N-halamine-bonded cotton fabric with antimicrobial and easy-care properties

N-halamine precursor 2,2,6,6-tetramethyl piperidinol (TMP), a hindered amine light stabilizer, was bonded onto cotton fabric by using 1,2,3,4-butanetetracarboxylic acid (BTCA) as a crosslinking agent. A variety of treating conditions including TMP concentration, curing temperature and time, and catalyst were studied. The treated fabrics were characterized using FTIR spectra and scanning electron microscope (SEM). The cotton fabric treated with TMP precursor could be rendered biocidal upon exposure to dilute household bleach. The chlorinated cotton swatches showed great efficacy and inactivated 100 % of Staphylococcus aureus with 7.1 log reduction with 5 min of contact and 83.25 % of E. coli O157:H7 at 10 min of contact. In addition, the wrinkle recovery angle of the treated cotton fabrics increased from 229 ° of untreated cotton fabrics to 253 °. This study provided a practical finishing process to produce cotton fabrics with easy care and antibacterial functionalities at the same time.     

Non-phosphorus catalysts for the ester cross-linking of cellulose with 1,2,3,4-butanetetracarboxylic acid

We studied eight carboxylates as potential catalysts for the cellulose cross-linking with 1,2,3,4-butanetetracarboxylic acid (BTCA) and compared them with sodium hypophosphite (SHP). The results showed that the fabrics treated with sodium formate (SF) exhibited the highest wrinkle recovery angle (WRA) among the selected carboxylates, nearly equivalent to the WRA of the fabrics treated with SHP. We compared the radii and relative concentration ratios of different carboxylates anions, and found that SF had a particular amount of anions in the optimum pH range of the BTCA finishing bath, and had the smallest anion radius, both of which accounted for the higher WRA. The SF anions were present throughout the curing process. Based on the thermogravimetric analysis curves of SF and SHP, SF significantly decreased the temperature of the anhydride formation. In addition, the FTIR spectra displayed a stronger ester absorbance of the fabrics treated with BTCA/SF than those treated only with BTCA, which confirmed that SF accelerated the esterification between BTCA and cellulose.     

Effect of glycols and catalysts on cotton fabrics treated with glyoxal

The optimum conditions for durable press treatment of cotton fabrics using glyoxal as a nonformaldehyde crosslinking agent were investigated. Crosslinking reaction was conducted in the presence of different catalysts such as aluminum sulfate, magnesium chloride, or magnesium chloride-citric acid mixture at various mole ratios of catalyst to glyoxal. Aluminum sulfate was proven the most effective one among those used. Glycol addition into a glyoxal padding bath increased the wrinkle recovery angle(WRA) and whiteness of treated fabrics. The optimum mole ratio of glycol to glyoxal was 1:1. Diethylene glycol addition produced better overall performance to the glyoxal-crosslinked fabric compared to ethylene glycol addition.     

An Eco-Friendly Multifunctional Nano-Finishing of Cellulose/Wool Blends

A new approach for an eco-friendly multi-functionalization of cotton/wool (C/W) and viscose/wool (V/W) blended fabrics was investigated. In this study, Ag-nanoparticle (Ag-NP) and/or ZnO-nanoparticle (ZnO-NP) functional agents were incorporated into the finishing bath along with citric acid (CA) or succinic acid (SA) as ester-crosslinking or esterifying agent, and sodium hypophosphite catalyst using the padding technique. The obtained results indicated that the extent of multi-functionalization expressed as antibacterial activity, UV-blocking functionality and wrinkle recovery ability were determined by kind of nanomaterial, nature of carboxylic acid, i.e., bi- or tri-functional and type of substrate. The results also demonstrated that blended fabrics finished with Ag-NP/ZnO-NP/CA/SHP nano-finishing formulation exhibited outstanding durable multi-functional properties even after 10 washing cycles. In addition, the change in surface morphology and the existence of Ag and/or Zn onto the selected V/W fabric surfaces have been confirmed by SEM and EDX analysis respectively.     

Performance improvement of nonformaldehyde wrinkle resistant finished cotton fabrics treated with dialdehydes

Additives, such as sodium perborate and borax, were examined in dialdehyde wrinkle resistant finishing of cotton. Results indicated that the whiteness index (WI) of cotton treated with dialdehyde and additive showed about 90% of WI of the untreated cotton but with decrease in wrinkle recovery angle (WRA) due to inhibition effect of these additives. Effect of additive on the WRA reduction was more prominent with glutaraldehyde than with glyoxal. Reduction in WRA of cotton treated with both dialdehydes and boron compound was minimized by simultaneous addition of formic acid in the bath. Addition of formic acid was also generally beneficial in maintaining WI retentions after 8 months storage. Furthermore, boron compounds were also effective in improving retentions of mechanical properties. By FTIR analysis the residual aldehyde group was detected on the dialdehyde-finished cotton, whereas no peak was shown by addition of boron compounds. This suggested that the residual aldehyde group was a main cause of fabric yellowing on the dialdehyde-finished cotton. Dialdehyde with boron compound, therefore, can be used to replace a conventional formaldehyde-containing wrinkle resistant finishing of cotton.     

Durable press finish of cotton fabric using malic acid as a crosslinker

It has been considered that malic acid,α-hydroxy succinic acid, could not form crosslinks in the cellulosic materials unless activated by other polycarboxylic acids such as butanetetracarboxylic acid or citric acid because there are only two carboxylic acids per molecule available for the formation of one anhydride intermediate. However we found that the dicarboxylic malic acid with sodium hypophosphite catalyst without the addition of other crosslinkers was able to improve wrinkle resistance of cotton up to 294° (dry WRA) and 285° (wet WRA), which is a measure of crosslinking level in cotton.¹H FT-NMR, FT-IR and GPC analysis indicated the in-situ formation of an trimericα, β-malic acid with a composition of 1:3 through the esterification between hydroxyl group and one of carboxylic groups in malic acid during curing. The crosslinking of cotton was attributed to the trimericα, β-malic acid, a tetracarboxylic acid, which can form two anhydride rings during curing. The influence of crosslinking conditions such as concentrations of malic acid and catalyst, pH of the formulation bath, and curing temperature were investigated in terms of imparted wrinkle resistance and whiteness. The addition of reactive polyurethane resin in the formulation slightly increased the mechanical strength retention of crosslinked fabric coupled with additional increase in wrinkle resistance.     

The effect of biodegradable organic acids on the improvement of cotton ink-jet printing and antibacterial activity

In this study, various biodegradable organic acids with varying numbers of carboxylic acid groups were incorporated into the ink formulation both in the presence and absence of sodium hypophosphite (SHP) to investigate the colour yield and antibacterial properties. Ink-jet prints on cotton fabric, which were either pretreated (industry standard practice) or non-pretreated, were analyzed to determine if there is a significant difference in their properties. Antibacterial activities and dye fixation of printed cotton fabrics were also tested. The results indicated that at optimum pH, the non-pre-treated samples printed with ink formulations containing more carboxylic acid groups in their structure (BTCA) in the absence of SHP, demonstrated higher levels of reactive dye fixation and antibacterial properties than pre-treated samples containing no biodegradable organic acid in the ink formulation. The printed cotton fabrics with ink formulation that contained BTCA without dye were characterized by ATR-FTIR and thermogravimetric analysis (TGA) and their morphology was investigated through the use of SEM to determine if cross-linking had taken place.     

Synthesis and Characterization of Waterborne Polyurethane Modified by Acrylate/nano-ZnO for Dyeing of Cotton Fabrics

Waterborne polyurethane modified by acrylate/nano-ZnO (PUA/ZnO) was synthesized and used to improve the wet rubbing fastness of reactive dyed cotton fabric. The reaction conditions were optimized and the products were characterized by FT-IR, TG, DSC, SEM, and particle size distribution. The dyed cotton fabrics were finished with PUA/ZnO emulsion and the rubbing fastness, ultraviolet resistant property, and wearability of treated fabrics were measured. The wet rubbing fastness of treated fabrics was increased by about 0.5–1 rate to achieve 3–4 rate, and the ultraviolet protection factor (UPF) achieved 50+ level. The whiteness, air permeability, and elongation at break of treated fabric were not decreased significantly. SEM showed that the smooth and reticular coating on the surface of treated fabric reduced the mechanical friction force between dyed fabric and rubbing cloth, and thus improved the rubbing fastness. The decomposition temperature of finished fabric was increased by 50–80 °C.     

Cotton Dyeing and Antibacterial Finishing Using Agricultural Waste by an Eco-friendly Process Optimized by Response Surface Methodology

In this study, Berberis vulgaris L. wood as an agricultural waste was used for dyeing and functional finishing of cotton. To facilitate the attachment of natural dye, citric acid was used to create carboxylic acid functional groups on cotton fibers. The process of crosslinking of cotton fabric with citric acid was optimized in order to obtain the maximum dyeability with the cationic natural dye. The effects of three important factors including citric acid concentration, sodium hypophosphite concentration and curing temperature on the color strength of the dyed samples with woods of barberry tree were analyzed by response surface methodology and the optimum conditions for obtaining the highest color strength was obtained. The crosslinking of citric acid on cotton fibers was confirmed by FTIR spectroscopy. The dyed sample prepared under the optimum conditions of crosslinking showed good wash and light fastness properties besides very good antibacterial activity against gram-negative and gram-positive bacteria.     

Properties of anti-UV-finished cotton fabrics cured by blue light irradiation

To decrease the pollution discharge and energy consumption resulting from textile finishing using the conventional pad-dry-cure process, a blue light-curable digital finishing for textile was innovatively proposed. Based on the mechanism of blue light curing technique, a combination of the blue light curing process and anti-UV finishing was established in this study. A blue light-curable anti-UV finishing solution containing oligomers, monomers, photoinitiators, and anti-UV agents was padded onto the surface of the cotton fabrics, and then cured to form a tough film under blue light irradiation. The ultraviolet protection factor (UPF) value of the finished cotton fabrics was 50, the top level of international standards, demonstrating excellent UV resistance. The finished cotton fabrics also showed good rubbing and washing durability, and acceptable handle. The integration of an anti-UV finishing with the blue light curing technique presents some unique advantages in terms of environmental protection and application potential.     

Modelling tearing behavior of durable press finished woven fabric

Tearing strength is one of the most important and critical properties related to durable press finished cotton woven fabric. In the past, modelling of tearing strength of cotton woven fabrics was based on untreated cotton woven fabric but not in durable pressed finished fabric. In this paper, a mathematical model was established to demonstrate the tearing strength mechanism of durable press finished cotton woven fabrics by dimensional analysis based on yarn diameter, cover factor, Young’s modulus and fabric elongation. The proposed model agreed well with experimental results and the proposed model can be used for optimizing durable press finishing process of cotton woven fabric.     

Effect of concentration of titanium dioxide acting as catalyst or co-catalyst on the wrinkle-resistant finishing of cotton fabric

The wrinkle-resistant property of cotton specimens treated by 1,2,3,4-butanetetracarboxylic acid (BTCA) and catalysed by sodium hypophosphite (SHP) in the presence of TiO₂ or nano-TiO₂ has been evaluated in the present study. In this study, Scanning Electron Microscopy proved the presence of TiO₂ or nano-TiO₂ on the fibre surface. It was also found that 0.1–0.2 % TiO₂ or nano-TiO₂ was the optimum concentration to enhance the wrinkle-resistance of BTCA-SHP-treated cotton fabrics. In addition, the TiO₂ or nano-TiO₂ added in the wrinkle-resistant treatment could act as a multi-functional finishing agent to improve the UV protection property while they are safe to human skin as proved by the cytotoxicity test. Therefore, TiO₂ or nano-TiO₂ was evident that they could enhance the finishing performance and minimise the side effect.     

A new catalyst for glyoxal durable press finish of cotton fabrics

Aluminum ammonium sulfate was used as a new catalyst for glyoxal to minimize the decrease of physical properties of durable press cotton fabrics, and the optimum treatment conditions such as the concentration of glyoxal, molar ratio of catalyst to glyoxal, curing temperature and time were investigated. The retention of tensile strength and the whiteness of fabrics treated with glyoxal/aluminum ammonium sulfate was increased as much as to the degree of that obtained with glyoxal/aluminum sulfate while wrinkle recovery angles were as good as those of the latter. Some additives such as DEG, polyurethane and softener were used to improve the physical properties. When DEG or polyurethane was added to the glyoxal padding solution, wrinkle recovery angle (WRA) significantly increased while tensile strength and whiteness were not influenced. DEG added to the glyoxal padding solution increased the durability of DP finish. The softener added to the glyoxal padding solution increased the WRA of treated fabrics while it decreased the tensile strength slightly. The whiteness of fabrics treated with glyoxal alone increased while the WRA decreased slightly.     

Effect of softeners and crosslinking conditions on the performance of easy-care cotton fabrics with different weave constructions

This study reports an experimental investigation on the effect of softeners, crosslinking conditions, and laundering on the comfort related and low stress mechanical properties of cotton fabrics with different weave constructions. Softeners with different chemical natures, in conjunction with the crosslinking agent and catalyst, were padded onto the cotton fabrics of three types of weave constructions, viz. plain, twill, and a newly developed plant-structured weave design. Two crosslinking conditions, namely dry and moist curing conditions, were compared. Scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscope were used to visualize and quantify the morphological and chemical changes on fabrics. The experimental results showed that the dry-crosslinking condition is preferable to achieve better comfort and easy-care properties, while moist-crosslinking condition is a better choice when strength-related properties are the main requirement. The study further showed that silicone elastomer softener can be applied to improve fabric strength whereas micro-emulsion of functional amino-polysiloxane plus emulsion containing polyalkylene is beneficial for comfort characteristic. The plant-structured cotton fabric finished in the dry-crosslinking condition with softener in nano-emulsion form can result in superb water absorption, excellent air permeability, good handle, acceptable strength, and improved easycare property.     

Formaldehyde free cross-linking agents based on maleic anhydride copolymers

Low molecular weight copolymers of maleic anhydride and vinyl acetate were prepared to develop formaldehyde free cross-linking agents. Since lower molecular weight is favorable for efficient penetration of the finishing agent into the cotton fibers in the padding process, the concentration of the initiator, chain transfer agent and the monomer ratios were varied to obtain copolymers of low molecular weights. The prepared polymers were characterized by GPC,¹H-NMR, FTIR, DSC and TGA. Copolymers of molecular weights of 2 000 to 10 000 were obtained and it was found that the most efficient method of controlling the molecular weight was by varying the monomer ratios. Poly(maleic anhydride-co-vinyl acetate) did not dissolve in water, but the maleic anhydride residue hydrolyzed within a few minutes to form poly(maleic acid-co-vinyl acetate) and dissolved in water. However, the maleic acid units undergo dehydration to form anhydride groups on heating above 160 °C to some extent even in the absence of catalysts. The possibility of using the copolymers as durable press finishing agent for cotton fabric was investigated. Lower molecular weight poly(maleic anhydride-co-vinyl acetate) copolymers were more efficient in introducing crease resistance, which appears to be due to the more efficient penetration of the crosslinking agent into cotton fabrics. The wrinkle recovery angles of cotton fabrics treated with poly(maleic anhydride-co-vinyl acetate) copolymers were slightly lower than those treated with DMDHEU and were higher when higher curing temperatures or higher concentrations of copolymer were used, and when catalyst, NaH₂PO₂, was added. The strength retention of the poly(maleic anhydride-co-vinyl acetate) treated cotton fabrics was excellent.     

Preparation of Durable Antibacterial Cellulose with AgCl Nanoparticles

In this study, a facile method was developed to coat AgCl nanoparticles (NPs) onto knitted cotton fabrics. The AgCl NPs were characterized by ultraviolet absorption spectrum, X-ray diffraction (XRD) and dynamic laser light scattering (DLS). The AgCl NPs were coated onto cotton fabrics through a pad-dry-cure process with the assistance of 1,2,3,4- butanetetracarboxylic acid (BTCA). Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), ICP-OES analysis and energy-dispersive X-ray spectroscopy (EDX) confirmed that AgCl NPs were successfully coated onto cotton fabrics. The prepared cotton samples exhibited excellent antimicrobial activity against both Gram-positive S. aureus and Gram-negative K. pneumonia bacteria. Rat skin fibroblast cytotoxicity testing demonstrated the treated cotton fabrics to be non-toxic. The washing durability evaluation showed that the antimicrobial function of cotton fabrics was durable to washing. In addition, the wrinkle resistance of the coated cotton fabrics was improved and there was no obvious change in whiteness.     

Process optimization of Aerva lanata extract treated textile material for microbial resistance in healthcare textiles

The focus of the present research work is on evaluation of the antimicrobial finished textile material from the extract of Aerva lanata plant and optimization of process parameters to get the maximum antimicrobial efficiency. The microencapsulated extracts of Aerva lanata plant (leaves and stalk) using citric acid as a cross linking agent were applied on plain-woven cotton fabric by pad-dry-cure method. The Aerva lanata extract treated fabric samples were tested for antibacterial activity against bacterial strains of Staphylococcus aureus and Escherichia coli under Agar diffusion test and AATCC 100–2004. It is observed that the treated cotton fabric shows a clear microbial resistance of about 19–25 mm zone of inhibition in the agar diffusion test against the above-mentioned bacterial strains. The treated samples showed 80 % of reduction against Staphylococcus aureus and 70 % reduction against Escherichia coli as per AATCC (100–2004). Process parameters like concentration of extract, citric acid and curing temperature were optimized using Box-Behnken design for better performance of antimicrobial treated material. The optimum values of 21.14 % extract concentration, 2.39 % crosslinking agent and 101.2 °C curing temperature were determined.     

Durable press finish of cotton via dual curing using UV light and heat

Continuous photografting/crosslinking of polyethyleneglycol dimethacrylate oligomers onto cotton using a water-soluble benzophenone photoinitiator was investigated. Photografting increased with increasing irradiation dose, oligomer concentration and photoinitiator concentration. Maximum grafting efficiency of DM 400 and 600 were 83% and 79%, respectively. The photografting increased the wrinkle resistance of cotton implying surface crosslinking of cotton. Both surface crosslinking and bulk crosslinking of cotton were accomplished via dual curing of a mixed formulation containing both a thermally curable component (BTCA/SHP) and a UV-curable component. The wrinkle resistance of the crosslinked cotton was found to be higher when cured by thermal curing after UV curing rather than by UV curing after thermal curing due to the facile post-polymerization of the UV active component. The presence of crosslinks in the dually crosslinked cotton was verified with FT-IR and thermogravimetric analysis.     

Study on antibacterial and comfort performances of cotton fabric finished by chitosan-silver for intimate apparel

The fabric used for intimate apparel is widely required to have excellent antibacterial and comfort performances. In order to improve its antibacterial ability, this paper studied chitosan-silver finishing on the cotton knitted fabric. The study indicates that the chitosan-silver attached to the fabric exhibits excellent antibacterial action against the typical bacteria of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureu). The anti-bacterial mechanism of chitosan-silver against E. coli and S. aureu were investigated. To guarantee its prominent comfort performance, measurements were made on the finished fabric of its air permeability, water vapor transmission, hydrophily, surface friction and bending ability against the control fabric, which is currently used for intimate apparel. The antibacterial and comfort performances were compared between the tested fabrics. The results show that the air permeability and the hydrophily of the finished cotton fabric are significantly better than the control one, while the water vapor transmission, the surface friction and the adjustable rate remain similar to each other. The bending rigidity of the finished fabric is slightly better due to the attachment of chitosan within accepted threshold. The dual compounding theory of chitosan-silver proves to be useful for a higher synergistic effect of anti-bacteria, lower whiteness degradation and overall optimization of comfort performance. This dual compounding theory of chitosan-silver is valuable for improving antibacterial and comfort performances of intimate apparel.     

Cotton fabric mechanical properties affected by post-finishing processes

Following the work done previously [1]. In this paper, the effect of various post-finishing agents on the low stress mechanical and surface properties of dyed cotton fabrics, as well as their handle value have been studied. The mechanical properties of the treated cotton fabrics were measured by the famous KES-FB system. It has been found that cotton fabric mechanical properties and fabric handle can be modified by not only the external finishing agents but also the internal finishing agents which are used for correcting the inherent defect of the fabrics. The results in this report will inform the textile industry in engineering required fabric properties with appropriate finishing processes.