Influence of wool bleaching with hydrogen peroxide on dyeing with CI Acid Blue 80

This study investigates the influence of wool bleaching with hydrogen peroxide on the kinetics of wool dyeing, using a milling dye CI Acid Blue 80. The dyeing kinetics were studied at different temperatures on both unbleached and bleached wool [15 and 30 ml hydrogen peroxide (35% w/w)] and the following parameters determined: kinetics of adsorption, diffusion coefficient and apparent activation energies of the dyeing system for each type of wool. The results show that the values of these parameters are greater for the unbleached wools than for the bleached ones and that the values decrease as the bleaching intensity increases.     

Comparison of stabilisers for wool bleaching with hydrogen peroxide

The physico-chemical, environmental and bleaching properties of three different stabilisers for use in wool bleaching with hydrogen peroxide have been compared. The various factors influencing stabiliser choice are discussed.     

Comparison of wool bleaching with hydrogen peroxide in alkaline and acidic media

A merino wool top was bleached in both alkaline and acidic media, varying the hydrogen peroxide concentration in the bleaching bath. For the same peroxide concentration, bleaching in an alkaline medium leads to a whiter and more chemically attacked wool than bleaching in an acidic medium. For the same chemical attack, wool bleached in an alkaline medium is whiter than for bleaching in an acidic medium.     

Influence of surfactants on the electroreduction of oxygen to hydrogen peroxide in acid and alkaline electrolytes

The effect of surfactants on the electroreduction of O₂ to H₂O₂ was investigated by cyclic voltammetry and batch electrolysis on vitreous carbon electrodes. The electrolytes were either 0.1 M Na₂CO₃ or 0.1 M H₂SO₄ at 295 K, under 0.1 MPa O₂. Electrode kinetics and mass transport parameters showed the influence of surfactants on the O₂ electroreduction mechanism. The cationic surfactant (Aliquat 336^®, tricaprylmethylammonium chloride), at mM levels, increased the standard rate constant of O₂ electroreduction to H₂O₂ 15 times in Na₂CO₃ and 1900 times in H₂SO₄, to 1.8 × 10^–6 m s^–1 and 9.9 × 10^–10 m s^–1, respectively. This effect on the reaction rate might be due to an increase of the surface pH, induced by the Aliquat 336^® surface film. The nonionic (Triton X-100) and anionic (sodium dodecyl sulfate) surfactants retarded the O₂ electroreduction, presumably by forming surface structures, which blocked the access of O₂ to the electrode. Ten hour batch electrosynthesis experiments performed at 300 A m^–2 superficial current density, 0.1 MPa O₂, 300 K, on reticulated vitreous carbon (30 ppi), showed that compared to the values obtained in the absence of surfactant, mM concentrations of Aliquat 336^® increased the current efficiency for peroxide from 12% to 61% (0.31 M H₂O₂) in 0.1 M Na₂CO₃ and from 14% to 55% (0.26 M H₂O₂) in 0.1 M H₂SO₄, respectively.     

Adsorption of ionic and non-ionic surfactants by wool charring waste

The effect of pH and temperature on the adsorption of anionic, cationic, and non-ionic surfactants on wool charring waste has been investigated in order to assess the optimum conditions of substrate use in water pollution control. The analysis of adsorption kinetics in aqueous media and in water-alcohol mixtures, allowed different adsorption mechanisms to be characterised. Plots of the amount of surfactant adsorbed against the square root of time provided information on the diffusion processes. The effect of the chain length on the adsorption of alkylsulphates on wool charring waste corroborated the importance of hydrophobic interactions.     

Low‐temperature bleaching of cotton fabric using a copper‐based catalyst for hydrogen peroxide

Hydrogen peroxide can be catalysed to bleach cotton fibres at a temperature of 70 °C by incorporating the copper‐based catalyst [Cu(TPMA)Cl]ClO₄·1/2H₂O in the bleaching solution. The effects of pH, temperature, and concentration of catalyst and hydrogen peroxide on bleaching effectiveness were evaluated. The effects of other transition metal complexes of tris(2‐pyridylmethyl)amine were also examined. The bleaching mechanism was investigated by studying the active species. The results showed that a satisfactory whiteness index could be obtained at low temperature with the copper‐based catalyst, and it also had a competitive advantage in protecting cellulose from severe chemical damage. Cu(i )TPMA(OOH)^? was the active species in bleaching.     

Effect of hydrogen peroxide bleaching onto sulfonated jute fiber

Bleaching of raw and sulfonated jute fiber with hydrogen peroxide were carried out in an aqueous medium. To obtain the optimum condition for bleaching, the effects of hydrogen peroxide concentration, temperature, time, pH, and fiber–liquor ration were studied. Bleaching affected the whiteness and tenacity, and the optimum whiteness index (76) and tenacity (13.7 g/tex) for the bleached sulfonated jute fiber were obtained with 2.1% hydrogen peroxide at pH 11, temperature 95°C, treatment time 110 min, and fiber–liquor ratio 1 : 7. The photo‐oxidative degradation of bleached sulfonated jute fiber was characterized by UV light exposure and compared with that of bleached raw jute fiber. It has been observed that the photo‐oxidative degradation as well as loss in tenacity and yellowness of the bleached sulfonated jute fiber was 63 and 40% lower than that of bleached raw jute fiber. Bleached sulfonated jute fiber had excellent impact on color fastness with reactive dyes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3603–3607, 2006     

Kinetics of hydrogen peroxide bleaching of ALCELL® derived pulp

In this study, a kinetic model of the final bleaching stage with hydrogen peroxide in a totally chlorine free (TCF) bleaching sequence for ALCELL® processed pulp was developed. The model was based on the rate of chromophore destruction characterized by the decrease in the light absorption coefficient of bleached pulp at 457 nm, C_K. Based on the fact that the chromophore destruction proceeds rapidly in an initial phase followed by a much slower reaction during which a “floor-level” chromophore concentration is approached asymptotically, we propose that the hydrogen peroxide stage of the ALCELL® derived pulp in the studied TCF sequence consists of two distinct phases. The initial phase is a very fast reaction. The rate equation of the second phase was determined as: which is valid in a pH range of 10.5 to 11.5 and a temperature range of 60 to 92.5°C.     

烷基多苷的过氧乙酸漂色及组合漂色工艺研究

对烷基多苷(APG)的过氧乙酸(CH3COOOH)漂色工艺进行了优化,优化条件是:烷基多苷(APG)水溶液的浓度为50%,CH3COOOH用量为5%,漂色时间90 m in,漂色温度80℃,初始pH 12~12.5。在此条件下漂色,可使APG水溶液的消光系数由6~7降至0.4左右;采用质量分数分别为3%的H2O2与CH3COOOH组合漂色,可使漂色效果进一步提高;对H2O2与CH3COOOH漂色前后的APG样品进行了红外光谱对比分析。     

Performance of a new cationic bleach activator on a hydrogen peroxide bleaching system

The performance of a cationic bleach activator, N -[4-(triethylammoniomethyl)benzoyl]caprolactam chloride, was evaluated in a hot peroxide bleaching process. The effect of time, temperature and the concentrations of hydrogen peroxide and activator on the bleaching of cotton fabric was investigated using a central composite experimental design. Temperature was found to be the most significant parameter. By adding the cationic activator it was possible to achieve a level of whiteness comparable to a typical commercial bleaching system but under relatively mild conditions of time and temperature. As a consequence, chemical damage to the fabric could be reduced. The effect of the cationic bleach activator was compared to that of an anionic activator, nonanoyloxybenzene sulphonate. The cationic activator was superior to the anionic activator in bleaching the fabric under the optimised conditions used in the study. Received: 13 January 2004, Accepted: 10 March 2004     

A simple method for the objective characterisation of fabric softness. Part 1: Influence of bleaching,dyeing and crosslinking of wool*

A simple method for the characterisation of fabric softness using a conventional tensile tester and a special measurement device has been developed. The method is demonstrated to be especially useful in detecting changes in softness of a given substrate due to different treatments. The results obtained, particularly hysteresis at 75% of the maximum extension, provide a good correlation with subjective ranking for samples that are subjectively distinguishable; they also differentiate well between samples which seem subjectively indistinguishable. Screening tests were carried out, mainly on wool fabrics, to find the effect of different treatments such as oxidative (alkaline and acidic) and reductive (Blankit IN) bleaching, dyeing with acid and a 1:2 metal complex, chrome and (mono and bi)reactive dyes, the effect of the antisetting agent Basolan AS (BASF) and of crosslinking with Irgasol HTW (CGY) on fabric softness.     

Improving the hydrophilic properties of wool fabrics via corona discharge and hydrogen peroxide treatment

Corona discharge has been widely applied to modify the surfaces of polymers. In this study, corona discharge was combined with a hydrogen peroxide treatment to improve the hydrophilic properties of wool fabric. Scanning electron microscopy photographs showed that the tip of wool scales was etched after corona discharge and that parts of the scales were peeled off after the hydrogen peroxide treatment. The surface hydrophilic properties of the wool fabric were improved greatly by corona discharge. Increases in the discharge voltage and the number of treatment passages enhanced the hydrophilic properties dramatically, but the improved properties deteriorated with increases in the number of washing cycles and storage time. The hydrogen peroxide treatment could improve the hydrophilic properties and especially the wicking properties of the wool fabric. The fabric became weaker and flexible with an average weight loss of 3% after the hydrogen peroxide treatment. A combination of corona discharge treatment and the hydrogen peroxide treatment made the wool fabric absolutely hydrophilic; the water penetration time of the treated fabric was less than 1 s even when the fabric was washed for several cycles or stored for 6 months. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Mg(OH)2引入方式对纸浆过氧化氢漂白工艺的影响

引言制浆造纸工业是废水和污染物排放的重要源头之一。传统含氯漂白会产生多种难降解、对环境具有高危害的含氯有机化合物,因此它们正在被过氧化氢漂白等无氯漂白工艺所取代。纸浆中的过渡金属离子可催化过氧化氢无效分解并形成对纤维素破化性强的自由基,因此常采用漂前酸洗、螯合及漂白保护剂等来消除和抑制过渡金属离子的影响。而如何使保护剂的功效得到更好的发挥,是     

Investigation into the synergistic effect between UV/ozone exposure and peroxide pad—batch bleaching on the printability of wool

The synergistic effect between UV/ozone exposure and hydrogen peroxide pad-batch bleaching on the printability of wool has been investigated. The combination treatment can achieve similar printability to that of chlorinated wool but with the added benefits of a whiter base and no formation of adsorbable organohalogens. X-Ray photoelectron spectroscopy and static secondary ion mass spectrometry indicate that the UV/ozone exposure disrupts surface lipids and disulphide bonds, while vibrational spectroscopy (FT-IR and FT-Raman) shows the formation of cysteic acid on the combination treated wool. The process parameters of the peroxide pad-batch bleaching for UV/ozone exposed wool were optimised.     

羊毛精纺织物性能满意度的评判

羊毛精纺织物是具有广泛用途的纺织产品,随着服饰文化越来越受到人们的重视,毛织面料的优选显得至关重要。本文应用多属性目标决策的方法,评判不同规格毛织面料的“满意度”,客观地提供一个重要的优选辅助依据。     

The effects of residual surfactants on the dyeing of wool

Wool fabric was extracted with various organic solvents at their boiling points and then dyed with Coomassie Blue BL200. Non–dyed areas of fabric were observed after extraction with ethanol, acetone/ water (70:30) and chloroform/methanol (70:30) mixtures, but not after extraction with perchloroethylene. Silica column chromatography separated the extracts from various solvent pretreatments into five major peaks, based on mass obtained. Some of these peaks were shown to contain cholesterol, non–ionic surfactant and phospholipid. Up to 14 components were detected by two–dimensional thin layer chromatography of the extracts. Thin layer chromatography revealed that some of the more polar components were not extracted by perchloroethylene. Separation of the extracts by column chromatography enabled a study of dye uptake to be carried out after recontamination of pretreated fabric with the major fractions. Materials in two of these fractions were found to eliminate the uneven dyeing observed with Coomassie Blue BL200. Column chromatography and spot tests showed that they behaved similarly to the non–ionic surfactant Antarox CO 630. These experiments also showed that refluxing perchloroethylene extracted only about half as much non–ionic surfactant as did refluxing chloroform/methanol (70:30) mixture. The residual surfactant may originate from the scouring process and/or from processing oils such as Mulrex.     

The final bleaching of eucalypt kraft pulps with hydrogen peroxide: relationship with industrial ECF bleaching history and cellulose degradation

BACKGROUND: The process of chemical pulp bleaching is based for the most part in chlorine dioxide within elemental chlorine free (ECF) technologies. The use of greener alternatives such as bleaching with hydrogen peroxide (P stage) is not widely used owing to selectivity concerns related to transition metal‐catalyzed decomposition reactions. Even at the final stage where peroxide is recognized to boost brightness and improve the brightness stability of the bleached pulp, cellulose degradation often overcomes these advantages. This paper presents the results of studies intended to optimize final peroxide bleaching performance considering two standard ECF industrial bleaching sequences: the conventional DED and the ECF‐light OQ(PO)D (stages name: D—chlorine dioxide; E—alkaline extraction; O—oxygen; Q—chelation, (PO)—hydrogen peroxide pressurized with oxygen). RESULTS: The addition of sodium diethylenetriaminepentaacetate (DTPA) was the most effective option in terms of DED pulp bleachability and selectivity with hydrogen peroxide, as well as in terms of brightness reversion. As regards the OQ(PO)D pulp, a blend of DTPA and magnesium was the most beneficial in those properties. CONCLUSIONS: The choice of the best hydrogen peroxide stabilizer, among the different tested combinations of magnesium and chelants (EDTA and DTPA) studied, in terms of pulp bleachability, bleaching selectivity and brightness reversion is dependent on the impact of the previous bleaching stages on metallic nature and content. The pulp Mg/(Fe + Cu) ratio was highlighted as a process parameter controlling cellulose degradation in peroxide bleaching. Copyright © 2010 Society of Chemical Industry     

头基结构对表面活性剂在离子液体中表面活性的影响

用表面张力法和红外光谱法(FTIR)研究了3种表面活性剂:十二烷基三甲基溴化铵(DTAB)、十二烷基三乙基溴化铵(DTe AB)和十二烷基三羟乙基溴化铵(DTHAB)在离子液体硝酸乙胺(EAN)中的表面活性以及随温度的变化。结果表明,头基结构的微小变化,对表面活性剂在离子液体中的自组织行为有着重要影响。头基区羟基官能团的存在对表面活性剂的吸附和聚集更是有着明显的促进作用。     

头基结构对表面活性剂在离子液体中表面活性的影响

用表面张力法和红外光谱法(FTIR)研究了3种表面活性剂:十二烷基三甲基溴化铵(DTAB)、十二烷基三乙基溴化铵(DTe AB)和十二烷基三羟乙基溴化铵(DTHAB)在离子液体硝酸乙胺(EAN)中的表面活性以及随温度的变化。结果表明,头基结构的微小变化,对表面活性剂在离子液体中的自组织行为有着重要影响。头基区羟基官能团的存在对表面活性剂的吸附和聚集更是有着明显的促进作用。