxidation of 310H stainless steel at 550 °C follows parabolic rate, indicating that it is driven by a diffusion process. The data obtained by microscopic metallography concord with those obtained by gravimetric analysis and show that the oxides layer has a growing tendency in time. At the same time, the results obtained by electrochemical impedance spectroscopy (EIS) measurements indicate the best corrosion resistance of Cr, and (Fe, Mn) Cr2O4 oxides developed on the samples surface after 2160 h of oxidation. Based on the results obtained, a strong correlation between gravimetric analysis, metallographic analysis, and electrochemical methods was found.

Performance of coatings containing treated silica fume in the corrosion protection of reinforced concrete

2018 ◽  
Vol 47 (4) ◽  
pp. 350-359 ◽  
Author(s):  
Nivin M. Ahmed ◽  
Mostafa G. Mohamed ◽  
Reham H. Tammam ◽  
Mohamed R. Mabrouk
Keyword(s):  
Reinforced Concrete ◽  
Silica Fume ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Dual Function ◽  
Core Shell ◽  
Protection Efficiency ◽  
Content Type ◽  
Anticorrosive Pigments

Purpose This study aims to apply novel anticorrosive pigments containing silica fume-phosphates (Si-Ph), which were prepared using core-shell technique by covering 80-90 per cent silica fume (core) with 10-20 per cent phosphates (shell) previously, to play dual functions simultaneously as anticorrosive pigments in coating formulations and as an anticorrosive admixture in concrete even if it is not present in the concrete itself. Two comparisons were held out to show the results of coatings on rebars containing core-shell pigments in concrete, and concrete admixtured with silica fume can perform a dual function as anticorrosive pigment and concrete admixture. The evaluation of corrosion protection efficiency of coatings containing core-shell pigments and those containing phosphates was performed. Design/methodology/approach Simple chemical techniques were used to prepare core-shell pigments, and their characterization was carried out in a previous work. These pigments were incorporated in solvent-based paint formulations based on epoxy resin. Different electrochemical techniques such as open-circuit potential and electrochemical impedance spectroscopy were used to evaluate the anticorrosive efficiency of the new pigments. Findings The electrochemical measurements showed that concrete containing coated rebars with core-shell pigments exhibited almost similar results to that of concrete admixtured with silica fume. Also, the anticorrosive performance of coatings containing Si-Ph pigments offered protection efficiency almost similar to that of phosphates, proving that these new pigments can perform both roles as anticorrosive pigment and concrete admixture. Originality/value Although the new Si-Ph pigments contain more than 80 per cent waste material, its performance can be compared to original phosphate pigments in the reinforced concrete.

scholarly journals Biocomposites of Bio-Polyethylene Reinforced with a Hydrothermal-Alkaline Sugarcane Bagasse Pulp and Coupled with a Bio-Based Compatibilizer

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2158
Author(s):  
Nanci Vanesa Ehman ◽  
Diana Ita-Nagy ◽  
Fernando Esteban Felissia ◽  
María Evangelina Vallejos ◽  
Isabel Quispe ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Water Absorption ◽  
Sugarcane Bagasse ◽  
Thermo Gravimetric Analysis ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Cradle To Gate ◽  
Bagasse Pulp

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.

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