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To synthesize some new heterocyclic disperse azo dyes and their utilization in textile printing.

To prepare 1‐cayno‐1‐substituted aryl azo‐2‐methyl benzothiazole by the reaction of 2‐aminothiophenol with malononitrile and the end product coupled with different diazonium salts. The prepared dyestuffs are established using element analysis, IR measurements, ¹H‐NMR and Mass spectra. Printing pastes containing the prepared dyestuffs and a thickener were used for printing polyester and/or nylon 6 using either transfer printing or traditional printing.

New selected arylazo cyanomethyl benzothiazole dyes were obtained from the reaction of diazotized aniline derivatives with 2‐cyanomethyl benzothiazole as a coupling component. The suitability of the prepared dyestuffs for either heat transfer printing or traditional printing on polyester and nylon 6 fabrics has been investigated. The prints obtained from dyes containing non polar groups which have sublimation properties possess high colour strength as well as good overall fastness properties if compared to those obtained using dyes containing polar groups.

The new heterocyclic disperse azo dyes were prepared from 2‐cyanomethylbenzothiazole and were utilized in preparing pastes for textile printing to print polyester and nylon 6 fabrics. In addition, the variation in substituents on the synthesized dyes could also be studied.

The method of synthesis of the new dyestuffs provides a simple and practical solution to prepare some new heterocyclic disperse azo dyes with low molecular weight, suitable for sublimation in heat transfer printing methods.

The methods for synthesis of the new heterocyclic disperse azo dyes are simple. These dyestuffs could be used in textile printing of polyester and nylon 6 on an industrial scale.

Cellulosic wastes from El-Nasr Co. for Intermediate Chemicals are used as a starting material for the preparation of methylcellulose with tailored properties. The wastes are first purified, followed by alkali ageing for different intervals of time. This is done to control the molecular weight of the cellulose molecules, thereby obtaining cellulosics with different degrees of polymerization (DP). These samples along with the original purified cellulose are methylated under similar conditions and the obtained methylcellulose samples are examined for solubility, degree of substitution (DS) and rheological properties. The results obtained from these investigations are summarized as follows. It is found that the DP of the starting cellulose progressively decreases by prolonging the duration of alkali ageing, while the carboxyl content increases. The DS of the methyl groups increases as the DP of the starting substrate decreases. The rheological properties as well as the apparent viscosity at various rates of shear for the prepared derivatives are thoroughly investigated.

This paper aims to study the physical and chemical characteristics of inkjet titanium dioxide inks for cotton fabric digital printing.

Different dispersing agents through the reaction of glycerol monooleate and toluene diisocyanate were prepared and then performed by using three different polyols (succinic anhydride-modified polyethylene glycol PEG 600, EO/PO Polyether Monoamine and p-chloro aniline Polyether Monoamine), to obtain three different dispersing agents for water-based titanium dioxide inkjet inks. The prepared dispersants were characterized using FTIR to monitor the reaction progress. Then the prepared dispersants were formulated in titanium dioxide inkjet inks formulation and characterized by particle size, dynamic surface tension, transmission electron microscopy, viscosity and zeta potential against commercial dispersants. Also, the study was extended to evaluate the printed polyester by using the prepared inks according to washing and crock fastness.

The obtained results showed that p-chloro aniline Polyether Monoamine (J) and succinic anhydride modified polyethylene glycol PEG 600 (H) dispersants provided optimum performance as compared to commercial standards especially, particle size distribution data while EO/PO Polyether Monoamine based on dispersant was against and then failed with the wettability and dispersion stability tests.

These ink formulations could be used for printing on cotton fabric by DTG technique of printing and can be used for other types of fabrics.

The newly prepared ink formulation for digital textile printing based on synthesized polyurethane prepolymers has the potential to be promising in this type of printing inks, to prevent clogging of nozzles on the printhead and to improve the print quality on the textile fiber.

This paper aims to synthesize new screen-printing ink formula based on new derivatives of azo thiadiazol disperse dyes and evaluate their characteristics after being printed on polyester fabric substrates.

New dispersed dyes based on 1, 3, 4-Thiadiazole derivatives (dyes 1 and 2) were prepared and confirmed by different analyses, infrared (IR), mass and nuclear magnetic resonance (NMR) spectroscopy, and then formulated as colored materials in the screen-printing ink formulations. Printing pastes containing the prepared dyestuffs and other ingredients were used for printing polyester using screen-printing or traditional printing. The characteristics of printed polyester fabric substrates were measured by color measurements such as a*, b*, L*, C*, E, Ho, R% and color strength, as well as light, washing, crock and alkali perspiration fastness, and finally, the depth of penetration was evaluated.

The prepared 1, 3, 4-Thiadiazole derivatives (dyes 1 and 2) were obtained from the reaction of 5,5’-(1,4-phenylene)bis(1,3,4-Thiadiazole-2-amine) with resorcinol and m-toluidine as a coupling component. The suitability of the prepared dyestuffs for silk screen-printing on polyester fabrics has been investigated. The prints obtained from a formulation containing dye 1 possess high color strength as well as good overall fastness properties if compared to those obtained using dye 2.

The method of synthesis of the new dyestuffs and screen-printing ink provides a simple and practical solution to prepare some new heterocyclic disperse azo dyes, and they are formulated in the screen-printing inks for printing on a polyester fabric substrate.

The prepared disperse dyes based on 1,3,4-Thiadiazole derivatives (dyes 1 and 2) could be used in textile printing of polyester on an industrial scale.

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.

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.

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.

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.

This study aims to use hexanediol, pentaerythritol and keratin as crosslinking agents on the acrylic fabric used as garments.

Plain 1/1 acrylic fabric was produced with 14 and 11 weft yarn/cm using yarn count 28/2 Ne, then it was modified with different agents, and the effect of crosslinking on some of the inherent properties was determined. The color strength as well as washing fastness was evaluated. The Fourier transform infrared spectroscopy determined the changes that acted in the structure of the treated acrylic fabrics. Several physical and functional utility characteristics were studied such as stiffness, crease recovery, tensile strength and elongation, pilling, air permeability, absorbency and static electricity.

Polyacrylonitrile is one of the man-made materials used in the textile field; despite novel characteristics, it has some negative properties, especially in absorbency and pilling, which are improved after treatment.

The results presented that the different conditions that were used with cross-linkers enhanced the acrylic fabrics properties. Where analysis of variance test at P-value 0.05 and radar chart area offered that the treated acrylic fabric with 5% (w/v) keratin accomplished the highest preferable properties for end use.

A disperse fluorescent yellow paste was mixed with a dispersant naphthalene sulfonic derivative via wet grinding process to prepare thermal transfer ink with good fluorescence. The paper aims to discuss these issues.

The surface tension, viscosity, pH value, zeta potential, stability and the morphology of ink samples were tested after the storing process.

The morphology of paste was homogeneous nearly spherical nanoparticles and the particle size was about 100 nm from the transmission electron microscopy (TEM), which was similar to the average particle size obtained from the particle size analyser.

The paste particle size was 126.8 nm after storing at 50°C for one week. The addition of diethylene glycol was conducive to high fluorescent reflectivity and gave good line image quality both in warp and weft directions due to the low viscosity. Inkjet printed polyester fabrics achieved excellent rubbing, laundering and thermal subliming fastnesses.

The polyester fabrics thermal transferred with the ink contained diethylene glycol represented higher fluorescent reflectivity and gave better line image quality both in warp and weft directions. The inkjet printed polyester fabrics showed excellent colour reproducibility and all the fastnesses, including rubbing, laundering and thermal subliming, were higher than Grade 4.

This research aims to examine the impact of virtual learning platforms and instructor presence (IP) on learner satisfaction (LS). Further, this study examines the role of learner engagement (LE) in order to improve the LS.

This research uses both primary and secondary data sources to compile the research's findings. The primary source of data includes 610 responses from various higher education institutes in India. The collected data were analysed using the partial least square structural equation modelling (PLS-SEM) technique.

This research provides evidence that the theoretical model is accurate with the gathered data sample. In the model, online platform (OP) is an independent variable, whereas LS is a dependent variable, and IP and LE are the mediating variables. The outcomes demonstrated that OP has a positive impact on IP and LE. Also, the relationships between IP and LE, IP and LS and LE and LS are significantly positive. The mediation analysis validates the importance of the IP and LE for relationships.

This investigation presents a comprehensive model, which demonstrates the relationship between OP, IP, LE and LS. The study makes a unique reference to several theories in order to boost interaction and IP in virtual learning, the learner's learning experience can be enhanced. The model helps teachers and educational institutions formalise strategies to boost interaction and examine the institutions' pedagogy to enhance satisfaction.

This study aims to investigate the conditional indirect effect of academic self-efficacy in the interplay between academic motivation and academic satisfaction through academic engagement among university students.

A cross-sectional study was performed on 1,638 Vietnamese university students (31.9% males and 68.1% females) aged 16 to 36 (Mean = 20.06, SD = 1.428). The participants filled out a questionnaire with the Vietnam versions of the General Self-Efficacy Scale, Academic Motivation Scale, Academic Life Satisfaction Scale and Academic Engagement Scale. Model 4 and Model 7 in the PROCESS macro were used for the mediation analysis and the moderated mediation analysis.

Results showed that the indirect effect of academic engagement on the academic motivation-academic satisfaction link was significant. Furthermore, academic self-efficacy moderated this indirect effect. The indirect effect was stronger among students with high academic self-efficacy and weaker among students with low academic self-efficacy.

This study’s findings contribute to educational research on academic satisfaction and can be used by institutions of higher education and educators to enhance academic satisfaction among university students.

Given the disruption of the COIVD-19 pandemic in higher education, this study seeks to understand possible changes in students’ ratings and textual reviews of higher education institutions posted on Niche College Rankings (niche.com) prior to and after the COVID-19 pandemic.

This study utilized a text analytics technique to identify the positive and negative keywords of students’ sentiments expressed in their textual reviews provided on niche.com. After identifying the positive and negative sentimental keywords, this study performed ordinal logistic regressions and analyzed the statistical effects of these positive and negative sentimental keywords on the types of student ratings of a higher education institution.

Results from 15,666 online reviews provided by students on niche.com indicate the following. First, eight positive sentimental keywords such as “outstanding” and “love” have a significant impact on students’ positive ratings of a higher education institution prior to COVID-19, whereas eight positive sentimental keywords such as “amazing” and helpful” have a significant impact on students’ positive ratings of a higher education institution after COVID-19. Second, twenty-eight negative sentimental keywords such as “difficult” and “frustrating” have a significant impact on students’ negative ratings of a higher education institution prior to COVID-19, whereas thirty negative sentimental keywords such as “complex” and “hate” have a significant impact on student negative ratings of a higher education institution after COVID-19.

This study is one of the first few studies investigating higher education institution ratings and reviews provided by students. Additionally, this study provides an understanding of student positive and negative sentiments expressed in textual reviews posted prior to and after the COVID-19 pandemic. By doing so, this study provides a basis for future research seeking to understand student textual reviews of higher education institutions. Additionally, this study offers higher education administrators some recommendations that may foster student positive campus experience while minimizing negative sentiments.