scholarly journals Modification of water-suspension epoxy varnish and paint materials by nanostructured magnesium oxide

2020 ◽  
Vol 56 (1) ◽  
pp. 105-113
Author(s):  
V. V. Komar ◽  
T. A. Poсhodina ◽  
N. V. Kulinich ◽  
N. P. Krutko ◽  
L. V. .Ovseenko
Keyword(s):  
Magnesium Oxide ◽  
Protective Coatings ◽  
Curing Temperature ◽  
Aggregative Stability ◽  
Functional Surface ◽  
Properties Of Coatings ◽  
Mechanical Dispersion ◽  
Bead Mill ◽  
Powder Suspension ◽  
Size Of Particles

The process of modifying aqueous powder suspension materials (APS) based on solid epoxy film-forming agents with highly dispersed powders of magnesium oxide was studied: production by ChemPur (n-MgO – primary size of particles is 36 nm), and magnesium oxide synthesized by a template method from the concentrated bischofite solution (MgOlab – primary size of particles is 102.8 nm). It was shown that presence of active functional surface OHgroups in both samples of magnesium oxide leads to the formation of secondary structures: aggregates and agglomerates. The nature of the influence of the size of aggregates of MgO particles and the conditions of dispersion on the properties of protective coatings is established. The nature of the influence of particle size and dispersion conditions on the properties of protective coatings is established. Optimal properties of coatings based on APS, sedimentation and aggregative stability of suspensions are implemented only under the condition of effective mechanical dispersion in a bead mill, when the most intensive destruction of large aggregates of n-MgO up to 50–60 nm occurs. The distribution of nanoparticle agglomerates in APS at the micro level (700–800 nm) using the MgO-lab does not lead to a significant change in the properties of APS and coatings based on them.It is shown that the introduction of n-MgO into APS allows reduces the curing temperature of the coatings from 110 to 90–100 °С. It is caused by the increase in the density of cross-linking of the spatial structure of polymer. The strength of modified coatings upon impact and tension increases by 2 times in comparison with the base composition, which does not contain nanomodifier, during curing of coatings at100 °C. In comparison with the known water-borne epoxy paints and varnishes, APS compositions are one-pack, they are more technological in use, have a long lifetime (up to 12 months in comparison with the viability of known two-pack epoxies, 1-8 hours). Materials can be used in industry for the protection of metal products, both as primers and as independent coatings.

scholarly journals Mechanical Properties of Protective Coatings against Marine Fouling: A Review

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 173
Author(s):  
Alessandro Pistone ◽  
Cristina Scolaro ◽  
Annamaria Visco
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Protective Coatings ◽  
Scale Up ◽  
Product Distribution ◽  
Properties Of Coatings ◽  
Fouling Organism ◽  
Ship Hulls ◽  
Marine Industry ◽  
Application Fields

The accumulation of marine organisms on ship hulls, such as microorganisms, barnacles, and seaweeds, represents a global problem for maritime industries, with both economic and environmental costs. The use of biocide-containing paints poses a serious threat to marine ecosystems, affecting both target and non-target organisms driving science and technology towards non-biocidal solutions based on physico-chemical and materials properties of coatings. The review reports recent development of hydrophobic protective coatings in terms of mechanical properties, correlated with the wet ability features. The attention is focused mainly on coatings based on siloxane and epoxy resin due to the wide application fields of such systems in the marine industry. Polyurethane and other systems have been considered as well. These coatings for anti-fouling applications needs to be both long-term mechanically stable, perfectly adherent with the metallic/composite substrate, and capable to detach/destroy the fouling organism. Prospects should focus on developing even “greener” antifouling coatings solutions. These coatings should also be readily addressable to industrial scale-up for large-scale product distribution, possibly at a reasonable cost.

Simulation of Mechanical Properties of Light-Burned Magnesium Oxide-Containing Concrete for Historical Dam Temperatures

2017 ◽  
Vol 744 ◽  
pp. 45-54
Author(s):  
Yong Min Yang ◽  
Zhao Heng Li ◽  
Tong Sheng Zhang ◽  
Qi Jun Yu
Keyword(s):  
Mechanical Properties ◽  
Body Temperature ◽  
Magnesium Oxide ◽  
Constant Temperature ◽  
Variable Temperature ◽  
Curing Temperature ◽  
Engineering Practice ◽  
Curing Conditions ◽  
Mgo Concrete ◽  
Curing Regime

Previous studies showed that curing regime has a significant influence on mechanical properties of light-burned magnesium oxide (MgO) concrete. However, research has been limited mostly to constant-temperature studies, whereas dams manufactured from concrete exist in variable-temperature environments. In order to achieve material performance parameters that agree more closely with engineering practice, the development of mechanical properties of light-burned MgO concrete curing at constant temperature and simulated dam body temperature was studied. The compressive strength, elastic modulus and ultimate tensile strain of light-burned MgO concrete increased with the increase of curing temperature, MgO content and curing age. These constant-temperature properties were similar to those under simulated dam body temperature curing conditions. A comparison of experimental results of simulated dam body temperature curing and constant temperature curing showed that a thermostatic curing system was suitable for calculating the laws of mechanics development for dam concrete.

scholarly journals Modification of powder epoxy compositions with highly dispersed magnesium oxide

2020 ◽  
Vol 56 (2) ◽  
pp. 220-228
Author(s):  
V. V. Komar ◽  
T. A. Pochodina ◽  
N. V. Kulinich ◽  
N. P. Krut’k ◽  
L. V. Ovseenko
Keyword(s):  
Low Temperature ◽  
Magnesium Oxide ◽  
Functional Properties ◽  
Protective Coatings ◽  
Polymer Network ◽  
Physicomechanical Properties ◽  
Polymerization Process ◽  
Highly Dispersed

The process of forming epoxy powder compositions with the participation of highly dispersed magnesium oxide in the preparation of compositions by extrusion mixing of components in the melt is investigated. It is established that highly dispersed MgO particles participate in the polymerization process and act as additional crosslinking units of defective regions of the polymer network, which improves the functional properties of epoxy powder compositions. Coatings based on modified compositions are characterized by high physicomechanical properties at low temperature curing (130 °С) and can be used to form protective coatings on heat-sensitive products.

Bitumen Modification

2014 ◽  
Vol 880 ◽  
pp. 3-6 ◽  
Author(s):  
Olga I. Slavgorodskaya ◽  
Vladimir G. Bondaletov ◽  
Yulia P. Ustimenko
Keyword(s):  
Process Parameters ◽  
Curing Temperature ◽  
Optimum Process ◽  
Properties Of Coatings ◽  
Bitumen Modification

The possibility of using epoxidized petroleum resins for modification of bitumen was shown. The dependence of the properties of coatings based on polymeric-bitumen compositions of the number of modifiers, hardening agent and the curing temperature was investigated. The optimum process parameters for polymeric-bitumen compositions were identified. The resistance of the coatings to different environments was investigated.

scholarly journals New Technological Concept for Thermal Spray Protective Coatings

2017 ◽  
Vol 62 (3) ◽  
pp. 1499-1504
Author(s):  
B. Szczucka-Lasota ◽  
J. Piwnik
Keyword(s):  
Protective Coating ◽  
Protective Coatings ◽  
High Velocity Oxygen Fuel ◽  
Cooling Process ◽  
Properties Of Coatings ◽  
Jet Cooling ◽  
Structure Of Coatings ◽  
Erosion Properties ◽  
Oxygen Fuel ◽  
Wear Tests

Abstract Thermally spraying with micro-jet cooling is an innovate technology. It is possible to get fine dispersive structure of coatings during the shorter time in comparable to the classical high velocity oxygen fuel process (HVOF). It corresponds with good corrosion-erosion properties of structure. In the paper the parameters of the spraying with micro-jet cooling process are presented. The selected properties of coatings obtained by hybrid method are presented. The results of wear tests for hybrid and HVOF coating are compared. Results of investigation are very optimistic. The presented technology should be adapted to the actual production of protective coating for machines and construction working in wear conditions.

scholarly journals Curing kinetics of alkyd/melamine resin mixtures

2009 ◽  
Vol 63 (6) ◽  
pp. 629-635 ◽  
Author(s):  
Mirjana Jovicic ◽  
Radmila Radicevic
Keyword(s):  
Castor Oil ◽  
Protective Coatings ◽  
Curing Kinetics ◽  
Isoconversional Method ◽  
Curing Temperature ◽  
Melamine Resin ◽  
Alkyd Resins ◽  
Synthetic Resins ◽  
Isothermal Kinetic ◽  
Kinetics Of

Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor oil with melamine resin, has been studied by DSC method with programmed heating and in isothermal mode. The results determined from dynamic DSC curves were mathematically transformed using the Ozawa isoconversional method for obtaining the isothermal data. These results, degree of curing versus time, are in good agreement with those determined by the isothermal DSC experiments. By applying the Ozawa method it is possible to calculate the isothermal kinetic parameters for the alkyd/melamine resin mixtures curing using only calorimetric data obtained by dynamic DSC runs. Depending on the alkyd resin type and ratio in mixtures the values of activation energies of curing process of resin mixtures are from 51.3 to 114 kJ mol-1. The rate constant of curing increases with increasing the content of melamine resin in the mixture and with curing temperature. The reaction order varies from 1.12 to 1.37 for alkyd based on dehydrated castor oil/melamine resin mixtures and from 1.74 to 2.03 for mixtures with alkyd based on castor oil. Based on the results obtained, we propose that dehydrated castor oil alkyd/melamine resin mixtures can be used in practice (curing temperatures from 120 to 160?C).

Spraying Coatings by Supersonic Metallization

2000 ◽  
Author(s):  
I. Karp ◽  
A. Rudoy
Keyword(s):  
High Speed ◽  
Protective Coatings ◽  
Combustion Products ◽  
Arc Spraying ◽  
Supersonic Stream ◽  
Properties Of Coatings ◽  
Equipment Complex ◽  
Motor Component ◽  
Specialized Equipment ◽  
Hydrocarbon Gas

Abstract A technology and a specialized equipment complex based on supersonic arc spraying gun, where a supersonic stream of combustion products of hydrocarbon-gas (HC-gas) with air is used as an atomizing gas, have been developed. Durable and safe work of coated parts functioning under conditions of intensive loading is determined (except general requirement to coatings: wear resistance, hardness) to a large extent by the fatigue strength, porosity and stability of the properties of coatings. New possibilities for satisfying all the requirement to coatings on parts type are opened up by a high speed spraying of wire. This is provided at the expanse of raising the kinetic energy of particles under spray, increase of their concentration in metal stream, lowering of the spread of parameters in the vicinity of a substrate. This, in its turn, determines the increase of adhesive and cohesive strength of coating, the decrease of oxidation, the improvement of stability and reproducibility of its properties. The results of the investigations of the influence of the variable parameters of the process on the listed above properties of coatings are presented. This technology and equipment complex is appreciated for repair of wearied motor component and deposition of corrosion protective coatings.

scholarly journals STRUCTURE AND PROPERTIES OF COATINGS BASED ON FeCrAl AND Cr18Ni10T

2020 ◽  
pp. 125-131
Author(s):  
V.А. Belous ◽  
М.A. Bortnitskaya ◽  
R.L. Vasilenko ◽  
V.N. Voyevodin ◽  
І.О. Klimenko ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Protective Coatings ◽  
Vacuum Arc ◽  
Properties Of Coatings ◽  
Corrosion Properties ◽  
Composition Optimization ◽  
Vacuum Arc Deposition ◽  
Mechanical And Corrosion Properties ◽  
Reaction Atmosphere ◽  
Mechanical Properties And Corrosion

The process of vacuum-arc deposition of protective coatings from multicomponent FeCrAl cathodes and 18Cr10NiT stainless steel onto fragments of Zr1Nb alloy claddings has been developed. The influence of the reaction atmosphere (vacuum, nitrogen, oxygen) during the deposition of coatings on their structure, mechanical and corrosion properties is investigated. Coatings deposited in vacuum from the Cr18Ni10T cathode have the best set of mechanical properties and corrosion resistance; whereas coatings based on FeCrAl require composition optimization. It has been established that coatings deposited from FeCrAl and stainless steel cathodes with a thickness of 20 μm significantly increase oxidation resistance and prevent the destruction of fuel cladding under exposure to air at 1150 °C for 1 h.

scholarly journals The Influence of Organically Modified Derivatives of Silica on the Structure and the Wetting Angle Values of Silica Coatings

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1058
Author(s):  
Anna Adamczyk
Keyword(s):  
Porous Materials ◽  
Protective Coatings ◽  
Deposition Process ◽  
Dip Coating ◽  
Wetting Angle ◽  
Properties Of Coatings ◽  
Metallic Substrates ◽  
Silica Coatings ◽  
Silica Precursor ◽  
Silica Sols

The surrounding environment often acts in a destructive way on materials we apply in our everyday life. The best way to protect them against such activity is to cover the basic materials with coatings possessing different properties, tailored to their applications. Anticorrosive layers are one of the biggest groups of such protective coatings, especially those containing silica or its derivatives. Depending on a type of silica precursor and a method of deposition, one can obtain coatings of different structures and properties. In this work, three different silica precursors were applied: TEOS (tetraethylorthosilane), DDS (dimethyldiethoxysilane) and AerosilTM (the powder silica). Sols of different concentrations of the aforementioned precursors as well as commercially available preparations (Sarsil H1 4/2 and SILOXAN W290) were applied for thin films deposition by a dip coating or an infiltration method. The substrates could be divided in two groups: metallic (steel and titanium or titanium alloys) and porous (represented by old brick, sandstone and limestone). Following the deposition process, the layers on metallic substrates were additionally annealed at 500 °C to improve their adhesion and mechanical properties, while those on porous materials were dried in air. All prepared coatings were primarily studied by FTIR spectroscopy and X-ray diffraction. The morphology of their surfaces was imaged by SEM and AFM microscopies, which also allowed determination of the roughness of obtained materials. The measurements of wetting angle values enabled to find the relationship between the surface topography, the type of silica precursor and the hydrophobic/hydrophilic properties of the samples. The results confirmed the hydrophobic properties of coatings obtained by the infiltration technique on the porous materials and the high hydrophilicity of the annealed thin film deposited on the metallic substrates.

Sign in / Sign up

Export Citation Format

Share Document