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1 – 10 of 288Nikita Mhadeshwar, Kunal Wazarkar and Anagha S. Sabnis
This paper aims to prepare acrylic functional ricinoleic acid monomer and incorporate it in conventional miniemulsion polymerization. Subsequently, paints were formulated to study…
Abstract
Purpose
This paper aims to prepare acrylic functional ricinoleic acid monomer and incorporate it in conventional miniemulsion polymerization. Subsequently, paints were formulated to study the variation in final coating properties.
Design/methodology/approach
Synthesis process involved the esterification of ricinoleic acid with 2-hydroxy methyl methacrylate in the presence of FASCAT-4100 catalyst. The final product of the reaction, methacrylated ricinoleic acid (MRA), was confirmed using Fourier-transform infrared spectroscopy and 1H-nuclear magnetic resonance spectroscopy and determining acid and iodine value. Further, MRA was incorporated in various concentrations (1, 2 and 3 Wt.%) along with methyl acrylate and butyl acrylate in conventional miniemulsion polymerization and paints were formulated thereof.
Findings
It was observed that with the addition of MRA monomer, flexibility of emulsion films increased as indicated by glass transition temperature and elongation value (percentage). Moreover, with the addition of MRA monomer, improvement in mechanical and chemical properties of the coatings was observed.
Research limitations/implications
Even a low concentration MRA monomer (as low as 3 per cent) caused a significant reduction in the glass transition temperature of emulsion films. Thus, it can be efficiently used in applications such as adhesives and elastomeric coatings.
Originality/value
The acrylic functional monomer derived from ricinoleic acid is unique and not yet incorporated in miniemulsion polymerization. The synthesized monomer can be used in coatings where low Tg emulsions are required.
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V.D. Athawale and R.V. Nimbalkar
The purpose of this paper is to develop a volatile organic component‐free water‐based binder with improved coating properties from urethane‐alkyd acrylate by emulsion…
Abstract
Purpose
The purpose of this paper is to develop a volatile organic component‐free water‐based binder with improved coating properties from urethane‐alkyd acrylate by emulsion polymerisation.
Design/methodology/approach
Alkyd resin based on interesterification of sardine fish and linseed oil (50:50 w/w) was synthesised and reacted with isophorone diisocyanate to form urethane alkyd. The resultant urethane alkyd and acrylic monomers in different ratios were polymerised by emulsion polymerisation to form air‐drying water‐based binders and studied for physicochemical and other coating properties.
Findings
Urethane alkyd, co‐polymerised with acrylates by emulsion polymerisation process, can be used to prepare water‐based air‐drying binders with excellent coating and application performance. The increase in acrylate component in the system resulted in improvement of performance properties.
Research limitations/implications
In the present study, refined fish oil (FO) was obtained from sardine fish. Different FOs can be used to produce alkyd resin. Urethane alkyd and acrylic monomers in different ratios can be polymerised by emulsion polymerisation techniques.
Practical implications
The emulsion polymerisation is the most effective technique used to produce water‐based binders with excellent coating properties.
Originality/value
Water‐based binders can be widely used in exterior coatings and waterproofing of cement and roofs.
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Abstract
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An introduction to the topic of aqueous silicone resin coating systems for exterior masonry. Concentrates on applications in the construction industry.
Abstract
An introduction to the topic of aqueous silicone resin coating systems for exterior masonry. Concentrates on applications in the construction industry.
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Abstract
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The science of the paint industry has never been more highly developed than it is today. Yet there has never been a time when it is necessary to develop more basic information to…
Abstract
The science of the paint industry has never been more highly developed than it is today. Yet there has never been a time when it is necessary to develop more basic information to solve the difficult technical problems that face the coatings industry.
Yuanfeng Jia, Nana Ren, Huadong Yue, Jianru Deng and Yali Liu
The paper developed a novel gallic acid-based rust conversion emulsion (RCE) that is applied in the treatment of rusted steels. The purpose of this paper is to investigate the…
Abstract
Purpose
The paper developed a novel gallic acid-based rust conversion emulsion (RCE) that is applied in the treatment of rusted steels. The purpose of this paper is to investigate the methods for the synthesis of RCE and study the mechanism of rust conversion.
Design/methodology/approach
Conversion emulsion was prepared using styrene, acrylate and self-developed gallic acid (GA)-based rust converter (GRC) via seed emulsion polymerisation. The polymerisable GRC was synthesised by the ring-opening reaction of glycidyl methacrylate with natural GA. The effects of the GRC dosage and its feeding modes on the RCE synthesis were analysed. The corrosion resistance, surface morphology, composition and mechanism of rust conversion coatings were studied using electrochemical tests, scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), respectively.
Findings
The results showed that conversion coating on rusted steels treated with RCE, with various dosages of GRC (weight per cent), synthesised using seed emulsion polymerisation, exhibited the best adhesion and corrosion resistance. Raman spectroscopy revealed that RCE converted the original multiphase rust into stable crystalline phases of α-Fe2O3 and Fe3O4. According to XPS and energy dispersive X-ray analysis, the phenolic hydroxyl groups of RCE were proposed to chelate with Fe ions to form macromolecular ferrum compounds.
Research limitations/implications
The pre-rusted steels demonstrated a better corrosion resistance than rust-free steels after treatment with RCE.
Practical implications
The paper developed a novel GA-based RCE with high efficiency and environment-friendly method.
Originality/value
This work is expected to replace the conventional rust conversion paints and cause a significant impact on extending the service life of rusted steels.
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L.M. Quej-Ake, A. Contreras and Jorge Aburto
The purpose of this research is to study different extra-heavy crude oil-in-water emulsions that can be found in practice for corrosion process of X52 steel adding 60 mg.L-1 of…
Abstract
Purpose
The purpose of this research is to study different extra-heavy crude oil-in-water emulsions that can be found in practice for corrosion process of X52 steel adding 60 mg.L-1 of non-ionic surfactant and a corrosion inhibitor (CI). Electrochemical impedance spectroscopy and Tafel plots are carried out. Thus, Bode-modulus and Bode-phase angle plots are discussed. Adsorption isotherms obtained from corrosion rate (CR) values are taken into account.
Design/methodology/approach
Two-electrode arrangement is used to characterize the pseudo-capacitance values for X52 steel exposed to water and crude oil phases, mainly. Electrochemical evaluations for X52 steel exposed to extra-heavy crude oil-in-water emulsions are recorded in a conventional three-electrode cell to study the corrosion process as was documented in detail by Quej-Ake et al. (2015). Therefore, all electrodes are placed as close as possible to eliminate the iR-drop.
Findings
Pseudo-capacitance analysis shows that X52 steel immersed in oilfield produced water was more susceptible to corrosion than that immersed in ocean water solution and extra-heavy crude oil phase. After being analyzed, the X52 steel surface coverage and adsorption process for surfactant and CI could be concluded that surfactant could protect the metal surface. In a coalescence extra-heavy crude oil-in-water emulsion, the water medium generated a new solution that was more corrosive than the original water phase. Wash crude oil process was provoked in emulsion systems to sweep up the salts, mainly. Thus, corrosive species that can be recovered inside extra-heavy crude oil may appear, and in turn a new more corrosive solution could be obtained. Taking into account the straight line obtained in Bode-modulus plot for X52 exposed to extra-heavy crude oil, it is possible to point out that the negative value of the slope or R2 can be related to a coefficient (Jorcin et al., 2006). It is important to mention that electrochemical responses for X52 steel exposed to extra-heavy crude oil-in-water under coalescence emulsions revealed that corrosion and diffusion processes exist. Therefore, a possible good inhibitor is surfactant in emulsion systems.
Originality/value
CR and anodic and cathodic slopes suggest that the surfactant acted as mixed CI. Of these, susceptible anodic (MnS and perlite or cementite) and cathodic (ferrite) sites on steel surface could be affected, due to which physicochemical adsorption could happen by using electrochemical parameters analysis. Thus, no stable emulsions should be taken into account for extra-heavy crude oil transportation, because corrosion problems in atmospheric distillation process of the crude oil due to stable emulsion cannot be easily separated. In this manner, coalescent emulsions are more adequate for transporting extra-heavy crude oil because low energy to separate the water media is required.
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Jia Lu, Allan J. Easteal and Neil R. Edmonds
The purpose of this paper is to enhance the water resistance and the heat resistance of poly(vinyl acetate) (PVAc) emulsion adhesive, by providing the emulsion with controllable…
Abstract
Purpose
The purpose of this paper is to enhance the water resistance and the heat resistance of poly(vinyl acetate) (PVAc) emulsion adhesive, by providing the emulsion with controllable thermosetting capability.
Design/methodology/approach
Emulsion polymerisation was used to synthesise PVAc/VeoVa 10 copolymers with varying proportions of acetoacetoxyethyl methacrylate (AAEM) incorporated in the copolymer chains. The AAEM component provided sites for crosslinking the chains via reaction of diamines with AAEM. The emulsion copolymers formed crosslinked films on addition of a range of diamines, during drying at ambient temperature. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterise the copolymerisation and crosslinking reaction. Glass transition temperatures of the polymer films were measured using dynamic mechanical thermal analysis to quantify the effects of copolymer composition variation and crosslinker. The performance of the crosslinked emulsions as wood adhesives was evaluated in accordance with the ISO 6238 standard by measuring the maximum shear stress of wood joints.
Findings
The crosslinking reaction between acetoacetoxy groups in the copolymer chains and the added diamines gives enamine structures, and occurs rapidly at ambient temperature. Major changes in the 13C NMR spectrum include the appearance of an enamine signal at 82 ppm, and disappearance of the acetoacetoxy carbonyl signal at 202 ppm. The new vibrational band at 1,597‐1,606 cm−1 in the FTIR spectrum is assigned to the vibrations of the enamine double bond. The experimental results showed substantial increases in Tg and viscosity as the AAEM proportion in the copolymer emulsion increased. The crosslinked adhesives showed superior wood adhesive performance to unmodified PVAc emulsion.
Research limitations/implications
It was necessary to adjust the pH of the emulsion for extended shelf life.
Practical implications
The method developed provides a simple and practical route to emulsions with improved water and heat resistance and bonding strength.
Originality/value
The method for enhanced water and heat resistance of PVAc wood adhesive was novel, straightforward and environmental friendly.
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Youssef L. Nashed, Fouad Zahran, Mohamed Adel Youssef, Manal G. Mohamed and Azza M. Mazrouaa
The purpose of this study is to examine how well reinforced concrete structures can be shielded against concrete carbonation using anti-carbonation coatings based on synthetic…
Abstract
Purpose
The purpose of this study is to examine how well reinforced concrete structures can be shielded against concrete carbonation using anti-carbonation coatings based on synthetic polymer.
Design/methodology/approach
Applying free radical polymerization, an acrylate terpolymer emulsion that a surfactant had stabilized was created. A thermogravimetric analysis, minimum film-forming temperature, Fourier transform infrared spectroscopy and particle size distribution are used to characterize the prepared eco-friendly water base acrylate terpolymer emulsion. Using three different percentages of the acrylate terpolymer emulsion produced, 35%, 45% and 55%, the anti-carbonation coating was formed. Tensile strength, tensile strain, elongation, crack-bridging ability, carbon dioxide permeability, chloride ion diffusion, average pull-off adhesion strength, water vapor transmission, gloss, wet scrub resistance, QUV/weathering and storage stability are the characteristics of the anti-carbonation coating.
Findings
The formulated acrylate terpolymer emulsion enhances anti-carbonation coating performance in CO2 permeability, Cl-diffusion, crack bridging, pull-off adhesion strength and water vapor transmission. The formed coating based on the formulated acrylate terpolymer emulsion performed better than its commercial counterpart.
Practical implications
To protect the steel embedded in concrete from corrosion and increase the life span of concrete, the surface of cement is treated with an anti-carbonation coating based on synthetic acrylate terpolymer emulsion.
Social implications
In addition to saving lives from building collapse, it maintains the infrastructure for the long run.
Originality/value
The anti-carbonation coating, which is based on the synthetic acrylate terpolymer emulsion, is environmentally benign and stops the entry of carbon dioxide and chlorides, which are the main causes of steel corrosion in concrete.
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