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Abstract

The main objective of this paper is to investigate the coexistence of polymers and nanoparticles, demonstrating improved mechanical and corrosion resistance characteristics when applied to mild steel surfaces. For this investigation, various polymer-based hybrid nanocomposite combinations were considered. Combinations of nanomaterials, such as multiwalled carbon nanotubes (MWCNTS), zinc oxide (ZnO), cerium oxide (CeO₂), silicon oxide (SiO₂), and graphene oxide nanoparticles (GO), as well as polymers including polyester, phenolic, epoxy, and polyurethane were employed. Mild steel samples covered with hybrid nano composites underwent 3.5% NaCl immersion and standard Salt Spray (Fog) test method ASTM B117:2016 to evaluate their corrosion resistant qualities. Tensile strength test (A370:2017) and hardness test [IS 101(Part-5, Sec.2):1988] were performed and determined the mechanical properties. An ideal proportion of polymer and nanoparticles combination that results in both enhanced mechanical and corrosion resistance characteristics was determined in this study. From the obtained results, epoxy resin has been exhibited a 97% corrosion resistance, with a 10% increase in tensile strength around 700 mg of surface hardness. The MSPS3 recorded with the highest of all the combination values of 89% corrosion resistance, 400 mg of surface scratch hardness and 25% increased tensile strength. In case of MZPU2, 80% corrosion resistance, 25% increased tensile strength with 600 mg of surface hardness. Whereas MGPH1 shown 69% anticorrosion, 600 mg of scratch hardness and 27% rise in tensile strength. With these outputs, this research can be applied to various materials for different engineering applications.

Keywords

multi-walled carbon nano tubes zinc oxide nano particles cerium oxide nano particles silicon oxide nano particles and graphene oxide nano particles polyurethane epoxy phenolic polyester coating anticorrosion mechanical properties

Introduction

Corrosion is the process by which the external environment causes a chemical reaction on a metal surface, reducing the metal’s strength. When ferrous material comes into contact with chemicals and atmospheric moisture, an electrochemical reaction known as corrosion naturally occurs. Corrosion has a negative impact on the structure and is a major risk to building engineering. Steel structures corrode and crumble as a result. Numerous oil pipelines sustain damage, which might result in chemical plant leaks, etc. The cost of maintaining a structure increases due to corrosion. Corrosion causes a reduction in shear capacity, ductility, and structural strength.¹

Adhering to corrosion resistance techniques is essential to preventing corrosion in the buildings. The finest quality features are possessed by multi-walled carbon nanotubes (MWCNT), which find extensive commercial uses. When included into a composite construction, MWCNT functions well as an electrical conductor. With a length to diameter ratio of 100:1, it has a high aspect ratio.² Its tensile straightness is outstanding. Nonetheless, thermoset or thermoplastic materials can boost strength. MWCNTs as materials for woven or non-woven fabrics or as resin implants When bucky paper is submerged in thermoset resins, it significantly improves the quality and hardness of composite structures, such as golf club shafts and structural laminates used in aerospace applications.^3,4

The silica-based organic and inorganic material has numerous benefits, including outstanding strength, superior barrier performance, and ease of processing. Catalysts, optical devices, protective coatings, and composites are its principal applications. Nanotechnology The chemical compound silicon oxide (SiO₂), often known as silica, is an oxide of silicon. Silica is what sand is thought to be. Another name for silicon oxide nanoparticles is silica nano-silica. The primary use of silica nanoparticles is as an addition in rubber and polymers. They serve as reinforcing fillers in composite construction materials. By incorporating SiO₂ nanoparticles into the resin composition, diapering the material can enhance its performance. The materials' improved surface finishing qualities, strength, elongation, anti-aging, and water resistance are all examples of the improvement.⁵ Epoxy resin (E) substance is distinguished by its strong electrical characteristics and resistance to chemicals. It is quite strong and absorbs little moisture. Two significant categories of epoxy resins are non-glycidyl and glycocidyl epoxy. Epoxy is exceptionally strong mechanically. In comparison, it is less expensive. Epoxy resin is incredibly resistant to chemicals. It also has thermal resistance. It is the perfect chemical for usage in electronics, electrical systems, and other industrial settings. Epoxy resins have minimal curing contraction and exceptional mechanical strength. The most widely used nanofillers include carbon nanotubes, montmorillonites, fullerenes, and nano silica.⁶

Utilizing acetonitrile at 70°C, a straightforward and efficient green in situ solvothermal reduction technique of multi-layered graphene oxide (MLGO) was created to create a hydrophobic and corrosion-resistant epoxy coating on carbon steel. FT-IR, TGA, Raman spectroscopy, and mapping EDX research demonstrated that acetonitrile was a successful solvothermal reducer of MLGO. In comparison to MLGO/epoxy, the long-term salt spray and EIS analysis demonstrated that reduced multi-layered graphene oxide (RMLGO)/epoxy nano-coating provided better corrosion protection. The hydrophobic property of the RMLGO/epoxy coating was confirmed by the water contact angle tests, which yielded results of 66.66°, 72.18°, and 91.66° for the pure epoxy, MLGO/epoxy, and RMLGO/epoxy coatings, respectively. Additionally, TEM pictures demonstrated that the RMLGO generated by in situ solvothermal reduction had a higher grade of dispersion than that of ex-situ solvothermal reduction

Mild steel is essential to a civil engineering structure’s longevity, while carbon steels' performance is typically compromised by surface characteristics including surface roughness and surface energy from corrosion.^1,7 Because of the decline in shear capacity, ductility, bond strength, and structural strength, it is seriously affecting the building industry.^8,9 There have been numerous attempts to improve the tensile strength and prevent corrosion of mild steel by surface coating techniques such as inorganic coatings, paints, resins, alloying additives, and many more. Numerous resin kinds have been independently investigated in the literature and have been shown to be highly successful in preventing the corrosion of civil structures. Numerous investigators have assessed the anticorrosion capabilities of diverse resin coating varieties on mild steel surfaces. When applied to galvanized steel, epoxy-silane hybrid coatings with coating ratios ranging from one to three wt percent have been shown to increase the surface’s adhesion and corrosion behavior. However, when applied up to 5 weight percent, the surface’s corrosion and adhesion performance was reduced.^10,11 The results of the scanning Kelvin probe (SKP) demonstrate that cathodic delamination of polyurethane/multiwalled carbon nanotube composite coatings up to 0.5 wt percent on steel substrate has improved the corrosion protection performance in the NaCl solution.

Potentiodynamic polarization tests and EIS corrosion-performance evaluation studies in a 3.5 wt% NaCl solution have demonstrated that the MWCNT in polypyrrole (PPY) coating has significantly decreased the corrosion rate.¹² It’s interesting to note that the PPY/MWCNT-COO-functionalized nanocomposite offered a covering with greater corrosion resistance than PPY/MWCNT by itself. When mild steel was coated with 0.75 wt percent MWCNT/epoxy nanocomposite, the corrosion rate dropped to 2.5 × 103 MPY and the protection effectiveness reached 99.99%.¹³ Based on electrochemical experiments, it was discovered that the hybrid coating in a 0.75% saline solution greatly increased the corrosion resistance of carbon steel.^14,15 A different experimental investigation found that the ideal graphene oxide (GO) content for creating GO-epoxy nanocomposites with the best corrosion resistance was around 0.1 wt percent.¹⁶ It was discovered that MWCNTs were evenly distributed throughout the PU matrix at a weight percentage of 4 to 6 wt%, and that no aggregation or precipitation phenomena occurred during the quick spraying procedure.¹⁷ Ramezanzadeh et al.¹⁸ demonstrated that adding 0.1 wt percent GO and PI-GO nanosheets to the polyurethane resin improved its ability to resist corrosion. Studies on specific resin coatings for mild steel surfaces have focused on improving the materials’ mechanical, physical, thermal, water, and antibacterial properties. Still, relatively little study has been done to determine which resin will yield the highest mechanical and anticorrosion qualities when applied to mild steel surfaces. Therefore, the goal of this study is to identify the best resin for a mild steel substrate that would have improved mechanical qualities and anticorrosion. The appropriate accelerator, hardener, and thinners were used to produce the resins (phenolic, epoxy, polyester, and polyurethane). On the mild steel surface that was created, the prepared resins were applied as coatings. In addition, an immersion and salt spray test were used to analyze the corrosion on the surface. Furthermore, tests for scratch hardness and tensile strength were conducted to assess the mechanical characteristics of the mild steel surface. The epoxy’s morphological properties and level of anticorrosion performance,^6,10,14,19 polyurethane,^{12,18,20–25} phenolic ,^20,26,27 and polyester resins^28,29 as mild steel surface coatings were contrasted and talked about.

Materials and experimental methodology

Materials required are multi-walled carbon nanotube’s (MWCNT’s), Zinc Oxide Nano particles (ZO), Silicon Oxide Nano Particles (SiO), Zinc Oxide Nano Particles (ZO), Cerium Oxide (CeO₂) Nanoparticles and Graphene Oxide (GO) Nanoparticles. Resins like Epoxy, Polyurethane, Polyester, and Phenolic. Mild steel, chemicals like Thinner (Thinner-643), Ethanol, Deionized water, Acetone, and Isopropyle alcohol etc.

Nano materials and their details

Multi-walled carbon nanotube’s (MWCNT’s)were prepared by CVD method. The details of Zinc Oxide (ZO), Silicon Oxide (SiO₂), Cerium Oxide (CeO₂) and Graphene Oxide (GO) Nanoparticlesare mentioned below in Table 1.

Table 1.

Technical specification of nanomaterials.

Nano material	Specifications	Value
Multi-walled carbon nanotube’s (MWCNT’s)	Tensile strength	30∼180 GPa (100 times of metal)
	Thermal conductivity	6,000 W/mk (2 times of that of diamond)
	Electric conductivity	6,000S/cm (1000 times of that of copper wire)
	Modulus	1∼2 TPa (7times of that of metal)
	Diameter	10∼15 nm
	Length	2-10 microns
	Purity	>99 %
	Ash content	<0.01 %
	Fe	<4000 mg/kg
	Al	<3500 mg/kg
	Mo	<800 mg/kg
	Specific surface area	250 ∼ 270 m²/g
	Bulk density	0.06 ∼ 0.09 g/cm³
	Physical form	Fluffy, very light powder
	Colour	Black
	Chemical formula	C
Silicon oxide (SiO)	Purity	99.5%
	Average particle size	30–50 nm
	Specific surface area	200–250 m²/g
	Atomic weight	231.533 g/mol
	Bulk density	0.10 g/cm³
	True density	2.5 g/cm³
	Morphology	Porous
	Molar Mass	60.08 g/mol
	Melting point	1600°C
	SiO₂	99.5%
	Al, fe, mg, and Ca	0.02%, 0.05%, 0.1% and 0.08%
Zinc oxide (ZO)	Purity	99.90%
	Average particle size	30–50 nm
	Specific surface area	20–60 m²/g
	Molecular weight	81.408 g/mol
	Bulk density	0.28–0.48 g/cm³
	True density	6 g/cm³
	Morphology	Spherical
	Molecular formula	ZnO
	Physical form	Powder
	Color	Milky white
	ZnO	>99.9%
	Pb, si, Mn, and Cu	<0.01%, <0.02%, <0.02%, and <0.01%
Cerium oxide (CeO₂)	Purity	99.90%
	Average particle size	20–30 nm
	Specific surface area	40–50 m²/g
	Molecular weight	172.1148 g/mol
	Bulk density	1.3 g/cm³
	True density	6.5 g/cm³
	Morphology	Spherical
	Molecular formula	CeO₂
	Physical form	Powder
	Color	Light yellow
	CeO₂	≥99.9%
	SiO_2, TiO₂, MgO, and Al₂O₃	≤0.05, ≤0.06, ≤0.06 and ≤0.05
Graphene oxide (GO)	Concentration	1 mg/mL
	Purity	>95%
	Molecular formula	C
	Molecular weight	12.01 g/mol
	Color	Brown/black
	Appearance	Liquid
	Density	∼2.1 g/cm³at 20°C
	Solvent	Water, ethanol
	pH	2.2-2.5
	Carbon	79%
	Oxygen	20%

Resins selected for fabrication

Two components make up Epoxy Resin (FINECOAT-EP 200A), which is treated with Polyamide Hardener (Fine Coat EP 200/B). At room temperature, or more than 10°C, it cures. An impregnating varnish based on alkyd, phenolic resins, additional reactants, and additives is called INSUFINE®-VI 610. It was impregnated by brush, dip, or spray and complies with IS: 10026-1999 criteria in general. The two-component polyurethane composition FINECOAT-PU500 polyurethane resin is based on acrylic polyol and isocyanate. With the aid of accelerator-1100 and catalyst-1100, the medium viscosity modified ISO polyester resin FINESTER-1100 is cured. Room temperature is used for the curing process (25–40°C). The viscosity range of polyester resin is 300–500 mPa.s@30°;C, its specific gravity is 1.10–1.12, and its acid value is 10–20 mg of KOH/g. Details are provided for Epoxy resin, Polyurethane resin, Polyester resin, and Phenolic resin. Table.2.

Table 2.

Technical specifications of resin.

Resin Specifications
Epoxy	Polyurethane	Polyester	Phenolic
Color: clear. Can be dyed as per the requirement	Color: colorless (PU500/A, PU500/B)	Viscosity range, mPa.s. @30°C: 300 – 500	Color: yellow
Finish: Glossy	Finish: Glossy	Acid value, mg of KOH/g:10-20	Viscosity @25°C (B4 flow cup): 30 - 40 s
Mixing ratio base: hardener = 2:1 (by volume)	Mixing ratio (PU500 A:PU500 B) 1: 1 (by weight)	Color, gardener:< 1	Finish: glossy
Pot life14-16 hours @30°C	Viscosity at 25°C: 15 ± 5 mPa.s	Specific gravity:1.10 – 1.12	Bond strength, at 30°C:25
Theoretical covering capacity: 12 sqm/lit @25 microns dft	Solid content: 60 ± 2%	Volatile content, (max.):40	Volume resistivity at 30°C:1 - 1.5 × 10¹⁶ cm after immersion
Application method: air-assisted/airless spray/brush	Application method: brush/spray	-	-
-	Continuousoperatingtemperature: 155°C	-	-

Experimental procedure

Field emission scanning electron microscopy studies

To investigate, using a field emission scanning electron microscopy (FESEM), the corrosion surface morphology of mild steel covered with MWCNTs, silicon oxide nanoparticles, and epoxy resin in various combinations. To prevent any charging, the corroded surface has been examined using a gold coating, and pictures have subsequently been taken at various magnifications. FESEM was used to operate at a 20 kV accelerating voltage on the corroded surface.

Corrosion analysis

Immersion test

By immersing samples coated in mild steel, the hybrid nanocomposite’s corrosion resistance characteristics were examined. The samples were submerged in 3.5% NaCl-containing distilled water for 336 h, and the weighing method was used to calculate the corrosion rate. To calculate the corrosion rate, the weight of the specimen sample coated with resins was measured both before and after it was submerged in the aforementioned solution.

Salt spray test

The hybrid nanocomposite-coated mild steel’s resistance to corrosion is further assessed using the conventional Salt Spray (Fog) test procedure in accordance with ASTM B117:2016 standard. For the duration of the test, mild steel specimens coated with resins were maintained at a constant temperature and subjected to a fine spray of a 5% salt solution. After the prescribed amount of time, the specimens were rinsed in water and allowed to dry. The percentage of red rust indicates how much the test items have corroded.

Mechanical properties

Tensile strength test

Tensile testing on a universal testing machine (A370:2017) set up in accordance with ASTM standard was used to examine the impact of MWCNT’s hybrid nanocomposite coating on the surface of mild steel. The yield load, ultimate tensile strength, yield stress, and ultimate load were ascertained.

Scratch hardness test

A flat, simple mild steel sample of 120 mm in length, 60 mm in width, and 6 mm in thickness was subjected to a scratch hardness test. The method used for measuring scratch hardness was IS 101 (Part-5, Sec.2):1988. The hardness of the hybrid nano coating was found to be the minimal load required to produce failure.

Specimen preparation

The mild steel specimen with a 12 mm diameter bar was cut to a span of 300 mm (Figure 1) for the tensile test, and the flat specimen with dimensions of 125 × 60 × 6 mm (Figure 2) for the scratch hardness test was sandblasted with P80 sanding paper on the surface before being cleaned and oxides were removed with acetone. After that, the specimen was left to dry for over an hour at room temperature before the resin coating was applied. Following coating, the specimens were allowed to dry at ambient temperature for 48 h before spending an hour in an oven set at 1500°C. Using a pneumatic spray cannon, the produced MWCNTs/2nd Nano particle/Resin Nano composites in various ratios were sprayed onto the mild steel surface. Maintaining a distance of around 100-150 mm between the spraying cannon and the specimen allows for a coating thickness of 160-180 μm.

Figure 1.

Tensile and salt spray test specimen.

Figure 2.

Specimen sample after salt spray test.

The preparation of MWCNTs +2^nd nanoparticles composite

Different percentages of MWCNTs (0.25, 0.5%, 0.75%, and 1% by weight of resin) and second nanoparticles (2%, 4%, 6%, and 8% by weight of resin) were mixed to create nano-composite materials. Both of the nanomaterials were ultrasonically sonicated separately for 30 min in chemical media containing 40% weight of resin in order to disperse them, and then they were combined for an additional 30 min of ultrasonography. The ultra-sonication composite was then mixed using a magnetic stirrer for 30 min at 50°C to create a hybrid nanocomposite of MWCNTs and second nanoparticles. The detailed procedure followed for manufacturing of Nano-composites is shown in Figure 3 schematically. The considered hybrid Nano-composite combinations are shown in Table 3.

Figure 3.

An illustration of the mild steel specimen’s coating procedure.

Table 3.

Hybrid nano-composite combinations.

S. No	Sample description (nano materials by weight of 10 g of resin)	Chemical media used (40 % by weight of resin) for sonication	Sample name
1	0.25% MWCNT –2% silica oxide - Polyester (Resin)	Deionized water	MSPS1
	0.5% MWCNT –4% silica oxide - Polyester (Resin)		MSPS2
	0.75% MWCNT –6% silica oxide - Polyester (Resin)		MSPS3
	1% MWCNT –8% silica oxide - Polyester (Resin)		MSPS4
2	0.25% MWCNT - 2% silica oxide - Epoxy (Resin)	Acetone	MSE1
	0.5% MWCNT - 4% silica oxide - Epoxy (Resin)		MSE2
	0.75% MWCNT - silica oxide - Epoxy (Resin)		MSE3
	1% MWCNT - silica oxide - Epoxy (Resin)		MSE4
3	0.25% MWCNT - 2% graphin oxide - Phenolic (Resin)	Isopropyle alcohol	MGPH1
	0.5% MWCNT - 4% graphin oxide - Phenolic (Resin)		MGPH2
	0.75% MWCNT -6% graphin oxide - Phenolic (Resin)		MGPH3
	1% MWCNT - 8% graphin oxide - Phenolic (Resin)		MGPH4
4	0.25% MWCNT -2% zinc oxide -Polyurathene (Resin)	Acetone	MZPU1
	0.5% MWCNT - 4% zinc oxide -Polyurathene (Resin)		MZPU2
	0.75% MWCNT -6% zinc oxide -Polyurathene (Resin)		MZPU3
	1% MWCNT - 8% zinc oxide -Polyurathene (Resin)		MZPU4
5	0.25% MWCNT - 2% silica oxide -Polyurathene (Resin)	Ethanol	MSPU1
	0.5% MWCNT - 4% silica oxide -Polyurathene (Resin)		MSPU2
	0.75% MWCNT -6% silica oxide -Polyurathene (Resin)		MSPU3
	1% MWCNT -8% silica oxide -Polyurathene (Resin)		MSPU4
6	0.25% MWCNT -2% cerium oxide - Epoxy (Resin)	Acetone	MCE1
	0.5% MWCNT -4%cerium oxide - Epoxy (Resin)		MCE2
	0.75% MWCNT - 6% cerium oxide - Epoxy (Resin)		MCE3
	1% MWCNT - 8% cerium oxide - Epoxy (Resin)		MCE4
7	0.25% MWCNT -2% cerium oxide - Phenolic (Resin)	Acetone	MCPH1
	0.5% MWCNT - 4% cerium oxide - Phenolic (Resin)		MCPH2
	0.75% MWCNT -6% cerium oxide - Phenolic (Resin)		MCPH3
	1% MWCNT - 8% cerium oxide - Phenolic (Resin)		MCPH4
8	0.25% MWCNT - 2%graphine oxide - Polyester (Resin)	Acetone	MGPS1
	0.5% MWCNT -4% Graphine oxide - Polyester (Resin)		MGPS2
	0.75% MWCNT - 6% graphine oxide - Polyester (Resin)		MGPS3
	1% MWCNT - 8% graphine oxide - Polyester (Resin)		MGPS4
9	0.25% MWCNT - 2% zinc oxide - Epoxy (Resin)	Ethanol	MZE1
	0.5% MWCNT -4% zinc oxide - Epoxy (Resin)		MZE2
	0.75% MWCNT -6% zinc oxide - Epoxy (Resin)		MZE3
	1% MWCNT - 8% zinc oxide - Epoxy (Resin)		MZE4
10	0.25% MWCNT - 2% zinc oxide - Polyester (Resin)	Acetone	MZPS1
	0.5% MWCNT - 4% zinc oxide - Polyester (Resin)		MZPS2
	0.75% MWCNT -6% zinc oxide - Polyester (Resin)		MZPS3
	1% MWCNT - 8% zinc oxide - Polyester (Resin)		MZPS4
11	Polyurathene (Resin)	Nil	PU
12	Epoxy (Resin)	Nil	E
13	Polyster (Resin)	Nil	PS
14	Phenolic (Resin)	Nil	PH
15	Mild steel	Nil	MS

Preparation of MWCNT’s + 2^nd nanoparticles + resin composites

The nanocomposite is combined with 10 g of resin, agitated for an hour, and allowed to degas in an ultrasonicator for 20 min. After adding the hardener (Finecoat PU 500B) to the MWCNTs/ZnO/PU mixture, the composite and thinner were manually mixed for 5 minutes. The mild steel (12 mm diameter and 300 mm length) was then cleaned and oxides from its surface were removed by sandblasting it with sanding paper P80 and washing it in acetone. On the mild steel surface, the prepared MWCNT/ZnO/PU nanocomposite coating was sprayed using a pneumatic spray cannon. Maintaining a distance of around 100-150 mm between the spraying cannon and the specimen allows for a coating thickness of 160-180 μm. The mild steel specimens were coated, allowed to dry for 48 h at room temperature, and then placed in an oven set at 150°C for an hour.

The prepared nanocomposite is sprayed using a pneumatic gun method on the mild steel surface, and it is then left to dry at room temperature for 24 h. To find the corrosion rate expressed as a percentage of weight loss, the mild steel samples coated with nanocomposite coating were submerged in distilled water containing 3.5% NaCl for 336 h. After that, they were subjected to a salt spray at 34.8 to 35.1°C, 5% NaCl, salt type AR grade, for 24 h. The AGIS 250 kN fully computerized servo hydraulic universal testing machine was used to perform tensile testing on specimens with the same combinations. For every sample, the toughness property is also computed.

Result and discussion

Corrosion properties of resin coating

Figure 4 displays a plot of the average corrosion resistance qualities for each type of mild steel sample coated with resin that was acquired from an immersion test. In comparison to samples of bare mild steel and hybrid nano coated mild steel, the neat resin coated mild steel samples have demonstrated good results. When compared to the uncoated mild steel surface shown in Table 4, the epoxy resin-coated mild steel sample showed the highest corrosion resistivity at 97%, followed by the polyester resin (85%), polyurethane resin (60%) and phenolic resin (56%) coated samples. Additionally, it is noted that samples coated with epoxy resin have the highest level of corrosion resistance. This is likely due to the chemical structure of the resin, which produces strong chemical resistivity and excellent adhesive qualities in a variety of corrosive environments.

Figure 4.

Anticorrosion protection in percentage.

Table 4.

Corrosion resistance of various Hybrid Nano composite coated mild steel, neat resins coated mild steel and plain mild steel.

S.No	Sample name	% loss of weight due to rust by immersion method (336Hrs)	% loss of weight dueto rust by salt spray (72 Hrs)	Final % loss in weight due to rust (408 Hrs)	% of anticorrosion protection
1	MSPS1	1.05	0	1.05	84.01
	MSPS2	0.96	1.92	2.88	56.16
	MSPS3	0.73	0	0.73	88.88
	MSPS4	0.91	1.92	2.83	56.92
2	MSE1	2.45	3.66	6.11	7.00
	MSE2	2.52	2	4.52	31.20
	MSE3	2.28	1.96	4.2	36.07
	MSE4	2.37	1.92	4.29	34.70
3	MGPH1	2.05	1.92	3.97	39.57
	MGPH2	2.43	0	2.43	63.01
	MGPH3	2.37	0	2.37	63.92
	MGPH4	2.28	1.89	4.17	36.52
4	MZPU1	1.95	1.92	3.87	41.09
	MZPU2	1.32	0	1.32	79.90
	MZPU3	1.53	0	1.53	76.71
	MZPU4	2.05	1.96	4.01	38.96
5	MSPU1	2.41	0	2.41	63.31
	MSPU2	2.45	0	2.45	62.70
	MSPU3	2.24	2	4.24	35.46
	MSPU4	2.79	1.89	4.68	28.76
6	MCE1	0.4	1.89	1.93	70.62
	MCE2	0.55	1.92	2.47	62.40
	MCE3	0.73	0	0.73	88.88
	MCE4	0.53	1.92	2.45	62.70
7	MCPH1	6.75	0	6.42	2.28
	MCPH2	6.5	2.04	6.39	2.73
	MCPH3	8.5	0	6.4	2.58
	MCPH4	7.58	2.08	6.42	2.28
8	MGPS1	6.29	2.04	6.4	2.58
	MGPS2	6.21	0	6.21	5.47
	MGPS3	6.05	0	6.05	7.91
	MGPS4	6.11	0	6.11	7.00
9	MZE1	2.51	1.92	4.43	32.57
	MZE2	3.55	2.19	5.74	12.63
	MZE3	3.3	2.2	5.5	16.28
	MZE4	3.67	4.37	6.04	8.06
10	MZPS1	0.1	0	0.1	98.47
	MZPS2	0.21	0	0.21	96.80
	MZPS3	0.29	0	0.29	95.58
	MZPS4	0.12	0	0.12	98.17
11	PU	0.5	6.06	6.56	0.15
12	E	0.2	2.08	2.28	65.29
13	PS	1.03	4.25	5.28	19.63
14	PH	0.75	4.34	5.09	22.52
15	MS	6.57		6.57

The hybrid Nano-composite mild steel specimens have shown a variety of corrosion resistance. The anticorrosive property of MSPS3 with 89%compared with mild steel sample. The corrosion resistance of MSE3 with is 36%. The oxidation of MGPH1 is 69% increase compared with mild steel sample. The MZPU2 specimen sample shows80% increase match up to mild steel sample. The corrosion resistance of MSPU3 66%rise when mild steel sample is considered. MCE1 specimen sample71% increased anticorrosive property when steel sample was considered. The MCPH2 and MGPS4samples show the least 1%and 7% raise in corrosion resistance with mild steel sample. The anticorrosion property ofMZE1 coated samples shows62% increase among mild steel sample (Table 4). When compared to mild steel samples, the MZPS2 coated samples exhibit a maximum value of around 97% increase in corrosion resistance. Polyester resin FINESTER-1100, which has been adjusted to be a medium viscosity ISO link stronger, has the highest combination of Zinc Oxide Nanoparticles and MWCNTs. This allows the mild steel specimen to stay intact in extremely corrosive and humid environments.

Tensile strength test (A370:2017)

Table 5 lists the mechanical characteristics of nano-composts, when compared to the mild steel surface (456.23 N/mm²), the samples covered with epoxy resin demonstrated the highest ultimate tensile strength of 505.82 N/mm², followed by phenolic resin (491.47 N/mm²), polyurethane resin (485.63 N/mm²), and polyester resin (474.54 N/mm²). When compared to mild steel samples, the epoxy resin-coated samples exhibited a maximum percentage increase in Ultimate Tensile Strength of 9.80%. The superior performance of epoxy resin at elevated temperatures can be attributed to its good physical properties, including toughness, flexibility, and abrasion resistance. In contrast, phenolic resin demonstrated a 7.72% increase, polyurethane a 6.05% increase, and polyester resin the least, showing only a 3.85% increase, when compared to mild steel samples without coating.

Table 5.

Mechanical characteristics of several hybrid nanocomposite mild steels, plain mild steels, and mild steels coated with neat resins.

S.No	Sample name	Yield stress (N/mm²)	Toughness N/mm	UTS (N/mm²)	Elongation%	% Increase in U.T.S
1	MSPS1	348.86	7744.692	494.52	46.25	7.74861765
	MSPS2	312.89	6664.557	466.82	44.38	2.268540337
	MSPS3	458.54	9124.946	605.63	29.57	24.66852699
	MSPS4	339.34	8212.028	500.85	52.61	8.908854947
2	MSE1	352.27	6869.265	508.27	42.39	10.23865268
	MSE2	349.36	7720.856	509.35	47.02	10.42897811
	MSE3	379.32	7207.08	565.75	39.58	19.35837384
	MSE4	362.68	8631.784	513.56	50.64	11.16325259
3	MGPH1	470.10	7991.70	620.74	36.96	26.50223926
	MGPH2	339.83	8325.835	487.44	52.13	6.402839324
	MGPH3	376.66	7796.862	491.25	43.25	7.128753181
	MGPH4	344.00	7602.40	479.29	46.04	4.811283357
4	MZPU1	345.27	6491.076	483.82	40.00	5.702534
	MZPU2	442.73	7836.321	588.02	36.88	22.41250298
	MZPU3	305.41	5894.413	544.06	40.21	16.14344006
	MZPU4	395.76	7559.016	568.76	40.64	19.78514663
5	MSPU1	346.33	8485.085	496.97	53.26	8.197677928
	MSPU2	349.04	7225.128	500.98	44.04	8.932492315
	MSPU3	465.18	9536.19	621.5	44.57	26.59211585
	MSPU4	462.66	8189.082	615.01	37.66	25.81746638
6	MCE1	352.76	9101.208	517.03	56.09	11.75947237
	MCE2	350.77	FALSE	492.68	48.72	7.398311277
	MCE3	370.34	8962.228	495.61	51.49	7.945763806
	MCE4	374.86	9221.556	498.31	52.34	8.444542554
7	MCPH1	341.66	8097.342	504.3	52.67	9.532024589
	MCPH2	339.27	7633.575	495.62	48.91	7.947621161
	MCPH3	346.99	8154.265	514.13	52.22	11.26174314
	MCPH4	435.37	6530.55	580.02	31.25	21.3423675
8	MGPS1	337.57	7460.297	505	48.04	9.657425743
	MGPS2	361.37	9431.757	525.55	58.00	13.18999144
	MGPS3	343.99	8114.7241	503.96	51.28	9.470989761
	MGPS4	368.3	9465.31	533.47	58.41	14.47878981
9	MZE1	406.53	8740.395	585.08	45.74	22.02262938
	MZE2	354.38	7725.484	479.58	45.42	4.868843571
	MZE3	339.55	7610.293	485.21	44.80	5.972671627
	MZE4	359.04	7898.88	491.11	45.83	7.102278512
10	MZPS1	378.09	8329.3227	501.09	47.45	8.952483586
	MZPS2	355.83	8184.09	508.16	50.00	11.38241676
	MZPS3	358.62	8068.95	483.82	46.88	5.702534
	MZPS4	328.36	7519.444	475.09	47.71	3.969774148
11	PU	331.08	5893.224	485.63	37.08	6.053991722
12	E	383.55	7057.32	505.82	38.33	9.803882804
13	PS	356.53	6738.417	474.54	39.38	3.858473469
14	PH	326.93	5394.345	491.47	34.38	7.72417421
15	MS	309.11	6213.111	456.23	41.88	Nil

Plotting the average ultimate tensile strength value over all hybrid Nano coated sample types and resin coated sample types in relation to plain mild steel specimens was done, and the results are displayed in Figures 5–14 through Figure 15. The specimens of mild steel covered with hybrid Nano composite have demonstrated a range of tensile strength. With a 24.66% increase in Ultimate Tensile Strength over the mild steel sample, MSPS3’s tensile strength is 605.63 N/mm². With a 19.35% improvement in Ultimate Tensile Strength over the mild steel sample, the tensile strength of MSE3 is 565.75 N/mm². With a 26.50% improvement in Ultimate Tensile Strength over the mild steel sample, the tensile strength of MGPH1 is 620.74 N/mm². With a 22.41% improvement in Ultimate Tensile Strength above the mild steel sample, the tensile strength of MZPU2 is 588.02 N/mm². With a 26.59% improvement in Ultimate Tensile Strength over the mild steel sample, the tensile strength of MSPU3 is 621.5 N/mm². With an 11.75% improvement in Ultimate Tensile Strength over the mild steel sample, the tensile strength of MCE1 is 517.03 N/mm². With a 7.94% improvement in Ultimate Tensile Strength over the mild steel sample, the tensile strength of MCPH2 is 495.62 N/mm². With a 14.47% improvement in Ultimate Tensile Strength over the mild steel sample, the tensile strength of MGPS4 is 533.47 N/mm². With a 22.02% increase in Ultimate Tensile Strength above the mild steel sample, MZE1’s tensile strength is 585.08 N/mm². With an 11.38% improvement in Ultimate Tensile Strength over the mild steel sample, the tensile strength of MZPS2 is 508.16 N/mm².The mild steel samples coated with MGPH1 and MSPU3 exhibited the highest tensile strength values (about 25% increases) at 620.74 N/mm² and 621.5 N/mm².

Figure 5.

Ultimate load of MSPS.

Figure 6.

Ultimate load of MSE.

Figure 7.

Ultimate load of MGPH.

Figure 8.

Ultimate load of MZPU.

Figure 9.

Ultimate load of MSPU.

Figure 10

. Ultimate load of MCE

Figure 11.

Ultimate load of MCPH.

Figure 12

. Ultimate load of MGPS.

Figure 13.

Ultimate load of MZE.

Figure 14.

Ultimate load of MZPS

Figure 15.

Ultimate load of neat resins.

Toughness test

Figures 16 – 25 show the hardness of mild steel specimens covered with resin and nanocomposites. It is evident that the specimens of mild steel coated with resin and nanocomposites had toughness values that were relatively greater than those of the sample of mild steel without any coating. Out of all the resins, the sample coated with epoxy resin had the greatest toughness index (7057.32 N/mm), followed by the samples coated with phenolic resin (5394.345 N/mm), polyurethane resin (5893.224 N/mm), and polyester resin (6738.417 N/mm). Thanks to the two-component epoxy clear lacquer that was cured with polyamide hardener and had a strong comparative tracking index >500V, the toughness result for the epoxy-coated samples was improved. Furthermore, epoxy resin has physical characteristics that are superior than those of polyester, phenolic, and polyurethane resins.

Figure 16.

Toughness of MSPS samples.

Figure 17.

Toughness of MSE samples.

Figure 18.

Toughness of MGPH samples.

Figure 19.

Toughness of MZPU samples.

Figure 20.

Toughness of MSPU samples.

Figure 21.

Toughness of MCE samples.

Figure 22.

Toughness of MCPH samples.

Figure 23.

Toughness of MGPS samples.

Figure 24.

Toughness of MZE samples

Figure 25.

Toughness of MZPS samples.

The hybrid Nano-composites are processing better toughness index than the neat resins and bare mild steel. The combinationMSPS3 shows the toughness index with 9124.946 N/mm, MSE3 sample toughness index with 7207.08 N/mm, MGPH1 sample toughness index with 7991.70 N/mm, MZPU2coated sample with7836.321 N/mm, MSPU3 coated sample shows the highest toughness index with 9536.19 N/mm, MCE1 coated sample with 9101.208 N/mm, MCPH2 coated sample with 7633.575 N/mm, MGPS4 coated sample with 9465.31 N/mm, MZE1 coated sample with 8740.395 N/mm, andMZPS2 coated sample with 8184.09 N/mm. Amongst all above samples MSPS3, MGPS4 and MZPS2 samples with polyester resin with a medium viscosity modified ISO cured with the help of accelerator – 1100 and catalyst–1100 is performing better with MWCNT and other Nano materials for the toughness of the coating surface.

Scratch hardness test

In order to analyze the hardness of the various Nano-composites applied on the mild steel surface, scratch hardness test was conducted. Scratch hardness describes the resistance of material surface to plowing by a tough stylus. The hardness test results of various Hybrid Nano composite and neat resins coated mild steel specimens are shown in Figure 26.

Figure 26.

Scratch hardness of various hybrid nano composite and neat resins coated mild steel specimens.

The sample covered with polyurethane resin had the highest scratch hardness (800 mg) among the plain resins, while the sample coated with epoxy resin had the second-highest scratch hardness (700 mg). When compared to pure mild steel samples, samples coated with polyester and phenol resin exhibited the least amount of hardness increase (300 mg). Because the polymer layer utilized here can shield the base material from weathering, abrasion, corrosion, and other processes that would prevent the material from deteriorating over time, the polyurethane resin coated samples produced the highest scratch hardness results.

The scratch hardness of combination MSPS3 shows 400 mg, followed by MSE3 with 900 mg, MGPH1 combination exhibits600 mg of scratch hardness, MZPU2 shows 600 mg of scratch hardness, combination MSPU3 with 400 mg, composite MCE1 with 800 mg, MCPH2 combination with 300 mg of scratch hardness, MGPS4 with least scratch hardness of 200 mg, The combination MZE1 and MZPS2 showing 500 mg of scratch hardness. The combination MSE3 with 900 mg is showing the highest surface hardness among all the Hybrid Nano composite and neat resins coated mild steel specimens. Epoxy resin is a two- component epoxy clear lacquer, cured with polyamide hardener bonds with Nano particles to give better surface hardness of coating surface.

Morphology

SEM analysis was carried out to analyze the morphological characteristics of mild steel surface for corrosion resistance study. The morphology of various hybrid Nano composites and different types of resin coated mild steel samples before and after corrosion are as depicted in Figure 27. The FESEM pictures of tensile breakage specimens coated with hybrid Nano composites shown in Figure A₁, B_1, C₁, D₁, E₁, F₁, G₁, H₁, I₁ and J₁ indicates the continuous application of magnetic stirring and ultrasonication provides uniform distribution of MWCNT’s and the 2^ndNano particles in the resin. Many of the composites have shown clusters of nano particles. The MSPS3 and MZPU2 combination have revealed minimal cluster formation.

Figure 27.

FESEM images of samples coated with MSPS (A1) and (A2) before and after corrosion, MSE (B1) and (B2) after corrosion, MGPH (C1) and (C2) after corrosion, MZPU (D1) and (D2) after corrosion, MSPU (E1) and (E2) after corrosion, MCE (F1) and (F2) before and after corrosion, MCPH (G1) and (G2) after corrosion, MGPS (H1) and (H2) after corrosion, MZE (I1) before corrosion and (I2) after corrosion, MZPS (J1) and (J2) after corrosion, Polyurethane resin (K1) before and (K2) after corrosion, Epoxy resin (L1) before and (L2) after corrosion, Polyester resin (M1) before and (M2) after corrosion, Phenolic resin (N1) before and (N2) after corrosion.

The FESEM images of samples coated with MSPS both before and after the corrosion are shown in Figure 27(A1) and (A2). The images of the polyurethane resin’s FESEM before and after the mild steel samples were exposed to corrosion are displayed in Figure 27(K1) and (K2). The corrosion produced on the surface is shown in Figure 27(K2). Pictures of samples covered with epoxy resin are displayed in Figure 27(L1) and (L2). The mild steel surface has been effectively preserved by epoxy resin, as seen in Figure 27(L2), with very little surface rust. Polyester resin coated samples are shown in Figure 27(M1) and (M2) before and after oxidization, with Figure 27(M2) showing minimal corrosion. It’s also important to note that the mild steel sample coated with phenolic resin showed signs of rusting earlier after corrosion exposure (Figure 27(N1)) than it did previously (Figure 27(N2)). When compared to other plain resins and hybrid nano composites, it is evident that the mild steel samples coated with epoxy resin (Figure 27(L2)), MSPS (Figure 27(A2)), and MZPS (Figure 27(J2)) exhibited the least amount of corrosion. The ultimate tensile strength and corrosion resistance test results, which showed that mild steel specimens coated with epoxy resin produced the best results, are consistent with the morphological results.

Conclusions

To summarize, the study’s findings are as follows:

• Samples of mild steel covered with plain epoxy resin showed excellent corrosion resistance. Since epoxy resin FINECOAT-EP 200 is a two-component epoxy clear lacquer, cured with polyamide hardener, coated samples showed superior results in comparison with the polyurethane, polyester, and phenolic resins.

• There was a notable increase in the rate of tensile strength of mild steel specimens coated with the epoxy resin compared with other resins like polyurethane, polyester, and phenolic resins compared to bare mild steel sample. Epoxy resin is the best material to coat the surface of mild steel in order to prevent corrosion and improve mechanical qualities. It exhibits a 97% corrosion resistance, around 700 mg of surface hardness, and a 10% increase in tensile strength.

• The presence of acrylic polyol and isocyanate allowed the neat polyurethane resin coated mild steel specimen to yield a greater scratch hardness when compared to other mild steel specimens. Better hardness is produced on the coated surface as a result. On the other hand, compared to the neat epoxy coated samples, there is poorer corrosion resistance and tensile property.

• The existence of Resin, MWCNT’s and 2nd Nano particles together shows enhanced properties of both anticorrosion as well as the mechanical properties when compared to the plain mild steel and neat resin samples.

• The hybrid nano composite combinations like Silicon Oxide Nano particle, Graphenenano particles and Zinc Oxide nano particles with MWCNT’s and Polyester resin, Phenolic resin, Polyurethane resin (MSPS3, MGPH1 and MZPU2) has shown the highest values for corrosion resistance and mechanical properties.

• The combination MSPS3 containing Polyester resin FINESTER - 1100 is a medium viscosity modified ISO link stronger with MWCNT’s and Silicon Oxide Nano Particles giving highest of all the combination values of 89% corrosion resistance, 400 mg of surface scratch hardness and 25% increased tensile strength.

• Since, MZPU2 consisting of Polyurethane is a two-component composition based on acrylic polyol and isocyanate bonds better with combination of MWCNT’s with Zinc Oxide Nano particles shows the second highest result of 80% corrosion resistance, 25% increased tensile strength with 600 mg of surface hardness.

• The group MGPH1 which has phenolic resin INSUFINE^®-VI 610 is an impregnating varnish based on alkyd attach well with MWCNT’s and Silicon Oxide Nano Particles giving third highest values of 69% anticorrosion, 600 mg of scratch hardness and 27% rise in tensile strength.

• FESEM analysis shows the samples coated with neat epoxy resin, MSPS3 and MZPS2 observed to have the least corroded surface compared with the other neat resins and hybrid nano resin composite coated mild steel surfaces.

The above conclusion shows that resins have been better surface coating for corrosion resistance. But, the tensile strength of resin coated specimens shows reduced value compared with hybrid nano composite coated specimens.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Janaki Ramulu Perumalla

References

Gupta

Malviya

Verma

, et al. Aminoazobenzene and diaminoazobenzene functionalized graphene oxides as novel class of corrosion inhibitors for mild steel: experimental and DFT studies. Mater Chem Phys 2017; 198: 360–373.

Beltram

Hierarchical materials for energy and environmental applications. University of Trieste: Italy, 2017. PhD dissertation .

Shahriary

Ghourchian

Athawale

. Graphene-multiwalled carbon nanotube hybrids synthesized by gamma radiations: application as a glucose sensor. Journal of Nanotechnology. 2014; 2014(1): 1–10.

Salman

Leman

Sultan

, et al. Ballistic impact resistance of plain woven kenaf/aramid reinforced polyvinyl butyral laminated hybrid composite. Bioresources 2016; 11(3): 7282–7295.

Cheng

. Synthesis and characterization of poly (o-ethoxyaniline)/nano silica composite and study of its anticorrosion performance. Int J Electrochem Sci. 2018; 13(1): 196–208.

Srivastava

. Enhancement of elastic modulus of epoxy resin with carbon nanotubes. World J Nano Sci Eng 2011; 01(1): 1–6.

Eivaz Mohammadloo

Mirabedini

Pezeshk-Fallah

. Microencapsulation of quinoline and cerium-based inhibitors for smart coating application: anti-corrosion, morphology and adhesion study. Prog Org Coating 2019; 137, 105339.

Azammi

Sapuan

Ishak

, et al. Physical and damping properties of kenaf fibre filled natural rubber/thermoplastic polyurethane composites. Defence Technology 2020; 16(1): 29–34.

Taheri

Jam

Beni

, et al. +e effect of service temperature on the impact strength and fracture toughness of GTD-111 superalloy. Eng Fail Anal 2021; 127: 105507.

10.

Bera

Rout

Udayabhanu

, et al. Waterbased & eco-friendly epoxy-silane hybrid coating for enhanced corrosion protection & adhesion on galvanized steel. Prog Org Coating 2016; 101: 24–44.

11.

Chee

Jawaid

Sultan

MTH

, et al. Effects of nanoclay on physical and dimensional stability of bamboo/kenaf/nanoclay reinforced epoxy hybrid nanocomposites. J Mater Res Technol 2020; 9(3): 5871–5880.

12.

Khun

Frankel

. Cathodic delamination of polyurethane/multiwalled carbon nanotube composite coatings from steel substrates. Prog Org Coating 2016; 99: 55–60.

13.

Davoodi

Honarbakhsh

Farzi

. Evaluation of corrosion resistance of polypyrrole/functionalized multiwalled carbon nanotubes composite coatings on 60Cu-40Zn brass alloy. Prog Org Coating 2015; 88: 106–115.

14.

Kumar

Ghosh

Yadav

, et al. Thermo-mechanical and anti-corrosive properties of MWCNT/epoxy nanocomposite fabricated by innovative dispersion technique”, Composites Part B 2017; 113: 291–299.

15.

Mariam

Afendi

Majid

, et al. Influence of hydrothermal ageing on the mechanical properties of an adhesively bonded joint with different adherends. Compos B Eng 2019; 165: 572–585.

16.

Shen

Feng

Liu

, et al. Multiwall carbon nanotubes-reinforced epoxy hybrid coatings with high electrical conductivity and corrosion resistance prepared via electrostatic spraying. Prog Org Coating 2016; 90: 139–146. DOI: 10.1016/j.porgcoat.2015.10.006.

17.

Pourhashem

Vaezi

Rashidi

, et al. Exploring corrosion protection properties of solvent based epoxy-graphene oxide nanocomposite coatings on mild steel. Corrosion Sci 2017; 115: 78–92.

18.

Ramezanzadeh

Ghasemi

Mahdavian

, et al. Covalently-grafted graphene oxide nanosheets to improve barrier and corrosion protection properties of polyurethane coatings. Carbon 2015; 93: 555–573.

19.

Talo

Passiniemi

Fors´en

, et al. Polyaniline/epoxy coatings with good anti-corrosion properties. Synth Met 1997; 85(1): 1333–1334.

20.

Yang

Wang

, et al. Preparation and properties of three-dimensional graphene/phenolic resin composites via in-situ polymerization in graphene hydrogels. Appl Surf Sci 2018; 447: 837–844.

21.

Christopher

Anbu Kulandainathan

Harichandran

. Comparative study of effect of corrosion on mild steel with waterborne polyurethane dispersion containing graphene oxide versus carbon black nanocomposites. Prog Org Coating 2015; 89: 199–211.

22.

Kabaoglu

Karabork

Balun Kayan

, et al. Improvement of anti-corrosion performance (surface and near the cut edge) and mechanical properties of epoxy coatings modified with nano, micro and hybrid ZnO particles. J Compos Mater 2023; 57(3): 451–463.

23.

Bery

Xavier

. A study on the anticorrosion performance of epoxy nanocomposite coatings containing epoxy-silane treated nanoclay on mild steel in chloride environment. J Polym Res 2021; 28(5): 189.

24.

Xavier

. Influence of surface modified mixed metal oxide nanoparticles on the electrochemical and mechanical properties of polyurethane matrix. Front Chem Sci Eng 2023; 17(1): 1–14.

25.

Xavier

Bhaskar

Subramanian

. Multifunctional graphitic carbon nitride/manganese dioxide/epoxy nanocomposite coating on steel for enhanced anticorrosion, flame retardant, mechanical, and hydrophobic properties. J Ind Eng Chem 2024; 134: 514.

26.

Liu

. Effects of modified multi-walled carbon nanotubes on the curing behavior and thermal stability of boron phenolic resin. Polym Degrad Stabil 2009; 94(11): 1972–1978.

27.

Song

Chung

Kim

. The mechanical and thermal characteristics of phenolic foams reinforced with carbon nanoparticles. Compos Sci Technol 2014; 103: 85–93.

28.

Bahlakeh

Ramezanzadeh

. Cerium oxide nanoparticles influences on the binding and corrosion protection characteristics of a melamine-cured polyester resin on mild steel: an experimental, density functional theory and molecular dynamics simulation study. Corrosion Sci 2017; 118: 69–83.

29.

Mostafa

Ismarrubie

Sapuan

, et al. Effect of equi-biaxially fabric prestressing on the tensile performance of woven E-glass/polyester reinforced composites. J Reinforc Plast Compos 2016; 35(14): 1093–1103.

Investigating the improvements in morphometric and mechanical properties of mild steel coated with polymer-based hybrid nano composites

Abstract

Keywords

Introduction

Materials and experimental methodology

Nano materials and their details

Resins selected for fabrication

Experimental procedure

Field emission scanning electron microscopy studies

Corrosion analysis

Immersion test

Salt spray test

Mechanical properties

Tensile strength test

Scratch hardness test

Specimen preparation

The preparation of MWCNTs +2nd nanoparticles composite

Preparation of MWCNT’s + 2nd nanoparticles + resin composites

Result and discussion

Corrosion properties of resin coating

Tensile strength test (A370:2017)

Toughness test

Scratch hardness test

Morphology

Conclusions

Footnotes

Declaration of conflicting interests

Funding

ORCID iD

References

The preparation of MWCNTs +2^nd nanoparticles composite

Preparation of MWCNT’s + 2^nd nanoparticles + resin composites