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Article
Publication date: 13 November 2007

H. Satapathy and A.K. Banthia

To synthesise and characterise homo and copolymer of 4‐nonylphenyl methacrylate (NPMA) and styrene and to determine monomer reactivity ratios by the application of conventional…

628

Abstract

Purpose

To synthesise and characterise homo and copolymer of 4‐nonylphenyl methacrylate (NPMA) and styrene and to determine monomer reactivity ratios by the application of conventional linearisation methods such as Finemann‐Ross (F‐R) and Kelen‐Tudos (K‐T) methods.

Design/methodology/approach

New methacrylic monomer, NPMA with a pendant nonylphenyl group was copolymerised with styrene. All monomer and polymers (homo and copolymer) are characterised and subsequently the monomer reactivity ratio was determined.

Findings

The monomer reactivity ratios were determined by application of conventional linearisation methods such as F‐R (r1=0.41±0.05; r2=3.47±0.31), K‐T (r1=0.43±0.19; r2=3.54±0.09) methods. The thermogravimetric analysis (TGA) of the polymer in nitrogen reveals that it posses very good thermal stability in comparison to alkyl acrylates due to presence of pendant nonylphnyl group.

Research limitations/implications

New methacrylic monomer, NPMA was synthesised by reacting nonylphenol dissolved in methyl ethyl ketone (MEK) with methacryloyl chloride in the presence of triethylamine as a base. Copolymers of NPMA with styrene were synthesised in MEK using benzoyl peroxide (BPO) as initiator under nitrogen atmosphere at different feed composition.

Practical implications

The method developed is a simple and easy method of copolymerisation of styrene with methacrylate to obtain copolymer of better properties.

Originality/value

The method developed is a novel method for enhancing the thermal, as well as surface adhesion, properties which has several applications in surface coatings and adhesives.

Details

Pigment & Resin Technology, vol. 36 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 11 January 2008

H. Satapathy and A.K. Banthia

The purpose of this paper is to synthesise, characterise and study polymerisation kinetics of novel 4‐nonylphenylmethacrylate (NPMA) polymer.

403

Abstract

Purpose

The purpose of this paper is to synthesise, characterise and study polymerisation kinetics of novel 4‐nonylphenylmethacrylate (NPMA) polymer.

Design/methodology/approach

New methacrylic monomer, 4‐NPMA with a pendant nonylphenyl group was synthesised and characterised using various characterisation techniques. The free radical polymerisation kinetics study was done with the help of differential scanning calorimetry data.

Findings

The average heat of polymerisation (ΔHp) was found to be 685.43 J/g. Activation energy (Ea) of 95.86 kJ mol−1 and frequency factor of (A) 3.4 × 104 min−1 was obtained using Kissinger method. The thermogravimetric analysis of the polymer in nitrogen reveals that it possesses very good thermal stability in comparison to alkyl methacrylates due to presence of pendant nonylphenyl group.

Research limitations/implications

New methacrylic monomer, 4‐NPMA was synthesised by reacting nonylphenol dissolved in methyl ethyl ketone (MEK) with methacryloyl chloride in the presence of triethylamine as a base. Polymerisation of 4‐NPMA was carried out in MEK using benzoyl peroxide (BPO) as initiator under nitrogen atmosphere. The kinetics study of NPMA monomer with 1.1 wt% BPO was reported for evaluation of kinetic parameters by employing the Kissinger equation.

Practical implications

This is a simple and easy method of modification of methacrylate ester with phenyl groups to obtain a polymer of enhanced properties.

Originality/value

This is a novel method for enhancing the thermal as well as surface adhesion properties of methacrylate polymers which finds several applications in surface coatings and adhesives.

Details

Pigment & Resin Technology, vol. 37 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 May 2001

A.K. Satapathy and R.K. Sahoo

A numerical study has been made to investigate the effect of internal heating and precursory cooling during quenching of an infinite tube. The finite difference solution gives the…

407

Abstract

A numerical study has been made to investigate the effect of internal heating and precursory cooling during quenching of an infinite tube. The finite difference solution gives the quench front temperature as a function of various model parameters such as Peclet number, Biot number and dimensionless heat flux. The parametric dependence of the rewetting rate is obtained by the condition that the surface can only be wetted when its temperature is below the quench front temperature. Also, the critical heat flux is obtained by setting Peclet number equal to zero, which gives the minimum heat flux required to prevent the hot surface being rewetted. The numerical model is validated by comparing the results with known closed form solutions.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 11 no. 3
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 9 March 2012

Aruna Panda

The purpose of this paper is to analyze the status of gross and net working capital and their association with sales of Andhra Pradesh Paper Mills Ltd, with reference to the…

3035

Abstract

Purpose

The purpose of this paper is to analyze the status of gross and net working capital and their association with sales of Andhra Pradesh Paper Mills Ltd, with reference to the Indian paper industry over a decade, from 1999 to 2008.

Design/methodology/approach

The research is mainly based on secondary financial data obtained from the Centre for Monitoring Indian Economy (CMIE). It focused on the size, character, and annual growth rates of gross and net working capital of the company. In addition, it analyzed the growth trends of gross and net working capital of the company in relation to sales. With the help of the Karl Pearson's correlation model, the inter‐relationship between sales and working capital has been identified. Then the strength and significance of such a relationship has been tested with the use of other statistical tools such as coefficient of determination and Student's t‐test.

Findings

The major findings of the research showed that while there was an increase in sales positively, strongly, and significantly associated with an increase in gross working capital for both the company and the industry, its association with net working capital was negative, poorly related, weak, and insignificant for the company under study.

Originality/value

There is a dearth of studies in the world literature that discuss the relationship that exists between sales and working capital in India's paper industry, in general and Andhra Pradesh Paper Mills Ltd in particular, and therefore this research is expected to add significant value to exploring the said linkage.

Details

International Journal of Commerce and Management, vol. 22 no. 1
Type: Research Article
ISSN: 1056-9219

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Article
Publication date: 15 July 2019

R.R. Kumar, P.K. Karsh, Vaishali, K.M. Pandey and S. Dey

The purpose of this paper is to investigate the first three stochastic natural frequencies of skewed sandwich plates, considering uncertain system parameters. To conduct the…

210

Abstract

Purpose

The purpose of this paper is to investigate the first three stochastic natural frequencies of skewed sandwich plates, considering uncertain system parameters. To conduct the sensitivity analysis for checking the criticality of input parameters.

Design/methodology/approach

The theoretical formulation is developed based on higher-order-zigzag theory in accordance with the radial basis function (RBF) and stochastic finite element (FE) model. A cubic function is considered for in-plane displacement over thickness while a quadratic function is considered for transverse displacement within the core and remains constant in the facesheet. RBF is used as a surrogate model to achieve computational efficiency and accuracy. In the present study, the individual and combined effect of ply-orientation angle, skew angle, number of lamina, core thickness and material properties are considered for natural frequency analysis of sandwich plates.

Findings

Results presented in this paper illustrates that the skewness in the sandwich plate significantly affects the global dynamic behaviour of the structure. RBF surrogate model coupled with stochastic FE approach significantly reduced the computational time (more than 1/18 times) compared to direct Monte Carlo simulation approach.

Originality/value

The stochastic results for dynamic stability of sandwich plates show that the inevitable source uncertainties present in the input parameters result in significant variation from the deterministic value demonstrates the need for inclusive design paradigm considering stochastic effects. The present paper comprehensively establishes a generalized new RBF-based FE approach for efficient stochastic analysis, which can be applicable to other complex structures too.

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Article
Publication date: 2 September 2019

Aziz Boutouil, My Rachid Laamari, Ilham Elazhary, Hafid Anane, Abdeslem Ben Tama and Salah-Eddine Stiriba

This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely…

113

Abstract

Purpose

This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely, 1-((1-((2,2,7,7-tetramethyltetrahydro-5H-bis([1,3]dioxolo)[4,5-b:4′,5′-d]pyran-5-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazole (TTB) on the corrosion of mild steel in aerated 1 M H2SO4.

Design/methodology/approach

The authors have used weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy, FT-IR studies, scanning electron microscopy analysis and energy dispersive X-ray (EDX) spectroscopy techniques.

Findings

It is found that, in the working range of 298-328 K, the inhibition efficiency of TTB increases with increasing concentration to attain the highest value (92 per cent) at 2.5 × 10−3 M. Both chemisorption and physisorption of TTB take place on the mild steel, resulting in the formation of an inhibiting film. Computational methods point to the imidazole and phenyl ring as the main structural parts responsible of adsorption by electron-donating to the steel surface, while the triazol ring is responsible for the electron accepting. Such strong donating–accepting interactions lead to higher inhibition efficiency of TTB in the aqueous working system.

Originality/value

This work is original with the aim of finding new acid corrosion inhibitors.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 29 April 2014

Innocent Okechi Arukalam, Innocent Chimezie Madufor, Okoro Ogbobe and Emeka E. Oguzie

– The paper aims to investigate the effectiveness of hydroxypropyl methylcellulose (HPMC) as corrosion inhibitor for aluminium in 0.5 M H2SO4 solution.

285

Abstract

Purpose

The paper aims to investigate the effectiveness of hydroxypropyl methylcellulose (HPMC) as corrosion inhibitor for aluminium in 0.5 M H2SO4 solution.

Design/methodology/approach

This study was carried out using weight loss and electrochemical techniques. Inhibition efficiency was determined by comparing the corrosion rates in the absence and presence of inhibitor system. Quantum chemical computations were performed using density functional theory to assess the parameters responsible for the inhibition process and also to analyse the local reactivity of the molecule.

Findings

HPMC inhibited aluminium corrosion in the acidic environment. The inhibition efficiency was found to depend on concentration of the inhibitor. Impedance results reveal that HPMC is adsorbed on the corroding metal surface. Polarization results show that the dissolution reaction is due to destabilization of the passive oxide film on the Al surface. Adsorption of the inhibitor is approximated by Freundlich adsorption isotherm and the calculated standard free energy of adsorption indicates weak physical interaction between the inhibitor molecules and aluminium surface. This can be attributed to preferential interaction of the active sites with the passive oxide layer. The calculated quantum chemical parameters show good correlation with the inhibition efficiency.

Practical implications

HPMC could find possible application as a polymeric thickener and additive to improve corrosion resistance and barrier properties of anticorrosion paints.

Originality/value

This paper provides novel information on the inhibitive characteristics of HPMC under the stated conditions. The inhibitor systems provide an effective means for suppressing aluminium corrosion even in highly aggressive acidic environments.

Details

Pigment & Resin Technology, vol. 43 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 5 January 2015

A.E. Okoronkwo, S.J. Olusegun and O.O. Oluwasina

The purpose of this investigation was to study the inhibitive action and adsorption potential of chitosan extracted from Archachatina marginata snail shells on the corrosion of…

216

Abstract

Purpose

The purpose of this investigation was to study the inhibitive action and adsorption potential of chitosan extracted from Archachatina marginata snail shells on the corrosion of plain carbon (mild) steel in acid media.

Design/methodology/approach

Weight loss and thermometric methods were used during this investigation. Characterization of the obtained chitosan was accomplished with Fourier transform infrared spectroscopy analysis. The effects of parameters influencing the inhibition process (concentration and temperature) were evaluated, and the sorption isotherms and thermodynamic parameters were derived.

Findings

The results obtained showed that chitosan has good inhibition potential with an efficiency of 93.2 per cent. The inhibition efficiency decreased with an increase in temperature but increased with increasing concentration of chitosan. Test results best fitted the Langmuir Isotherm with a correlation coefficient (R2) of 0.999. The thermodynamic parameters studied reveal that the adsorption of chitosan on the surface of mild steel is spontaneous.

Originality/value

The paper fulfills an identified need in finding solutions to the problems of metal corrosion using agricultural wastes.

Details

Anti-Corrosion Methods and Materials, vol. 62 no. 1
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 June 2015

M Saadawy

The purpose of this paper was to test the extract of barley as an environmentally friendly inhibitor for the acid corrosion of steel due to its wide availability as a popular…

251

Abstract

Purpose

The purpose of this paper was to test the extract of barley as an environmentally friendly inhibitor for the acid corrosion of steel due to its wide availability as a popular major crop and its richness with different chemical constituents reported in literature (40) like alanine, glycine, serine, aspartic acid, leucine, valine, tyrosine and isoleucine with various number of functional groups that are able to chelate metal cations and to discuss the effect of temperature on its inhibition efficiency.

Design/methodology/approach

Electrochemical impedance spectroscopy (EIS) and polarization measurements were carried out using frequency response analyzer Gill AC instrument. The frequency range for EIS measurements was 0.1 ≤ f ≤ 1 × 103 with an applied potential signal amplitude of 10 mV around the rest potential. Polarization measurements were carried out at a scan rate of 30 mV/min, utilizing a three-electrode cell. A platinum sheet and saturated calomel electrode were used as counter and reference electrodes, respectively. The working electrode was constructed with steel specimens that have the following composition (weight per cent): C, 0.21; S, 0.04; Mn, 2.5; P, 0.04; Si, 0.35; and balance Fe.

Findings

Barley extract could act as an effective corrosion inhibitor for the acid corrosion of steel. The inhibiting action of the barley extract was attributed to its adsorption over the metal surface that blocks the available cathodic and anodic sites. Adsorption isotherms indicated that the adsorbed extract molecules cover one active center over the metal surface.

Originality/value

The research included the first use of an important world crop as an effective corrosion inhibitor that can reduce the corrosion of steel to an extent of 94 per cent.

Details

Anti-Corrosion Methods and Materials, vol. 62 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 8 February 2016

Mehmet Bagci and Huseyin Imrek

This study aims to examine solid particle erosion behavior of novel hybrid composite materials where borax (B2O3) particles (∼150 μm) were added to glass fabric and epoxy resin at…

221

Abstract

Purpose

This study aims to examine solid particle erosion behavior of novel hybrid composite materials where borax (B2O3) particles (∼150 μm) were added to glass fabric and epoxy resin at an amount of 15 and 30 per cent.

Design/methodology/approach

The tests that involved slightly rounded and irregular Al2O3 particles having two erodent sizes (200, 400 μm) were conducted at these operational conditions; namely, three impact velocities (23, 34, 53 m/s), two fabric directions (0/90/0, 45/−45/45) and three impingement angles (30°, 60°, 90°). In addition, the design of experiments, which utilizes Taguchi’s robust orthogonal arrays approach, was used and an optimum parameter combination was established, which had a minimum erosion rate. Moreover, scanning electron microscope and X-ray diffraction views show the visual effect of filler material.

Findings

All test specimens regardless of their dissimilar characteristics displayed maximum erosion rate at 30° impingement angle. Test specimens with 45/−45/45 fabric direction are more wear-resistant than their counterparts with 0/90/0 fabric direction. The erosion wear of glass fabric reinforced epoxy (GF/EP) composites whose matrix had 15 per cent addition of borax particles was higher than that of neat GF/EP composites. In addition, new composite material formed by including borax particles at a rate of 30 per cent of resin leads to a reduction in erosion rates.

Originality/value

While fabric-reinforced polymers take place in most of the studies conducted on erosive wear of composites, studies involving erosion on composites with filler materials can hardly be encountered.

Details

Industrial Lubrication and Tribology, vol. 68 no. 1
Type: Research Article
ISSN: 0036-8792

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