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Article
Publication date: 26 August 2014

Zhifeng Huang, Xiaoyang Ma, Zemin Qiao, Shujuan Wang and Xinli Jing

This paper aims to disclose the evolution of pendulum hardness of two-component acrylic polyurethane coatings during the cure process and attempts to describe the…

Abstract

Purpose

This paper aims to disclose the evolution of pendulum hardness of two-component acrylic polyurethane coatings during the cure process and attempts to describe the quantitative relationship between pendulum hardness and curing time. These findings are helpful for the study of fast curing acrylic polyurethane coatings.

Design/methodology/approach

The pendulum hardness method was used to monitor the hardness of two-component acrylic polyurethane coatings during curing. The quantitative relationship between pendulum hardness and curing time can be obtained with Avrami equation.

Findings

The evolution of coating pendulum hardness can be divided into three stages. By using the Avrami equation that explained the influence of both the acid value and the curing temperature on the drying speed of hydroxyl acrylic resin, the evolution of coating pendulum hardness during curing can also be accurately described.

Research limitations/implications

It should be noted that the physical meaning of the Avrami exponent, n, is not yet clear.

Practical implications

The results are of great significance for the development of fast-curing hydroxyl-functional acrylic resins, with the potential to improve the drying speed of the coatings used in automotive refinish.

Originality/value

It is novel to divide the pendulum hardness into three stages, and, for the first time, the Avrami equation is utilized to describe the evolution of coating pendulum hardness during curing.

Details

Pigment & Resin Technology, vol. 43 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 29 June 2012

A.P. Kabra, P. Mahanwar, V. Shertukde and V. Bambole

The purpose of this paper is to formulate two component polyurethane coatings based on acrylic polyol, to study the effects of variable nanosilica loadings in these…

Abstract

Purpose

The purpose of this paper is to formulate two component polyurethane coatings based on acrylic polyol, to study the effects of variable nanosilica loadings in these coatings on different morphological, optical, mechanical, corrosion resistance and weather resistance properties and to study the intercalation of acrylic polyol molecules into nanosilica crystals by XRD technique.

Design/methodology/approach

Two component polyurethane coatings were synthesised using acrylic polyol and isocyanate HDI. The nanosilica was incorporated in polyurethane formulation at the weight ratios of 1%, 3% and 5% based on total weight of polyol and isocyanate. The performance of nanocoatings was compared for variable loads of nanosilica for different properties such as morphological, optical, mechanical, corrosion resistance, weather resistance and were studied for intercalation of acrylic polyol into nanosilica crystals by XRD technique.

Findings

Improvement in the properties of polyurethane coatings is achieved with the incorporation of nanosilica. The improvement is the result of inherently high properties of inorganic nanosilica. Tensile strength, scratch hardness, abrasion resistance, corrosion and weathering resistance show significant improvement in performance with the incorporation of nanosilica. Properties are found to deteriorate beyond a certain loading of nanosilica; hence it is important to optimise loading level. The optimal range for high performance was found to be in the range of 1% to 3%. The improvement was a result of synergistic behaviour and good interfacial interaction between polyurethane and nanosilica at optimal levels.

Research limitations/implications

The method used for incorporation of nanosilica into polyurethane was direct incorporation method. The other method of incorporation, i.e. in situ addition and its effect on properties can also be studied.

Practical implications

With the addition of optimal loading level of nanosilica to polyurethane coatings, properties can be enhanced up to the mark. The addition is relatively easy and cost effective.

Originality/value

The paper proves the significance of incorporation of nanosilica on original properties of polyurethane coatings and widens the area of applications of two component polyurethane coatings from acrylic polyol by strengthening them in their properties. The coatings can be applicable in high performance topcoats especially for automotive topcoats.

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Article
Publication date: 30 August 2013

S. Abhijit, Prakash A. Mahanwar and V.A. Bambole

The aim of this paper is to conduct a real time evaluation of polypyrrole as an anti‐corrosive pigment in epoxy polyamide coating.

Abstract

Purpose

The aim of this paper is to conduct a real time evaluation of polypyrrole as an anti‐corrosive pigment in epoxy polyamide coating.

Design/methodology/approach

This study deals with synthesis of polypyrrole (PPy) by chemical oxidative polymerisation in laboratory conditions. The synthesised PPy was characterised by employing FT‐IR, XRD, SEM and EDX analysis. Epoxy film of bisphenol type hardened with polyamide based curing agent was used as the binder. PPy was used as anti‐corrosive pigment in concentrations varying from 0 to 5 wt% in the coating. In addition to anti‐corrosive property, mechanical, chemical and weathering properties of the coating containing PPy were studied and compared with epoxy polyamide coating without PPy.

Findings

The result obtained through various tests showed that the coating with 1 and 2% PPy exhibited excellent weathering resistance, mechanical properties and improved chemical resistance.

Research limitations/implications

The anti‐corrosion property of the coating can be tested by means of atmospheric exposure such as Florida test or by means of electrochemical impedance spectroscopy.

Practical implications

The results find application in anti‐corrosive paints for industrial application.

Originality/value

This research paper presents the results of anti‐corrosion behaviour of PPy in epoxy‐polyamide coating. Based on this result, a highly effective anti‐corrosive coating can be formulated by addition of small percentage of PPy in combination with other conventional pigments, thereby enhancing corrosion protection.

Details

Pigment & Resin Technology, vol. 42 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 4 November 2013

Prakash Mahanwar, Abhijit Sathyanarayana, Vaishali Bambole and Sunil Sabharwal

– The paper aims to discuss the evaluation of anti-corrosive efficiency of conducting polymer, polypyrrole in water borne epoxy-polyamine coatings.

Abstract

Purpose

The paper aims to discuss the evaluation of anti-corrosive efficiency of conducting polymer, polypyrrole in water borne epoxy-polyamine coatings.

Design/methodology/approach

Polypyrrole (PPy) is synthesised by chemical oxidative polymerisation. The synthesised PPy is characterised by employing FT-IR, XRD, SEM and EDX analysis. The coatings are formulated using water borne epoxy cross-linked with aliphatic polyamine adduct and the effect of PPy on corrosion prevention is studied. PPy was used as anti-corrosive pigment in concentration varying from 1 to 5 wt.%. In addition to anti-corrosive property; mechanical properties, chemical resistance and weathering properties of the coatings containing PPy are studied, thereby obtaining a wholesome data about the quality and performance of these coatings.

Findings

The result obtained through various tests showed that the coating with 1 and 2% PPy exhibited excellent weathering resistance, mechanical properties and improved chemical resistance. Higher percentage loading of PPy (beyond 3 per cent) proves to be disastrous, as extended percolation networks are formed which results in rapid intense corrosion leading to fast coating breakdown.

Research limitations/implications

The anti-corrosion property of the coating can be tested by means of atmospheric exposure such as Florida test which produces a real time evaluation of the anti-corrosive nature of the coating at natural condition rather than accelerated weathering, thereby providing more reliable performance data for intended application purpose.

Practical implications

The results find application in anti-corrosive/performance paints for industrial application.

Originality/value

This research paper presents the results of anti-corrosion behaviour of PPy in water borne epoxy-polyamide coating. Based on this result, a highly effective anti-corrosive coating can be formulated by the addition of small percentage of PPy in combination with other conventional pigments, thereby enhancing corrosion protection. But care must be taken so as to avoid formation of extended percolation network of PPy which leads to rapid coating breakdown.

Details

Pigment & Resin Technology, vol. 42 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 17 July 2020

Gülçin Baysal, Gizem Keleş, Berdan Kalav, F. Seniha Güner and Burçak Karagüzel Kayaoğlu

In this study, it is aimed to synthesize ultraviolet (UV)-curable water-borne polyurethane acrylate (WPUA) binders using different types of polyols (poly (propylene…

Abstract

Purpose

In this study, it is aimed to synthesize ultraviolet (UV)-curable water-borne polyurethane acrylate (WPUA) binders using different types of polyols (poly (propylene glycol), PPG1000 and PPG2000 and poly (ethylene glycol), PEG1000 and PEG2000) at different molecular weights, DMPA (2,2-bis(hydroxymethyl) propionic acid) at different amounts and isophorone diisocyanate (IPDI) and use for pigment printing on synthetic leather.

Design/methodology/approach

UV-cured films were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC). The effect of binder structure on printing performance was determined with hardness, crock fastness, abrasion resistance and color measurements.

Findings

The highest abrasion resistance (60,000 cycles) and crock fastness values (dry crock and wet crock: 3/4) were obtained with binder PEG-C synthesized with PEG2000 and lower DMPA amount of 4.89 wt%; however, PEG-C binder showed lower hardness values. Due to lower urethane groups in PEG-C binder, more flexible films were obtained which imparted good adhesion property to printing film. Synthesized binders provided lower crock fastness and abrasion resistance properties than commercial WPUA binder.

Originality/value

Pigmented formulations including UV-curable water-borne synthesized PUA binder were developed and for the first time applied onto synthetic leather using screen printing method. Within this context, a new environmentally friendly printing method was proposed in this study including binder synthesis in the preparation of printing formulations.

Details

International Journal of Clothing Science and Technology, vol. 33 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 4 September 2017

Zaker Bahreini, Vahid Heydari and Zahra Namdari

Mechanical and chemical properties of acrylic-melamine automotive clear coat in the presence of different percentages of well dispersed nano-layered sodium montmorillonite…

Abstract

Purpose

Mechanical and chemical properties of acrylic-melamine automotive clear coat in the presence of different percentages of well dispersed nano-layered sodium montmorillonite (Na-MMT) silicate particles were investigated. For this purpose, prepared dry clear coat film samples were subjected to the entire standard test series, usually carried out in automotive coating industry.

Design/methodology/approach

Effects of adding different percentages of nano-layered silicate on mechanical and chemical properties of acrylic-melamine automotive clear coat were investigated. To increase the compatibility of nanoclays with polymer matrix of clear coat, the surface of nanoclays was modified by benzalkonium chloride as a cationic surfactant. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used for characterization and comparison between clays before and after modification, and also after dispersion in coating. Prepared dry clear coat film samples subjected to the test series are usually carried out in automotive coating industry.

Findings

The results indicated that incorporation of 1 and 2 Wt.% of nano-layered silicate caused desired improvement in chemical and physical properties of the acrylic-melamine clear coat. Increasing the percentage of nanoclay to over 2 Wt.% caused damage in some properties such as hardness, cupping and gloss.

Research limitations/implications

All materials and methods were used in this research are industrial grade. Therefore, the introduced modified clear coat sample has potential for commercial production as an automotive clear coat.

Originality/value

As far as it was searched in the literature, effects of adding nanoclay particles on mechanical and physical properties of different clear coats, such as epoxy clear coat, have been investigated in a few researches, but in this research, common and special tests which are necessary in automotive coating industry have been ignored. In the present study for the first time, acrylic-melamine clear coat was subjected to modification using nano-clay, and also, the most common industrial test methods were used for investigation of mechanical and chemical properties.

Details

Pigment & Resin Technology, vol. 46 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 20 March 2009

A. Kalendova and D. Vesely

The purpose of this paper is to synthesize MeO‐type pigments, focusing on the oxides containing zinc and magnesium.

Abstract

Purpose

The purpose of this paper is to synthesize MeO‐type pigments, focusing on the oxides containing zinc and magnesium.

Design/methodology/approach

Oxides ZnO and MgO were synthesized, their morphology was evaluated, and their impact on the physical properties of the paint film were assessed. A pigment of ZnO/core‐shell type also was synthesized. The physical‐chemical property of the synthesized pigments and the anticorrosion efficiencies of the paint films pigmented by them were determined. The binder used in the researched coatings was epoxy‐ester resin.

Findings

The shape of the particles was identified in the synthesized pigments. X‐ray diffraction analysis revealed the degree of precipitation and lattice parameters. All of the synthesized pigments had good anticorrosion efficiency in an epoxyester coating.

Practical implications

The synthesized pigments can be used conveniently in coatings protecting metal substrates against corrosion.

Originality/value

Of benefit is the fact that the synthesized pigments do not contain any environmentally harmful substances.

Details

Anti-Corrosion Methods and Materials, vol. 56 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 October 2005

N.M. Ahmed and M.M. Selim

Several solid solution combinations of aluminium oxide and iron oxide, for the preparation of a new pigment, were investigated to study the effect of aluminium oxide to…

Abstract

Purpose

Several solid solution combinations of aluminium oxide and iron oxide, for the preparation of a new pigment, were investigated to study the effect of aluminium oxide to iron oxide ratio on various properties of the resulting pigments.

Design/methodology/approach

The conditions for the preparation of the pigments via solid solution interaction at 1,000°C had been estimated. Characterisation of three different combinations of aluminium oxide and iron oxide were carried out using spectroscopic methods of analysis via X‐ray diffraction (XRD), transmission and scanning electron microscopy (TEM and SEM). Also, evaluation of the pigments prepared, in terms of oil absorption, specific gravity, water‐soluble matter, and pH, using international standard testing methods was performed. The pigments prepared were incorporated in anticorrosive paint formulations based on medium oil alkyd resin as a binder. The physico‐mechanical properties of the relevant paint films were obtained, while their anticorrosive properties were assessed by tests in 3.5 per cent NaCl solution for 28 days.

Findings

The results showed that the anticorrosive protection properties of the pigment prepared were better than their aluminium and iron counterparts.

Research limitations/implications

The pigments prepared may be used in different applications other than paint formulations. As the concentration of iron oxide increases, the hardness and the anticorrosive protection performance of the paint film increase. As the concentration of aluminium increases, elasticity, impact resistance and ductility also increase. Application of different combinations of these pigments in paint films had been studied. However, investigation of the application of these pigments in other systems such as plastics could also be interesting.

Practical implications

The pigments prepared can be used as reinforcing filler in different rubber and plastic composites, beside its ferro‐magnetic properties. As the concentration of alumina increased, the reinforcing and magnetic effects decreased and vice versa.

Originality/value

Iron oxide is an abundant ore in several world countries; it is an inorganic, environmentally friendly material, which exhibits good Moh's hardness. Adding aluminium oxide which is a very light element having a unique flaky structure to iron oxide gave a new pigment that can be used not only in paint formulations, but also in rubber and plastic composites as reinforcing fillers.

Details

Pigment & Resin Technology, vol. 34 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 August 2004

M.A. Abd El‐Ghaffar, E.A.M. Youssef and N.M. Ahmed

Historically, paints designed to protect steel and other metals have been formulated using anticorrosive chromate pigments, which are currently under environmental…

Abstract

Historically, paints designed to protect steel and other metals have been formulated using anticorrosive chromate pigments, which are currently under environmental restrictions. During the investigation reported here, various phosphate compounds. The pigments prepared were characterised using a variety of chemical and spectrophotometric methods of analysis including emission atomic absorption, transmission electron microscope, X‐ray diffraction, in addition to thermal gravimetric analysis. The pigments were also evaluated according to relevant international standard testing methods. The phosphates prepared were incorporated into anticorrosive paint formulations, to replace the imported zinc phosphate pigment, containing medium oil alkyd resin, and melamine formaldehyde resin. Paint films obtained were tested in artificial seawater for 28 days for anticorrosion properties. The results indicated that the paint films had good anticorrosive protection properties that could be attributed to the pigments prepared and the resins used.

Details

Pigment & Resin Technology, vol. 33 no. 4
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 23 March 2010

Nivin M. Ahmed and Mohamed M. Selim

The purpose of this paper is to determine a new easy route to obtain high performance and economic anticorrosive hybrid pigments based on kaolin and ferrite. The new route…

Abstract

Purpose

The purpose of this paper is to determine a new easy route to obtain high performance and economic anticorrosive hybrid pigments based on kaolin and ferrite. The new route is based on depositing a surface layer of an expensive efficient anticorrosive pigment (ferrite) on a bulk of cheap extender pigment (kaolin). The combination of these pigments can add improved properties to the new pigment different from each of its individual components. These improved properties lead to imparting new properties to paint films containing these prepared pigments.

Design/methodology/approach

The new prepared hybrid pigments contain different concentrations of deposited ferrite on kaolin surface, are determined using X‐ray fluorescence analysis to estimate the concentration of each element in the pigments. The pigments are characterised using different spectro‐photometric and analytical methods to prove the deposition of the shell layer and elucidate the structure of their particles. Then, they are incorporated in anticorrosive paint formulations, where their presence in these formulations is between 50 and 75 per cent of the total pigments in the paint formula. A model of the mechanism of protection to the metal substrate is presented.

Findings

The results show that the presence of these hybrid pigments imparts excellent corrosion protection to steel substrates, in spite of their different concentrations and loadings in the paint films.

Practical implications

These pigments can be applied in other polymer composites, e.g. rubber and plastics as filler and reinforcing agent.

Originality/value

Prepared pigments are eco‐friendly and can replace other hazardous pigments (e.g. chromates) – also it can replace original ferrite pigments. These pigments can compensate for the presence of other known pigments in markets successfully. The main advantage of these pigments is that they combine both the properties of their counter‐parts, and they are of lower cost than the original inhibitive pigment (ferrite). Also, they can be applied in other industries other than paints, e.g. paper, rubber and plastics composites.

Details

Pigment & Resin Technology, vol. 39 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

1 – 10 of 132