Dyeing of polyester using micro-encapsulated disperse dyes in the absence of auxiliaries

Polyurea microcapsules were prepared in this study, using disperse dye as the core material and diphenylmethane-4,4'-diisocyanate as the wall-former. Microencapsulated disperse dyes have been characterised in terms of their thermal properties, average particle size and size distribution, morphological structure and composition. Polyester fabric was dyed with microencapsulated CI Disperse Blue 56 using a high temperature dyeing process without dispersing agents, penetrating agents, levelling agents or other auxiliaries. The quality of the polyester fabric dyed in this manner – without reduction clearing – was at least as good as that dyed traditionally after washing and reduction clearing. After separating off the polyurea microcapsules, the dyebath was virtually colourless and was shown to be suitable for reuse.     

Studies on the possibility of recycling microencapsulated disperse dye‐bath effluents

The volume of water consumed by human beings has increased dramatically in recent years while water supply has remained constant; both demographic growth and the expansion of industrial activity require more water consumption. The textile industry is undoubtedly one of the most pressured industries that need water intensively. Efficient use of water tends to be a crucial subject for the dyeing industry. In this study, melamine resin microcapsules containing pure disperse dyes were prepared by in situ polymerization. The microcapsules were characterized on the basis of structure, morphologies, mean particle size, and size distribution. The dyeing behaviors of microencapsulated disperse dyes (MDDs) were evaluated on polyester fabrics in the absence of auxiliaries. Its effluent can be reused several times after being simply filtered and can be used as solvent for PET fabric scouring. The treated fabrics exhibited satisfactory levelness and fastness properties. MDDs can be used in dyeing PET, without using surfactants, and the effluents can be recycled and reused. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

低聚物对聚酯织物分散染料染色废液COD_(Cr)的影响

采用原位聚合法在不同芯壁比条件下对纯分散染料进行微胶囊化,将其对溶剂萃取过低聚物的TTT及PET织物进行染色,采用紫外分光光度法测定染色废液CODCr值,并与相应的商品分散染料染色废液CODCr值进行比较.结果表明,低聚物的存在将增大PTT及PET织物染色废液的CODCr值;对于相同分散染料,芯壁比为1:2的微胶囊染色废液CODCr值大于芯壁比为1:4的微胶囊染色废液CODCr值;微胶囊分散染料染色废液CODCr值远低于相应商品分散染料的染色废液CODCr值.     

Effect of microencapsulation on dyeing behaviors of disperse dyes without auxiliary solubilization

Microencapsulated disperse dye can be used to dye hydrophobic fabric in the absence of auxiliaries and without reduction clearing. However, little available information for dyeing practice is provided with respect to the effect of microencapsulation on the dyeing behaviors of disperse dyes. In this research, disperse dyes were microencapsulated under different conditions. The dyeing behaviors and dyeing kinetic parameters of microencapsulated disperse dye on PET fiber, e.g., dyeing curves, build up properties, equilibrium adsorption capacity C_∞, dyeing rate constant K, half dyeing time t_1/2, and diffusion coefficient D were investigated without auxiliary solubilization and compared with those of commercial disperse dyes with auxiliary solubilization. The results show that the dyeing behaviors of disperse dye are influenced greatly by microencapsulation. The diffusion of disperse dyes from microcapsule onto fibers can be adjusted by the reactivity of shell materials and mass ratios of core to shell. The disparity of diffusibility between two disperse dyes can be reduced by microencapsulation. In addition, the microencapsulation improves the utilization of disperse dyes due to no auxiliary solubilization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and properties of disperse dye microcapsules

Microcapsules with a double-layered shell containing disperse dyes were prepared by means of in-situ polymerisation. Factors affecting the release performance of the microcapsules were investigated and the results are presented in this paper. The particle size distribution and thermal properties of the dye microcapsules were also investigated. A multiple-transfer printing technique using such dye microcapsules is proposed.     

Preparation of Aqueous Nanodispersions of Disperse Dye by High-Gravity Technology and Spray Drying

Disperse dyes are poorly water-soluble and difficult to stably disperse in an aqueous medium, which greatly limits their application in dyeing synthetic fibers. Micronization can solve this problem. Herein, a facile way to prepare stable aqueous nanodispersions of disperse dye (C.I. disperse yellow 54) is presented by combining high-gravity antisolvent precipitation in a rotating packed bed (RPB) with spray drying. The as-prepared product had an average particle size of 120 nm, which could be readily redispersed in water. Compared with raw dye, the wettability and dispersibility of disperse dye nanoparticles were remarkably improved. Furthermore, the dyeing properties of the nanodispersions were obviously better than those of the commercial dye, which was micronized by ball milling.     

Improved mechanism of polyester dyeing with disperse dyes in finite dyebath

A new sorption mechanism of polyester dyeing with disperse dyes in water is proposed. It is considered dye aggregates could not be sorbed unless they turn into single molecules. However, this theory could not explain numerous sorption phenomena: sorption continues when equilibrium dye concentration exceeds its solubility; dyeing at long liquor ratio, using microencapsulated or crystal‐modified dyes do not change concentration of single dye molecules or dye solubility, but increase sorption rate and quantity in a fixed time. We demonstrate that both single and aggregated dye molecules could be sorbed using CI Disperse Blue 56. Because of the large size and low diffusion rate, dye aggregates could temporarily block sorption channel and prevent entry of other dyes. Therefore, only using extra more dyes could get a dark colour. Series of approaches could be proposed to reduce or eliminate the sorption problems caused by aggregates using the new sorption mechanism.     

分散染料微胶囊粒径及其分布的影响因素

采用原位聚合法对分散染料进行微胶囊化,芯壁比、剪切乳化速率、反应搅拌速度、系统调节剂MS用量、单双层滴加单体时间都将对分散染料微胶囊的粒径大小和分布产生重要影响。     

Stabilisation and detoxification of henna (Lawsonia inermis L.) extract for hair dye cosmetics by spray‐drying encapsulation

Henna (Lawsonia inermis L.) leaves have been widely used as a natural plant colorant for hair dyeing and body art. However, the utilisation of henna dye extract in commercial colour cosmetics is compromised by its potential harmful effects to humans. This study demonstrates that spray‐drying encapsulation using maltodextrin and gum arabic as biocompatible polymeric carriers can be used as a promising strategy to detoxify henna dye extract while maintaining its hair dyeing efficiency for cosmetics. Henna extract‐loaded microcapsules with an average particle size of 4.1 μm were prepared with an excellent encapsulation efficiency (98.4%) and a negative zeta potential (?34.4 mV). The morphology and physicochemical properties of the microcapsules were characterised by comparison with a spray‐dried sample of neat henna extract. The in vitro toxicological results showed that the microencapsulation process significantly reduced the contact toxicity of henna extract towards human epidermal keratinocytes as well as to the eyes and skin. The encapsulated henna extract also exhibited improved storage stability at three different temperatures (4, 25 and 50°C) for 14 days. Furthermore, the microcapsules demonstrated satisfactory hair dyeing efficiency as natural colorants with good colour fastness towards light and washing.     

Synthesis and characterisation of microencapsulated 7‐alkyloxy‐4‐trifluoromethylcoumarin dyes

Five new 7‐alkyloxy‐4‐trifluoromethylcoumarin fluorescent dyes were synthesised using the Pechmann and Williamson etherification reactions. The structures of these coumarin dyes were characterised by Fourier Transform–infrared, proton and carbon nuclear magnetic resonance and mass spectra. One of the new coumarin compounds, 7‐isopropyloxy‐4‐trifluoromethylcoumarin, was microencapsulated with melamine–formaldehyde as the shell material by in situ polymerisation. The microcapsules were characterised in terms of Fourier Transform–infrared spectrum, particle size distribution and scanning electron microscopy morphology. The cotton fabric finished with the microencapsulated coumarin dye showed strong fluorescence under ultraviolet light.     

芳纶1313的超高温高压染色研究

本文采用超高温高压法对芳纶1313进行染色,分别研究了染料种类和染色温度对芳纶1313纱线染色日晒牢度、K/S值及染透性等方面影响,结果发现,分散染料所染纱线的各项染色性能都比阳离子染料和还原染料好;随染色温度升高,日晒牢度、纤维表面颜色深度及其纤维染透性都得到了不同程度的改善,而纱线的断裂强度随染色温度的升高变化不大。     

Synthesis and thermal properties of poly(n‐butyl acrylate)/n‐hexadecane microcapsules using different cross‐linkers and their application to textile fabrics

This study focused on the preparation, characterization, and determination of thermal properties of microencapsulated n‐hexadecane with poly(butyl acrylate) (PBA) to be used in textiles with heat storage property. Microcapsules were synthesized by emulsion polymerization method, and the particle size, particle size distribution, shape, and thermal storage/release properties of the synthesized microcapsules were analyzed using Fourier‐transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry techniques. Allyl methacrylate, ethylene glycol dimethacrylate, and glycidyl methacrylate were used as cross‐linkers to produce unimodal particle size distribution. MicroPBA microcapsules produced using allyl methacrylate cross‐linker were applied to 100% cotton and 50/50% cotton/polyester blend fabrics by pad‐cure method. The mean particle size of microcapsules ranges from 0.47 to 4.25 μm. Differential scanning calorimetry analysis indicated that hexadecane in the microcapsules melts at nearly 17°C and crystallizes at around 15°C. The contents of n‐hexadecane of different PBA microcapsules were in the range of 27.7–50.7%, and the melting enthalpies for these ratios were between 65.67 and 120.16 J/g, respectively. The particle size and thermal properties of microcapsules changed depending on the cross‐linker type. The cotton and 50/50% cotton/polyester blend fabrics stored 6.56 and 28.59 J/g thermal energy, respectively. The results indicated that PBA microcapsules have the potential to be used as a solid‐state thermal energy storage material in fabrics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Dyeing properties of polyamide super-microfibre with disperse dyes

The dyeing properties of polyamide super-microfibres and conventional fibres dyed with disperse dyes have been studied by measuring the adsorption isotherm, the rate of dye uptake, the time of half-dyeing and the amount of equilibrium adsorption. The thermodynamic analysis shows that the adsorption isotherms of super-microfibres follow a Langmuir sorption model. The kinetic results show that super-microfibres have a faster dyeing rate and a higher equilibrium dye uptake compared to conventional fibres. This can be explained by the greater surface area and dye capacity of the super-microfibres. The wash and light fastness properties of the super-microfibres dyed with disperse dyes are lower than conventional fibres.     

聚对苯二甲酸丙二酯纤维的染色性能

根据Shell公司和Dystar公司的研究,用Optidye系统从分散染料吸附与上染率、染色温度、pH值、匀染性及染色牢度等方面解析了聚对苯二甲酸丙二酯(PTT)纤维的染色性能。PTT纤维在100℃就可染到深色,在60～80℃和90～100℃有两个吸附速度较快区域;PTT纤维属易染型纤维,在最高温度染保持30～40min即可。高温型分散染料在120℃染色,常压100℃染色无需pH值调节。分散染料染色牢度(洗涤、摩擦及耐光)非常好。     

Modification of cellulose acetate fabric with cyclodextrin to improve its dyeability

Cellulose acetate fibers are usually dyed with disperse dyes in the presence of various additives to ensure coloration leveling. The possibilities of formation of complexes between disperse dye molecules and cyclodextrin (CD) can be of beneficial use. In this respect, the modification of the fiber with CD, then subjecting it to dyeing with disperse dye was performed on the basis of host/guest system as an alternative to overcome the low solubility of disperse dyes in water. The additives of the dyeing bath can be eliminated. The attained color intensities as well as the fastness properties are enhanced upon using CD. The depth of the dye inside the fiber structure is highly enhanced, while the thermal properties such as the glass transition temperature, crystallinity temperature, and melting temperature remain nearly constant. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Microencapsulation and application of fluorine‐free water repellent agent‐AH102

Fluorine‐free water repellent agent, AH102, was microencapsulated by interfacial polymerization with polyurethane as shell material to restrict its hydrolysis and improve its dispersibility in water. The appearance of the resultant microcapsules was characterized with optical microscope and scanning electron microscope. Chemical structure of microcapsules was identified with Fourier‐transforming infrared spectrometer. The size and size distribution of the microcapsules were determined by laser particle size analyzer. The thermal property of the microcapsules was investigated by thermogravimetric analysis. The stability and dispersibility of the microcapsules in aqueous medium were characterized by evaluating the static water contact angles of the treated cotton fabrics with the emulsions of unencapsulated and microencapsulated AH102 at different storage intervals. The results showed that AH102 was successfully encapsulated and its stability and dispersibility in water were greatly improved. As expected, the emulsion of the microencapsulated AH102 became more stable than that of the unencapsulated one at water repellence to cotton fabric with increasing storage intervals. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The roles of elevated temperature and carriers in the dyeing of polyester fibres using disperse dyes: Part 1 fundamental aspects

This review concerns the application of disperse dyes to poly(ethylene terephthalate) (PET) fibres using aqueous immersion dyeing processes and the roles of both elevated dyeing temperatures and carriers in such dyeing systems. This part of the paper presents a review of the fundamental properties and characteristics of PET fibres, disperse dyes and dyeing accelerants. In the next part of the paper, the various theories and concepts that have been proposed to explain the promotional effects imparted by elevated dyeing temperatures and carriers to disperse dye uptake on PET and other types of fibre, are reviewed and analysed, from the viewpoints of the essential physico-chemical aspects of both the aqueous disperse dye/PET and disperse dye/carrier/PET systems. Later parts of the paper will present a mechanistic model of the disperse dye adsorption process based on dye solubility as well as a novel plasticisation model of dye diffusion.     

含微胶囊相变材料的海藻酸钙大胶囊的制备及其性能

采用原位聚合法合成了微胶囊相变材料,并通过锐孔法制备了海藻酸钙包覆多个微胶囊相变材料的大胶囊。用FTIR分析了大胶囊的化学结构,采用游标卡尺测量在不同质量分数的海藻酸钠水溶液和氯化钙水溶液中制备的大胶囊的平均粒径;用SEM和DSC对微胶囊相变材料的微观形貌和热性能进行了分析,对大胶囊的热性能进行了考察,讨论了在不同海藻酸钠质量分数下制备的大胶囊经甲苯萃取30 m in后的热性能。结果表明,微胶囊呈粒径均一,表面光滑,密封较好的球体;其相变温度为34.1℃,相变潜热为143.8 J/g。随着微胶囊相变材料加入量的增加,大胶囊的相变潜热逐渐增加;当w(CaC l2)=2%时,随着海藻酸钠质量分数的增加,大胶囊的粒径由1.36 mm逐渐增加至1.96 mm并趋于平缓,且海藻酸钠水溶液质量分数不宜超过3%;随着氯化钙质量分数的增加,大胶囊平均粒径逐渐增长,但幅度较其随海藻酸钠质量分数变化的幅度小;甲苯对大胶囊壳材的渗透能力随海藻酸钠质量分数的增加而减小。     

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.     

石蜡相变微胶囊的制备及性能研究

摘 要：以石蜡为芯材,蜜胺树脂(MF)为壁材,采用原位聚合法制备了石蜡相变微胶囊。采用傅里叶红外光谱仪（FT-IR）、扫描电子显微镜（SEM）、激光粒度分析仪和差示扫描量热仪(DSC)对微胶囊的性能和形貌进行了分析和表征,讨论了甲醛与三聚氰胺的摩尔比（F/M）对微胶囊性能和形貌的影响。实验结果表明,F/M摩尔比大于4时,微胶囊之间发生粘结,出现了团聚现象;微胶囊的相变温度略高于芯材石蜡,随着F/M摩尔比增加,微胶囊的相变潜热降低。