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