Synthesis of benzothiazole-azo disperse dyes for high resistance to alkaline treatments and peroxide bleaching

Purpose This paper aims to synthesize benzothiazole-azo disperse dyes which can be applied not only for dyeing and alkaline reduction of polyester fabric in one bath, but also for dyeing and peroxide bleaching of cotton/polyester blend fabric in one bath. Design/methodology/approach The synthesized benzothiazole-azo disperse dyes were confirmed by proton nuclear magnetic resonance (1H-NMR) spectroscopy, mass spectroscopy (MS) and UV–visible spectrophotometry. The performance on resistance to alkaline treatment and peroxide bleaching was tested by measuring the color strength of polyester fabric dyed with the synthesized benzothiazole-azo disperse dyes under high-temperature and high-pressure conditions. Findings Increasing the electron-withdrawing ability of the substituents in the diazo component and the electron-donating ability of the substituents in the coupling component resulted in a significant bathochromic shift of the maximum absorption wavelength. Except that the disperse dyes synthesized from the coupling components containing the hydroxyethyl group were unstable in alkaline solution, all others exhibited high resistance to alkaline treatment and peroxide bleaching. Practical implications The synthesized benzothiazole-azo disperse dyes provide the opportunities to combine dyeing and alkaline reduction of polyester fabric into one bath, and combine dyeing and peroxide bleaching of cotton/polyester blend fabric into one bath. Originality/value The synthesized benzothiazole-azo disperse dyes help to establish short processes of polyester and polyester/cotton blend fabrics so as to reduce energy consumption and raise production efficiency.

Production of Electroconductive, Superhydrphobic and Flame-Retardant Cotton Fibers via Pad-Dry-Cure Process using Silicone Rubber and Ammonium Polyphosphate

Although pyrovatex has been widely utilized as commercial flame-retardant material, the discharge of poisonous formaldehyde is still a major concern. On the other side, fluorine-based materials have been successfully used to impart superhydrophobic textile surfaces, but they are highly expensive and extremely toxic. Based on these challenging concerns, we report a simple one-step method for the production of flame-retardant and water-repellent coating onto an electroconductive cotton-nickel (Cot-Ni) blend fabric. Firstly, the electroconductive cotton was prepared by weaving nickel strip twisted around cotton core yarns, which were then weaved with pure cotton yarns to introduce Cot-Ni blend fabric. Secondly a composite comprising ammonium polyphosphate (APP) and room-temperature vulcanized silicone rubber (RTV) was applied onto the electroconductive cotton fabrics via one-step pad-dry-cure technique. Results showed that the flame-retardant effect of cotton was enhanced due to the high binding of RTV with both APP and cotton fibers. Thus, different concentrations of APP were implemented in the composite to establish that only 100 g/L of APP with RTV presented an improved fire-retardancy. The surface of Cot-Ni fabric displayed different hierarchical morphologies relying on the concentration of APP. Moreover, RTV further enhanced the superhydrphobic nature of cotton surface. Importantly, the superhydrophobic activity was characterized by static water contact angle of the coated Cot-Ni blend. The CIE Lab colorimetric measurements of the coated Cot-Ni blend were also explored. The comfort characteristics of the coated Cot-Ni blend were assessed by measuring their air permeability and stiffness. Ultimately, these multifunctional cotton-nickel (Cot-Ni)/RTV-APP treated fabrics could be suitable for diverse applications, including firefighters’ wear, car seat mats, and grain storage containers.

Choline-Based Deep Eutectic Solvent and Microwave Irradiation as Tools for PET Identification in Blend Fabric

A new, rapid, and eco-friendly technique for identification of polyethylene terephthalate (PET) composition in blend fabric was developed. This technique could replace a conventional composition identification of PET using toxic chemicals such as halogenated organic solvent or strong inorganic acid. Choline-based deep eutectic solvents (DES), such as ethylene glycol- choline chloride, were used as a treatment medium under microwave irradiation. The PET portion of the blend fabrics, such as 65/35 and 50/50 PET/cotton was completely removed by DES containing 5% NaOH (w/v) after 100–140 s of microwave irradiation. Various instrumental analyses confirmed the removal of PET. Finally, a commercial sample was also tested as a practical application of the new test method.

Effect of Organic Alternative Scouring Agents on Structure of Cellulose/Polyester Blend Fabric

This study investigated the effect of organic alternative scouring agents on structure of cotton/polyester blend fabric. A structural modification for a cellulose/polyester blend has been carried out using (COOH)2, CH3COOH and CH3CH2OH alternative scouring agents and NaOH was used as control. The scoured fabrics were then subjected to structural analysis using X-ray diffraction in order to expose the possible modifications on the pretreated fabrics. The samples showed possibilities of being highly competitive with the conventional agent. These inferences were drawn from the difference in the crystallinity index of scoured samples (10.10-60.03%), the crystallite size of scoured samples (6-9 nm) in the crystalline region (6-11 nm), in the amorphous region, inter-planar spacing of the scoured samples (0.340-0.350 nm) of the crystalline region and (0.360-0.390 nm) of the amorphous region of sample and number of crystalline planes of the scoured sample is (3-10) of the cellulose/polyester blend fabric samples via X-ray diffraction studies. Keywords; Cellulose, Fabric, Organic, Polyester, Scouring Agents

EFFECT OF INORGANIC ALTERNATIVE SCOURING AGENTS ON STRUCTURE OF CELLULOSE/POLYESTER BLEND FABRIC

In this research, a structural modification for a cellulose/polyester blend has been carried out using NH4OH, (NH4)2C2O4 and liquid NH3 which are environmentally friendly alternative scouring agents with NaOH as control. The scouring process was carried out on the samples with these alternative agents. Investigation into structural modification of cellulose/polyester blend fabric using NH4OH, (NH4)2C2O4 and liquid NH3 and its structural characterization with X-ray diffraction was carried. The results showed the inferences variation in the crystallinity index of scoured samples from (3.21-65.30%), the crystallite size of scoured samples (1.9-15 nm) in the crystalline region and (7-20 nm) in the amorphous region, inter-planar spacing of the scoured samples (0.340-0.350 nm) of the crystalline region and (0.350-0.340 nm) of the amorphous region and number of crystalline planes of the scoured samples is (3-11) of the cellulose/polyester blend fabric samples via X-ray diffraction studies. Among these alternative agents (NH4)2C2O4 and NH4OH showed better interaction with both amorphous and crystalline regions of the cellulose/polyester blend fabric samples without loss in crystallinity when used as scouring agents, and the possibilities of being a superior alternative with significant effect on the structures of the cellulose/polyester blend, while the other samples showed possibilities of being highly competitive with the conventional agent.

Effects of Ultraviolet Pretreatment on Pigment Printing of Cotton / Polyester Blend Fabric

Introduction: Pigments have become the largest colorant group for textile prints because pigment printing is the oldest and cheapest method. Binders are used to fix pigments to the fibers by adhesion. Pigment binders play a significant role in pigment printing because it encloses the pigment particles and adheres to the fiber. Objective: In this study, cotton/polyester blend fabrics were treated with ultraviolet light (UVB) at an air pressure of 1 atm to improve printability. Methods: To study the influence of pretreatment time, experiments were carried out at different exposure times. Untreated and UV treated fabrics were analysed by Fourier-transform infrared spectroscopy to investigate changes in the chemical composition of fabrics. It was observed that carbonyl groups were formed on the surface of UV pretreated cotton fibers. Scanning Electron Microscopy (SEM) was used to investigate the roughness and cracks on the treated fiber surface. Then, all UV treated and untreated fabrics were screen printed with different kinds of pigments. The color strength of the printed fabrics and fastness properties to washing and dry/wet rubbing were evaluated. Results: Experimental data showed that atmospheric UV pretreatment led to an increase in pigment uptake. Moreover, UV pretreated fabrics had better dry and wet rubbing fastness compared with untreated fabrics. Conclusion: The washing fastness of UV pretreated fabric showed no significant change and was comparable with that of untreated fabric. The loss in tensile strength of UV pretreated fabrics was greater than untreated samples.