New Imidazolium Ionic Liquids from Recycled Polyethylene Terephthalate Waste for Curing Epoxy Resins as Organic Coatings of Steel

Imidazolium ionic liquid (IIL) was prepared from aminolysis of polyethylene terephthalate (PET) waste with pentaethylenehexamine (PEHA) to apply as hardener of epoxy resin. Its purified chemical structures, thermal stability, and thermal characteristics were identified as well as amino phthalamide aminolyzed products. The thermal, thermomechanical, and mechanical properties of the cured epoxy resins with different weight percentages of IIL were investigated to optimize the best weight ratio to obtain homogeneous networks. The adhesion, durability, and corrosion resistance of the cured epoxy resins on the steel surfaces were tested to confirm that the best weight ratio of epoxy: IL was 2:1. This ratio achieved higher adhesion strength and salt spray resistance to seawater extended to 1500 h.

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Curing of Functionalized Superhydrophobic Inorganic/Epoxy Nanocomposite and Application as Coatings for Steel

Coatings ◽

10.3390/coatings11010083 ◽

2021 ◽

Vol 11 (1) ◽

pp. 83

Author(s):

Mohamed H. Wahby ◽

Ayman M. Atta ◽

Yasser M. Moustafa ◽

Abdelrahman O. Ezzat ◽

Ahmed I. Hashem

Keyword(s):

Adhesion Strength ◽

Lattice Structure ◽

Salt Spray ◽

Contact Angles ◽

Inorganic Nanoparticles ◽

Crystalline Lattice ◽

Epoxy Coatings ◽

Epoxy Networks ◽

Chemical Structures ◽

Steel Surfaces

Superhydrophobic epoxy nanocomposites coatings with superior mechanical and adhesion strength are targeted to increase epoxy coating performance and to protect steel corrosion in aggressive environment. The present work prepared hydrophobic organic modified inorganic nanoparticles (NPs) based on magnetite, titanium dioxide and silver capped with epoxide oleic, linoleic and linolenic fatty acids. Their chemical structures, thermal stability, crystalline lattice structure, morphology and particles sizes distribution were determined using different tools. The curing exothermic reactions and thermal mechanical properties of the cured commercial epoxy with polyamine hardener were evaluated in the presence of the modified NPs to investigate their effect on the curing mechanism and crosslinking densities of the cured epoxy networks. The adhesion strength, abrasion resistance, seawater contact angles and seawater salt spray resistances of the cured epoxy coatings were evaluated on the steel surfaces. The obtained results confirm that the increasing weight contents of the modified NPs embedded into epoxy networks via chemical linking affect the adhesion, superhydrophobicity and anticorrosion performances of the cured epoxy coatings on the steel surfaces.

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Organic coatings based on new Schiff base epoxy resins

Progress in Organic Coatings ◽

10.1016/j.porgcoat.2013.02.017 ◽

2013 ◽

Vol 76 (7-8) ◽

pp. 1040-1045 ◽

Cited By ~ 17

Author(s):

Sylwia Waśkiewicz ◽

Klaudia Zenkner ◽

Ewa Langer ◽

Marta Lenartowicz ◽

Izabela Gajlewicz

Keyword(s):

Schiff Base ◽

Epoxy Resins ◽

Organic Coatings

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An artificial neural network prediction on physical, mechanical, and thermal characteristics of giant reed fiber reinforced polyethylene terephthalate composite

Journal of Industrial Textiles ◽

10.1177/15280837211064804 ◽

2021 ◽

pp. 152808372110648

Author(s):

Arpitha Gulihonenahali Rajkumar ◽

Mohit Hemath ◽

Bharath Kurki Nagaraja ◽

Shivakumar Neerakallu ◽

Senthil Muthu Kumar Thiagamani ◽

...

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Flexural Strength ◽

Polyethylene Terephthalate ◽

Flexural Modulus ◽

Thermal Characteristics ◽

Giant Reed ◽

Fiber Reinforced ◽

Fiber Concentration ◽

Artificial Neural

Plant fiber reinforced hybrid polymer composites have had broad applications recently because of their lower cost advantages, lower weight, and biodegradable nature. The present work studies the influence of reinforcing giant reed fiber concentration in polyethylene terephthalate (PET) polymer for their physical, mechanical, and thermal characteristics and determines the optimum loading of giant reed fiber using an artificial neural network (ANN) scheme. Giant reed fiber reinforced PET matrix laminates were manufactured from compression molding with different fiber loadings such as 5 wt.%, 10 wt.%, and 20 wt.%. The mechanical characteristics such as tensile and flexural strength and the laminate’s tensile and flexural modulus were appraised and examined. The maximum value of tensile strength, flexural strength, tensile modulus, and flexural modulus were 5.4 MPa, 26 MPa, 8343 MPa, and 6300 MPa, respectively, for PET2 (10 wt.% of giant reed fiber in PET polymer) composite. Fiber pullout, gaps, and fracture behavior were examined from a scanning electron microscope in the microstructural analysis. A machine learning technique has been recommended to combine artificial intelligence while designing giant reed fiber reinforced polymeric laminates. Using the suggested method, an ANN model has been generated to attain the targeted giant reed fiber concentration for PET composite while gratifying the necessary targeted characteristics. The developed method is very effective and decreases the effort and time of material characterization for huge specimens. It will support the researchers in designing their forthcoming test efficiently.

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Synthesis of MOF-5 using terephthalic acid as a ligand obtained from polyethylene terephthalate (PET) waste and its test in CO2 adsorption

Brazilian Journal of Chemical Engineering ◽

10.1007/s43153-021-00192-5 ◽

2022 ◽

Author(s):

D. Villarroel-Rocha ◽

M. C. Bernini ◽

J. J. Arroyo-Gómez ◽

J. Villarroel-Rocha ◽

K. Sapag

Keyword(s):

Polyethylene Terephthalate ◽

Terephthalic Acid ◽

Co2 Adsorption ◽

Pet Waste

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New epoxy resins based on recycled poly(ethylene terephthalate) as organic coatings

Progress in Organic Coatings ◽

10.1016/j.porgcoat.2006.11.001 ◽

2007 ◽

Vol 58 (1) ◽

pp. 13-22 ◽

Cited By ~ 43

Author(s):

Ayman M. Atta ◽

Ahmed F. El-Kafrawy ◽

Morsy H. Aly ◽

Abdel-Azim A. Abdel-Azim

Keyword(s):

Epoxy Resins ◽

Ethylene Terephthalate ◽

Organic Coatings ◽

Poly Ethylene Terephthalate ◽

Poly Ethylene

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Extraction Optimization, Structural Characterization, and Antioxidant Activities of Polysaccharides from Cassia Seed (Cassia obtusifolia)

Molecules ◽

10.3390/molecules24152817 ◽

2019 ◽

Vol 24 (15) ◽

pp. 2817 ◽

Cited By ~ 7

Author(s):

Ding-Tao Wu ◽

Wen Liu ◽

Qiao-Hong Han ◽

Ping Wang ◽

Xian-Rong Xiang ◽

...

Keyword(s):

Functional Food ◽

Antioxidant Activities ◽

Radical Scavenging ◽

Weight Ratio ◽

Reducing Power ◽

Natural Antioxidants ◽

Hot Water ◽

Raw Material ◽

Food Ingredients ◽

Chemical Structures

In order to explore Cassia seed polysaccharides (CSPs) as natural antioxidants for application in the functional-food industry, microwave-assisted extraction (MAE) was optimized for the extraction of CSPs by using a response surface methodology. Furthermore, the chemical structures and antioxidant activities of CSPs extracted by MAE and hot water extraction were investigated and compared. The maximum extraction yield of CSPs extracted by MAE (8.02 ± 0.19%) was obtained at the optimized extraction parameters as follows: microwave power (415 W), extraction time (7.0 min), and ratio of water to raw material (51 mL/g). Additionally, the contents of the uronic acids, molecular weight, ratio of constituent monosaccharides, intrinsic viscosities, and degrees of esterification of CSPs were significantly affected by the MAE method. Moreover, CSPs exhibited remarkable 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ABTS, 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl DPPH, nitric oxide, and hydroxyl radical scavenging activities as well as reducing power. The high antioxidant activities observed in CSPs extracted by MAE could be partially attributed to its low molecular weights and high content of unmethylated galacturonic acid. Results indicate that the MAE method could be an efficient technique for the extraction of CSPs with high antioxidant activity, and CSPs could be further explored as functional food ingredients.

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The corrosion protection of AA2024-T3 aluminium alloy by leaching of lithium-containing salts from organic coatings

Faraday Discussions ◽

10.1039/c4fd00237g ◽

2015 ◽

Vol 180 ◽

pp. 511-526 ◽

Cited By ~ 42

Author(s):

Peter Visser ◽

Yanwen Liu ◽

Xiaorong Zhou ◽

Teruo Hashimoto ◽

George E. Thompson ◽

...

Keyword(s):

Electron Microscopy ◽

Salt Spray ◽

Protective Layer ◽

Middle Layer ◽

Organic Coating ◽

Organic Coatings ◽

Inhibition Mechanism ◽

Dense Layer ◽

Neutral Salt ◽

Protective Layers

Lithium carbonate and lithium oxalate were incorporated as leachable corrosion inhibitors in model organic coatings for the protection of AA2024-T3. The coated samples were artificially damaged with a scribe. It was found that the lithium-salts are able to leach from the organic coating and form a protective layer in the scribe on AA2024-T3 under neutral salt spray conditions. The present paper shows the first observation and analysis of these corrosion protective layers, generated from lithium-salt loaded organic coatings. The scribed areas were examined by scanning and transmission electron microscopy before and after neutral salt spray exposure (ASTM-B117). The protective layers typically consist of three different layered regions, including a relatively dense layer near the alloy substrate, a porous middle layer and a flake-shaped outer layer, with lithium uniformly distributed throughout all three layers. Scanning electron microscopy and white light interferometry surface roughness measurements demonstrate that the formation of the layer occurs rapidly and, therefore provides an effective inhibition mechanism. Based on the observation of this work, a mechanism is proposed for the formation of these protective layers.

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Effects of Silanes on the Structure and Properties of Chromium-Free Passivation

Science of Advanced Materials ◽

10.1166/sam.2020.3750 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1012-1018

Author(s):

Fu Haiyang ◽

Gao Bo ◽

Zhou Yingwei ◽

Xing Pengfei

Keyword(s):

Photoelectron Spectroscopy ◽

Film Formation ◽

Resin Composite ◽

Salt Spray ◽

Neutral Salt ◽

Silane Coupling Agents ◽

Passivation Film ◽

White Rust ◽

Steel Surfaces ◽

Corrosion Of Steel

Steel is one of the most widely used metal materials, and corrosion of steel surfaces is a serious problem. Traditional chromate passivation produces hexavalent chromium with high toxicity and carcinogenicity. To solve toxicity and pollution problems, a chromium-free passivation method was adopted to replace the traditional process. Based on the reaction mechanisms of some silane coupling agents, a new method of chromium-free passivation and anti-white rust production is presented in this paper. The chromium-free passivation process of an inorganic material-silane-resin composite was used in the study. The microstructure and corrosion resistance of a hot-dip galvanized sheet and silane passivation film were compared by using a neutral salt spray test, scanning electron microscopy, infrared spectroscopy and X-ray photoelectron spectroscopy. The mechanism of film formation was studied. The results show that the surface of the passivation film is dense and smooth without sharp protrusions and has a stable skeleton structure inside. The structure of the passive film is C=O, Si–O, C–Si, C–H, Si–O–Zn, Si–O–Si, etc. A chromium-free passivation film prepared with a disilane can effectively prevent penetration between the corrosive medium and matrix. After a 96 h corrosion test, the corrosion area is less than 5%, which meets the requirements of some industrial production processes.

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