Walid S. Abdel-Wakil, Tarek M. Salama, Elbadawy A. Kamoun, Farag Abd El Hai Ahmed, Wassem Hassan, Yaser A. El-Badry and Alaa Fahmy
This paper aims to synthesize new terpolymers by the emulsion polymerization technique composed of acrylamide-based polyurethane monomers (TPM and MPM) with different vinyl…
Abstract
Purpose
This paper aims to synthesize new terpolymers by the emulsion polymerization technique composed of acrylamide-based polyurethane monomers (TPM and MPM) with different vinyl acetate copolymer systems, such as vinyl acetate/butyl acrylate (VAc/BA), vinyl acetate/ethylhexyl acrylate (VAc/2-EHA) and vinyl acetate/vinyl ester of versatic acid (VAc/VEOVA 10) systems. The performance of the prepared terpolymers as binders in emulsion coatings and textile industries was investigated and compared with the analogous commercial ones.
Design/methodology/approach
New waterborne polyurethane-vinyl ester-vinyl acetate terpolymers with high solid content and nano-scale emulsions have been successfully synthesized in two steps. The polyurethane oligomers were prepared by the prepolymer method as the first step. The second step involved polymerization with different vinyl monomers. The synthesized terpolymers were characterized using FTIR, scanning electron microscope, thermogravimetric analysis, minimum film forming temperature and particle size analyzer methods.
Findings
The synthesized emulsion terpolymers have shown small particle sizes averaged of 70 nm and a narrow distribution range, along with good mechanical, thermal and chemical stabilities. The surface coating layers of the terpolymers also have some important in terms of smoothness, clarity and binding ability in water-based coating for up to 4425 scrub cycles at 30 GU. Further, a high potential application textile printing was achieved at high solid content of 47–50%.
Originality/value
The effects of different isocyanates and vinyl monomers on the properties of obtained emulsion coatings have been studied. The improvement consequences of the coating evaluation of the waterborne binders for emulsion paints have been described. The properties of polyester/cotton fabric print pigment printing of textiles appear to be most promising enhancements by using the prepared nanocomposites of PU-co-vinyl acetate-co-vinyl ester as waterborne binders. So that the prepared emulsions have the potential to replace solvent-based coatings as waterborne binders for both emulsion coating and textile printing applications.
Details
Keywords
Wassim Ben Ayed and Rim Ben Hassen
This research aims to evaluate the accuracy of several Value-at-Risk (VaR) approaches for determining the Minimum Capital Requirement (MCR) for Islamic stock markets during the…
Abstract
Purpose
This research aims to evaluate the accuracy of several Value-at-Risk (VaR) approaches for determining the Minimum Capital Requirement (MCR) for Islamic stock markets during the pandemic health crisis.
Design/methodology/approach
This research evaluates the performance of numerous VaR models for computing the MCR for market risk in compliance with the Basel II and Basel II.5 guidelines for ten Islamic indices. Five models were applied—namely the RiskMetrics, Generalized Autoregressive Conditional Heteroskedasticity, denoted (GARCH), fractional integrated GARCH, denoted (FIGARCH), and SPLINE-GARCH approaches—under three innovations (normal (N), Student (St) and skewed-Student (Sk-t) and the extreme value theory (EVT).
Findings
The main findings of this empirical study reveal that (1) extreme value theory performs better for most indices during the market crisis and (2) VaR models under a normal distribution provide quite poor performance than models with fat-tailed innovations in terms of risk estimation.
Research limitations/implications
Since the world is now undergoing the third wave of the COVID-19 pandemic, this study will not be able to assess performance of VaR models during the fourth wave of COVID-19.
Practical implications
The results suggest that the Islamic Financial Services Board (IFSB) should enhance market discipline mechanisms, while central banks and national authorities should harmonize their regulatory frameworks in line with Basel/IFSB reform agenda.
Originality/value
Previous studies focused on evaluating market risk models using non-Islamic indexes. However, this research uses the Islamic indexes to analyze the VaR forecasting models. Besides, they tested the accuracy of VaR models based on traditional GARCH models, whereas the authors introduce the Spline GARCH developed by Engle and Rangel (2008). Finally, most studies have focus on the period of 2007–2008 financial crisis, while the authors investigate the issue of market risk quantification for several Islamic market equity during the sanitary crisis of COVID-19.
Details
Keywords
Mohd Arwab, Mohd Adil, Mohd Nasir and Mohd Ashraf Ali
The purpose of this study is to analyse the perception of employees towards training and also examine the mediation effect of employee engagement between training and task…
Abstract
Purpose
The purpose of this study is to analyse the perception of employees towards training and also examine the mediation effect of employee engagement between training and task performance.
Design/methodology/approach
An integrated model has been developed highlighting the relationship of the motivation for training and support for training and their implications on task performance through the mediating role of employee engagement. Using the sample of 397, structural equation modelling has been used with the help of SPSS and AMOS to validate the hypothesized relationship and evaluate the responses of employees working in travel agencies operating in Delhi (capital), India.
Findings
The findings of this study demonstrated a positively significant relationship between training and task performance of employees in the tourism and hospitality industry. Simultaneously, employee engagement positively mediates the relationship between training and task performance directly and indirectly. This study goes over the ramifications of the findings and offers some suggestions for practical implementations.
Practical implications
The findings of this study can be used by managers and HR professionals to organize exclusive training programs for improving employees’ performance based on the dimensions used in this study. This study also suggests that training program enhances employee engagement in organizational activities which leads to build up team work and overall organizational as well as individual performance.
Originality/value
This study also introduces a conceptual model and theoretical framework that provide a significant contribution to the training and task performance of employees. This study provides a strong theoretical foundation by incorporating the social exchange theory to confirm the role of employee engagement in performance. Further, this novel piece of research explores the relationship between training and task performance with employee engagement as a mediator, especially in the Indian tourism and hospitality industry.