Co-application of hydroxyalkyl dyes and polyphosphonic acids to cotton to achieve dye—fibre covalent bonding

The dyeing of cotton to a high standard of wet-fastness with hydroxyalkyl dyes and a polyphosphonatecrosslinker system has been investigated. Dyes containing hydroxyalkyl groups were prepared, by the reaction of commercial reactive dyes with ethanolamine, and applied to cotton fabric in the presence of polyphosphonic acid crosslinking agents using cyanamide as a catalyst. The application was carried out using a pad-thermosol method. The effects of cyanamide concentration, the nature of the crosslinker and the type of hydroxyalkyl dye were studied in detail. It was concluded that multifunctional polyphosphonates are capable of producing dyeings on cellulosic fibres exhibiting a high degree of covalent bonding (fixation). The efficiency of dye fixation at ca. 2% pure dye (owf), obtained from this method, was greater than 90%.     

双一氟三嗪活性染料的染色方法与染色性能

合成了一支含双一氟三嗪活性基团的活性染料并应用于棉纤维的染色。详细考察了染色温度、固色温度、加碱量以及加盐量对其染色结果的影响。结果表明,在染色温度90℃,Na2SO4用量70g/L,固色温度40～60℃,碱量（Na2CO3）0～3 g/L时染料的固色率可以达到87%。与同结构的含双一氯均三嗪活性染料相比,含氟活性染料的固色率提高13.5%。该染料具有较好的各项牢度性能。     

降解壳聚糖在棉织物活性染料低盐染色中的应用

采用降解壳聚糖对棉织物进行预处理,比较处理前后棉织物活性染料染色的上染率、固色率及耐摩擦牢度,在此基础上研究低盐工艺对棉织物活性染料染色的上染率、固色率的影响。实验结果表明降解壳聚糖预处理棉织物显著改善活性染料染色性能,提高染料上染率,减少了染整加工过程中对环境造成的污染。降解壳聚糖预处理的最佳工艺条件:浸渍温度80℃、降解壳聚糖用量0.8%(owf)、浸渍时间30 min。     

Concurrent dyeing and finishing: V. One-bath dyeing and easy-care finishing of cotton fabrics with acid dyestuffs and N-methylol compounds using different catalytic systems

A number of catalysts have been used for effecting concurrent dyeing and easy-care finishing of cotton fabric with acid dyes and N-methylol finishing agents. Factors affecting the process, such as the nature and concentration of catalyst, the finishing agent, the additive and the dye as well as curing temperature, were investigated. Evaluation of the simultaneously dyed and finished fabric was made with respect to colour strength, wrinkle recovery and fastness properties. The results obtained indicate that, of the eleven catalysts used, ammonium persulphate is the best for effecting concurrent dyeing and finishing of cotton fabric using acid dye and dimethyloldihydroxyethylene urea (DMDHEU).     

Fixation of reactive dyes using radio-frequency energy

Radio-frequency (r.f.) energy has been used to increase the fixation rate of reactive dyes on cotton fabric in pad-batch dyeing. A parallel-plate r.f. applicator was used to heat batches of fabric containing reactive dye formulations. The time required for fixation of the dyes was reduced from several hours to a few minutes by heating the fabric in the radio-frequency field. Reactive dyes incorporating three different types of reactive groups, vinylsulphone, nicotinic acid, and mixed vinylsulphone/ monochlorotriazine were studied and found to be applicable using the hot pad-batch method. The colour yield and wash fastness of dyeings with the vinylsulphone/monochlorotriazine bifunctional dyes using r.f.-assisted fixation was equal or superior to those of dyeings performed by conventional cold pad-batch dyeing methods.     

Synthesis and dyeing properties of polyvinylamine dyes for cotton

Novel polyvinylamine dyes were designed and synthesised from poly(N‐vinylformamide‐co‐vinylamine) and reactive dyes, then used to dye cotton fibres by the dip‐pad‐steam process, with the dyeing methods being examined in detail. Each polyvinylamine dye was fixed to cotton without a crosslinking agent through covalent bonds formed between the reactive group of the dye and the cotton fibres. A fixation of 99% was achieved, with grades of 4 and 4‐5 wash and dry‐rub fastness, respectively.     

棉纤维化学改性与染色性能研究

棉纤维通过化学改性和交联作用，增加棉纤维与活性染料的反应能力，达到增深和提高染色牢度的目的。棉纤维染色中不仅需要进一步提高活性染料的固色率、改善其各项性能，而且要重视纤维活化改性和交联染色法的研究。     

Innovation and application of dyes with high fixation

Reactive dyes are the main species for cotton dyeing due to their wide range of hue, satisfactory color fastness and facile application method. Aiming at increasing fixation on cotton fibers, benzimidazolone yellow reactive dyes, sulfonamide red reactive dyes and anthraquinone azo blue reactive dyes are designed. The preparation, characterization and application properties of these dyes with high fixation are introduced in detail. In order to achieve dye fixation to near 100%, macromolecular cro...     

Optimal dyeing systems for resistance to the physical strength loss of the PLA/cotton blended fabric

In this study, optimization of disperse/reactive dyeing systems for resistance to the physical strength loss of Poly(lactic acid) (PLA)/cotton blended fabric was investigated. The blended fabric underwent a two‐bath, two‐stage dyeing process in which the PLA component of the blended fabric was dyed using two disperse dyes, followed by the cotton component being dyed with six reactive dyes containing different reactive groups—dichlorotriazine, monochlorotriazine, sulphatoethylsulphone, monofluorotriazine, monochlorotriazine/sulphatoethylsulphone, and monofluorotriazine/sulphatoethylsulphone groups. The optimal dyeing systems were established according to the fixation rate of the dyes, tear/tensile strength loss, and SEM micrographs of the fabric. To avoid the strength loss during the disperse/reactive dyeing process, the recommended disperse dyeing conditions were 110°C, pH 5 for 20 min, whereas the reactive dyeing conditions should be temperature ≤60°C and alkali concentration ≤3 g/L. In this regard, reactive dyes containing monofluorotriazine and monofluorotriazine/sulphatoethylsulphone groups were especially suitable for the reactive dyeing systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Cetylpyridinium chloride cationic finishing improves the dyeing and antibacterial properties of madder dyed cotton

In this work, after cationic pretreatment of cotton fabric with cetylpyridinium chloride (CPC), the compound of citric acid (CA) and succinic acid (SUA) were used as crosslinking agents to dye cotton fabrics with natural madder dye to improve the dyeing and antibacterial properties and realise the multifunctional finishing of cotton fabric. The effects of mordant dyeing, CA + SUA crosslinked dyeing, and CPC/CA + SUA crosslinked dyeing on the microstructure and properties of cotton fabrics were compared. The dyeing by the three processes occurred primarily in the amorphous zone of the fibres, and all kept the original crystalline form of the cotton. CA + SUA crosslinked dyeing and CPC/CA + SUA crosslinked dyeing increased the thermal stability of the cotton fabric. CPC/CA + SUA crosslinked dyed cotton obtained excellent dyeing results with the colour depth value (K/S) of 12.3 and rubbing fastness and washing fastness of levels 4–5, and the levelness and dye permeability were acceptable. Furthermore, the antibacterial rate against Escherichia coli and Staphylococcus aureus reached 99.99%, and the ultraviolet protection factor (UPF) reached 50+. Moreover, the wrinkle recovery angle (WRA) increased by 55% compared with raw cotton. This showed that CPC/CA + SUA crosslinked dyed cotton had excellent antibacterial, anti-ultraviolet, and anti-wrinkle performances.     

Dyeing of nylon 6 fabric with a new bifunctional vinyl sulphone reactive disperse dye

A new bifunctional reactive disperse dye containing a temporarily anionic sulphatoethylsulphone and a nonionic disulphide bis(ethylsulphone) groups was synthesised and applied to nylon 6 fabric by the exhaust dyeing at a variety of pH and temperature conditions. A monofunctional reactive disperse dye containing only nonionic disulphide bis(ethylsulphone) group was also synthesised and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and fixation values at pH 6 and 120 °C. The results also indicate that the combination of temporarily anionic and nonionic reactive groups of the bifunctional dye provided great enhancement in dyeing performance compared to that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

Application of polycarboxylic acid sodium salt in the dyeing of cotton fabric with reactive dyes

In this study, the effects of polycarboxylic acid sodium salt on the dyeing of cotton with reactive dyes were evaluated by measuring and comparing the K/S values and dyeing fastnesses of the dyed cotton fabric samples. Results showed that the K/S value and dyeing fastness of cotton fabrics dyed with polycarboxylic acid sodium salt, substituting inorganic salts as exhausting agent were close to that of with sodium chloride when dip‐dyeing process was used. While, in pad‐dry dyeing, the K/S value of cotton fabric samples dyed with polyacid salts as exhausting agent was higher than that of with sodium sulfate, and the dyeing fastnesses of these samples were nearly the same. The dyeing mechanism of cotton fabric with reactive dye, using polycarboxylic acid sodium salt as exhausting agent was analyzed. The dyeing exhausting mechanism of reactive dye seems different when the inorganic salt and polycarboxylic acid sodium salt were used as exhausting agent in the dyeing of cotton fabric with reactive dye. The polycarboxylic acid sodium salt, as weak electrolyte, increased the dye‐uptake of reactive dye on cotton fabric not only by screening negative charges on cotton surface, but also by the effect of salting‐out or hydrophobic combination. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Pretreatment of cotton with poly(vinylamine chloride) for salt-free dyeing with reactive dyes

Poly(vinylamine chloride) has been investigated as a pretreatment for the salt-free dyeing of cotton with reactive dyes. Dye fixation was found to be much higher than by conventional dyeing without pretreatment, even in the presence of a large amount of salt. The influence of pretreatment conditions on dye fixation, such as pad–bake variables and the concentration of poly(vinylamine chloride), has been studied. The dyeing behaviour of CI Reactive Red 2 on pretreated cotton was examined and found to follow a Langmuir-type adsorption curve. Dyed cotton pretreated with poly(vinylamine chloride) showed excellent wash fastness and good rub fastness. It is concluded that poly(vinylamine chloride) is effective as a pretreatment for salt-free dyeing with reactive dyes.     

Synthesis of reactive dyes based on the bis-(N-carboxymethylamino)monoquaternary-triazine-bis-ethylsulphone reactive group. Part 1: Application to cotton cellulose

Reactive dyes containing the bis-( N -carboxymethylamino)monoquaternary-triazine-bis-ethylsulphone [bis-( N -CMA)-MQT-bis-ES] group and related derivatives have been synthesised. When boiled under mildly acidic conditions, such dyes are able to form two small vinylsulphone dye molecules through a process of 1,2-trans elimination. The bis-( N -CMA)-MQT-bis-ES dye was applied using different dyeing procedures (novel dyeing methods 1 and 2). The dyeing and soaping-off results of bis-( N -CMA)-MQT-bis-ES dye were compared with a model sulphatoethylsulphone dye applied using the conventional alkaline fixation method used for applying this type of reactive dye to cotton. The bis-( N -CMA)-MQT-bis-ES dye showed higher exhaustion and fixation values applied using novel dyeing method 2 compared with the sulphatoethylsulphone dye applied using the alkaline fixation method. The soaping-off efficiency for the large bis-( N -CMA)-MQT-bis-ES dye applied using novel dyeing method 2 was the same as that obtained for the sulphatoethylsulphone dye applied using the alkaline fixation method.     

Dyeing and finishing of cotton fabric in a single bath with reactive dyes and citric acid

Simultaneous dyeing and durable press finishing of cotton fabrics with reactive dyes and citric acid finishing agent was carried out using a pad-dry-cure process. Factors affecting the process, such as the concentration of dye, citric acid, catalyst and alkali, as well as the curing temperature, were investigated. The dyed and finished fabrics were evaluated with respect to colour strength, crease recovery angle, breaking strength and fastness properties.     

槐米染色棉织物工艺及其抗紫外性能研究

为实现槐米染料的工业化应用及提高棉织物的功能性,分析了使用壳聚糖、Al3+、Fe2+媒染剂预媒染色法对棉织物染色效果的影响,重点研究了铝预媒染方法染色温度、染色时间、pH值等工艺参数对染色棉织物K/S值的影响,并测试了槐米染色棉织物的抗紫外性能。结果表明:直接使用槐米染色的效果较差;壳聚糖媒染对上染效果影响不大,使用铝、铁媒染剂,可得到不同颜色的棉织物;铝媒染剂染色棉织物为鲜艳的黄色,为较好的媒染方法;铝预媒染染色方法染色优化条件为:温度为80℃,染色时间120分钟,染浴pH值为6.8;铝预媒染染色棉织物具有较好的抗紫外性能。     

Improving easy care nonformaldehyde finishing performance using polycarboxylic acids via precationization of cotton fabric

Cotton fabric were first subjected to quaternization (cationization) reaction using 3‐chloro‐2‐hydroxypropyl trimethyl ammonium chloride commercially known as Quat®‐188. Cationization was carried out under different conditions for optimization of the preparation of cationized cotton with different degrees of cationization, using the pad‐batch method. Also, established was the optimal condition for cationization that involves Quat‐188/NaOH molar ratio 1/2 at 70°C for 4 h. Besides, a thorough investigation of factors affecting reaction of these cationized cotton with citric acid (CA) or 1,2,3,4‐butanetetracarboxylic acid (BTCA) was carried out with a view of improving the ease of care characteristics of nonformaldehyde finishing. The dependence of fabric performance as measured by strength properties, dry wrinkle recovery angles, whiteness index, and dyeability with reactive dyes was also evaluated. It was postulated that reaction of cationized cotton with either CA or BTCA involves estercrosslinking as well as ionic crosslinking. This, indeed, was largely positively reflected on the fabric performance especially when the properties of both uncationized cotton were compared with those of the cationized cotton. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2697–2704, 2006     

Synthesis and application to cotton of a polymeric black colorant prepared by grafting of reactive dyes to polyvinylamine

A novel polymeric black dye was synthesised by grafting yellow, orange, red, and blue reactive dyes onto polyvinylamine. Such a polymeric black dye takes the onus away from dyers to worry about the compatibility of individual dyes. The polymeric black dye was characterised by Fourier transform infrared, ultraviolet‐visible, and nuclear magnetic resonance spectroscopy. The absorption of the polymeric black dye in aqueous solution was nearly constant across the wavelength range 400–700 nm. Compared with a black mixture of reactive dyes with low fixation on cotton, which was prepared by mixing yellow, orange, red, and blue reactive dyes, the polymeric black dye reached 99% fixation on cotton through the use of a crosslinking agent. The colorimetric properties of cotton dyed with the polymeric black dye and with the black mixture of reactive dyes showed that better blackness can be obtained by using the polymeric black dye. Analysis of the thermal stability and penetration ability of the polymeric black dye showed that the polymeric dye has high stability in the application and a uniform distributution in the cotton fabric.     

Dyeing of nylon 6 fabric with a bifunctional sulphatoethylsulphone reactive disperse dye

A bifunctional reactive disperse dye containing two temporarily anionic sulphatoethylsulphone groups was synthesised and applied to nylon 6 fabric by exhaust dyeing at a variety of pH levels and temperatures. A monofunctional reactive disperse dye containing one temporarily anionic sulphatoethylsulphone group was also synthesised, and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and total fixation yield under alkaline conditions. The results also indicate that the introduction of two temporarily anionic sulphatoethylsulphone groups of the bifunctional dye gave an enhancement in dyeing performance compared with that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

Deep‐coloured polyester/cotton blends with low concentrations of polymethylol dyes by a one‐pass continuous dyeing process

An obvious limitation of the one‐pass continuous dyeing process for polyester/cotton blends is its inability to achieve deep colour depth, which is caused by the low dye fixation yields of commercial reactive dyes. In this study, the performances of polyester/cotton blends dyed with high‐fixation polymethylol dyes and disperse dyes were compared with those of polyester/cotton blends dyed with a mixture of reactive dyes and disperse dyes. Polymethylol dyes were observed to be suitable for dyeing polyester/cotton blends when used in low concentrations; the required concentrations of polymethylol dyes were only 23–58% of the concentrations of commercial reactive dyes required to reach a given colour level on polyester/cotton blends. The wash and crocking fastness of polyester/cotton blends dyed with polymethylol dyes were similar to those of polyester/cotton blends dyed with reactive dyes.