Dyeing of pet textile fibers and films in supercritical carbon dioxide

Polyethylene terephthalate (PET) textile fibers were dyed with a disperse dye in the presence of supercritical carbon dioxide at three temperatures of 333.2, 363.2 and 393.2 K and at pressures between 15 and 25MPa. The PET film was also dyed at 393.2 K. It was found that the dye uptake in the fiber increased 2–5 times when a small amount of acetone was added as a cosolvent. The equilibrium dye uptake increased with increasing pressure at all temperatures. At 393.2 K the pressure effect appeared to be much larger. It was explained with the shift of the glass transition temperature of the polymers at high pressures. These results may be useful in designing and developing the pollution-free supercritical dyeing technique, a potential alternative to the conventional dyeing of polyesters that produces a lot of wastewater.     

Theoretical pressure dependency of carbon dioxide solubility under hydrate–liquid water equilibrium

The effect of pressure on carbon dioxide solubility in water is significantly smaller than that of temperature under hydrate–liquid water (H–L_w) equilibrium. As a result, experimental values of carbon dioxide solubility in the water rich liquid phase under H–L_w equilibrium are often inconclusive and in some cases contradictory. This work proposes a theoretical derivation, based on fundamental thermodynamics, of the gas hydrate former solubility dependency on pressure for any binary system under two‐phase equilibrium. The obtained expression is applied to the carbon dioxide–water system under both hydrate–liquid water and vapour–liquid water equilibrium. It is shown that the solubility of carbon dioxide in the water rich liquid phase increases with increasing pressure under H–L_w equilibrium. The predicted trend is then compared to the limited experimental data available in the literature.     

Dyeing nylon-6,6 with some hydrophobic reactive dyes by supercritical processing

Nylon-6,6 fibers, spun from the polyamide (polyhexamethylene diamine adipate), are increasingly required to be dyed with high washing fastness. Nylon-6,6 were dyed with hydrophobic reactive dyes synthesized in our laboratory, using supercritical carbon dioxide as the solvent system. Structures of four hydrophobic reactive dyes and their covalent force with nylon-6,6 fibers were confirmed by FTIR, MS and NMR analysis. Nylon-6,6 were also dyed with C.I. disperse red 2 to compare the result with specimen dyed by hydrophobic reactive yellowish red dye (dye I), which further demonstrated that covalent force was formed between dye-fiber interaction. Dye uptake was moderate to good and the dyed fabrics had very good fastness properties. Results of the latter studies indicated that dyeing nylon-6,6 in supercritical carbon dioxide is feasible.     

改性PET纤维结构和染色性能的研究

自制了两种改性 PET纤维 (MF纤维和 CDP纤维 ) ,并对其染色性能与结构的关系与 PET纤维作了比较。结果表明 ,分散性染料常压沸染时 ,MF纤维和 CDP纤维的半染时间为 9,2 2 min,饱和上染率分别约为 45 % ,40 % ,碱减量处理后 ,碱减量率最大的 CDP纤维的上染率提高了近 1倍 ,高于 MF纤维的上染率 ;而 PET纤维的上染率均远低于 MF和 CDP纤维     

Adsorption thermodynamics and kinetics of disperse dye on poly(p-phenylene benzobisoxazole) fiber pretreated with polyphosphoric acid

Adsorption thermodynamic and kinetic studies of C. I. disperse dye 60 on PBO fiber pretreated with polyphosphoric acid (PPA) were carried out under the conditions of pH 6.0±0.2, initial dye concentration 0.05–1.0 g/L and liquor ratio 2,000: 1. The results showed that the equilibrium adsorption isotherm of the disperse dye on the pretreated PBO fiber was a Langmuir-Nernst mixed Model and the saturated adsorption capacity of the turning point was 1.046 mg/g. The thermodynamic parameters were calculated by the equilibrium adsorption isotherm, such as standard affinity, enthalpy change and entropy change, which indicated that the adsorption of disperse dye on the pretreated PBO fiber was an exothermic process. Based on the thermodynamic and kinetic data, the adsorption of the dye on the pretreated PBO fiber was a kinetics controlled process, and the disperse dye could only diffuse into the surface layer of pretreated PBO fiber. Meanwhile, the adsorption kinetics of disperse dye on pretreated PBO fiber well agreed with a pseudo-first-order kinetic model.     

C．I．分散红60对聚乳酸纤维的上色研究

本文通过研究C.I.分散红60在较低温度下和一定的染浴浓度范围内对聚乳酸纤维的上色率和纤维内的染料浓度讨论了分散染料对聚乳酸纤维染色过程,并进一步探讨了分散染料对聚乳酸纤维的染色动力学.计算了不同温度下C.I.分散红60对聚乳酸纤维的分配系数K、扩散系数DT.结果证明,在分散染料对聚乳酸纤维的上色过程中,上色速率与染液中的染料浓度关系不大,同时染料的上染速率与纤维中染料浓度有关,染料分布与染色时间有关.     

Solubility estimations for Disperse Blue 14 in supercritical carbon dioxide

Supercritical carbon dioxide is an alternative solvent that is considered for dry dyeing processes in the textile industry. The application of this process requires a study to determine the dye solubility in supercritical carbon dioxide. The solubility in supercritical carbon dioxide of a disperse dye at temperatures of 40, 60 and 80 °C and pressures from 100 to 350 bar was evaluated in a previous study. In the work described here, these solubility values have been correlated with fairly good accuracy using a model based on thermodynamic aspects and the use of equations of state. Physical properties and critical parameters of the solid have been estimated using different group contribution methods. The thermodynamic model has been developed by means of a program based on fitting the solid sublimation pressure and binary interaction parameter. The results obtained in the solubility correlation show that the choice of group contribution method is more important than the choice of equation of state.     

Compatibility of a disperse dye mixture in supercritical carbon dioxide dyeing

The compatibility of three disperse dyes, CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, which are commonly used as a trichromatic combination for conventional dyeing, was studied in supercritical carbon dioxide dyeing. Both the dyeing rate and the build‐up of the selected dyes were measured. Experimental results showed that they were quite compatible. The dyeings of a binary combination (CI Disperse Orange 30 and CI Disperse Blue 79, mass ratio 1:1) and a ternary combination (CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, mass ratio 1:1:1) at different dye concentrations showed an on‐tone uptake and presented the same metric hue angles. This proved that the selected dyes could form a useful trichromatic combination in supercritical carbon dioxide dyeing. Furthermore, the uptake and exhaustion of the single dyes in supercritical carbon dioxide dyeing were similar to those in aqueous dyeing, implying that the dyeing media play only a minor role in the dyeing of polyester fibres with disperse dyes.     

丙烷-乙醇-水体系相平衡研究

提出了改进的DDLC-MH(81)状态方程,用于丙烷-乙醇-水体系二元汽液平衡数据的关联计算,其模型参数与温度有良好的线性关系.并用汽相循环法测定了该体系在不同温度下的二元及三元VLE数据,结果与模型的推算值取得良好的一致.并用模型预测了超临界丙烷条件下的三元相平衡数据.结果表明,在液相乙醇浓度高于0.2的情况下,超临界丙烷比超临界二氧化碳有更高的乙醇溶解度和选择性.     

Modified Soave-Redlich-Kwong equations of state applied to mixtures containing supercritical carbon dioxide

The well-known equation of state Soave-Redlich-Kwong and two of its modifications are applied to describe vapor-liquid equilibrium in binary asymmetric mixtures, which contain supercritical carbon dioxide and a heavy component. Several mixing rules including the classical van der Waals mixing rules with one and two interaction parameters, non-quadratic mixing rules, and the used of a Gibbs free energy model, are used with these equations. Seven mixtures containing supercritical carbon dioxide are considered in the study. The experimental data were obtained from literature sources and the adjustable parameters were found by minimizing the errors between predicted and experimental data of the concentration of the solute in the liquid phase. The work allows concluding on the advantages, disadvantages and expected accuracy of these equations of state and mixing rules for correlating vaporliquid equilibrium data in asymmetric systems as those studied.     

Incorporation of disperse dye in N,N-dimethylacrylamide modified poly(ethylene terephthalate) fibers with supercritical CO2

The effects of modifying agents and dyeing conditions of dispersed dyes for PET films and fibers has been thoroughly studied. This research reports on the dye incorporation process of non-modified and N,N-dimethylacrylamide modified PET fibers with supercritical CO₂. Spectral analysis in the infrared region to the modified PET fibers showed peaks of the modifier, but the thermal stability of the modified fiber did not show variation when compared with the non-modified. The amount of disperse dye incorporated in the PET fibers was determined by UV–Vis spectroscopy at 579 nm through the dye extraction using N,N-dimethylformamide. A 2⁴ factorial design was realized with the purpose to study the influence of variables in the dye incorporation process as well as their interaction effects. The pre-treatment of the PET fibers with N,N-dimethylacrylamide increases the amount of incorporated dye 3.8 times, in average. The main effect on the dye incorporation was the dyeing time for the modified fibers, but for the non-modified fibers, the pressure and the temperature presented analogous main effect     

Solubility of a reactive disperse dye in supercritical carbon dioxide

The solubility of a reactive disperse dye, which was modified from CI Disperse Red 17 with a derivative of 1,3,5‐trichloro‐2,4,6‐triazine as the reactive group, was investigated in supercritical carbon dioxide fluid by employing a batch system equipped with an online spectrophotometer. The investigations were carried out at pressures of 7.5–25.0 MPa, temperatures of 333.15–413.15 K and an equilibrium contact time of 120 min. As revealed from the experimental results, the solubility of the reactive disperse dye increased with pressure in different isotherms, and decreased with temperature. Furthermore, the experimental solubility data were correlated successfully with semi‐empirical models – Chrastil and Del Valle–Aguilera equations, respectively – at various temperatures and pressures.     

Modelling of polymerization kinetics and molar mass development in the nitroxide-mediated polymerization (NMP) of styrene in supercritical carbon dioxide using the PC-SAFT equation of state

A mathematical model for polymerization kinetics and molar mass development in the nitroxide-mediated polymerization (NMP) of vinyl monomers in supercritical carbon dioxide (scCO₂) has been developed. The method of moments is used for molar mass development. The perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state is used to estimate the number of stable phases present at equilibrium in the reaction mixture, critical number average chain length at which polymer particles are formed, and monomer concentration in each phase. Pure and binary PC-SAFT interaction parameters are estimated from liquid–liquid equilibrium (LLE) and liquid–vapour equilibrium (LVE) experimental data at 60 to 129°C. The effect of pressure on monomer conversion and molar mass development in the polymerization of styrene (Sty) using benzoyl peroxide (BPO) and 2,2,6,6-Tetramethylpiperidinyl-1-oxyl (TEMPO) at 120°C and 300–500 bar is studied. It was observed that increasing pressure increases polymerization rate without significantly affecting molar mass development.     

Describing the sorption characteristics of a ternary system of benzene (1) and alcohol (2) in a nonporous polymer membrane (3) by the Flory–Huggins model

The Flory–Huggins equation was used to describe results of total and preferential sorption measurements for the binary liquid mixture of benzene (1) and alcohol (2) in one of two nonporous polymer membranes (3), low‐density polyethylene (LDPE) and Nafion membrane. The concentration dependence of binary and ternary interaction parameters was determined. The interaction parameters for the benzene – methanol binary mixture were obtained from binary vapor‐liquid equilibrium data in the literature to decrease the number of adjusted parameters. The results show that use of a ternary interaction parameter is necessary. Data treatment was performed assuming either no crystallinity or an average crystallinity typical for the studied membranes. Subsequently, the limiting activity coefficients of solutes in LDPE were calculated from the values of the interaction parameters and their values compared to values of the limiting activity coefficients of benzene and methanol in hypothetical liquid alkane with the same density as LDPE obtained by the UNIFAC method. POLYM. ENG. SCI., 55:1187–1195, 2015. © 2014 Society of Plastics Engineers     

分散染料在涤/锦双组分纤维上色差的色度学分析

将涤 /锦复合丝分离成单一组分的超细涤纶和锦纶。用常用的分散染料同浴染色后 ,测定了各染色样品的颜色三刺激值 ,并经过色度学计算。实验分析表明 ,分散染料对锦纶染色物的反射光主波长值较相应涤纶染色物向长波方向移动 ;蒽醌类分散染料在锦纶上的得色量较小 ,彩度较低 ;而偶氮类分散染料对涤 /锦染色的总色差较小 ,较适合于涤 /锦复合丝的染色。     

Copolyester studies. IV. Dyeing behavior of drawn and undrawn fibers derived from tetramethylene terephthalate–tetramethylene sebacate copolymers

Drawn and undrawn fibers of tetramethylene terephthalate–tetramethylene sebacate copolymers, containing up to 20 mol % of the latter, have been dyed in an infinite dyebath with a disperse dye. The dyeing process has been interpreted in terms of the equilibrium dye absorption, the half-time of dyeing, and the diffusion coefficient. Increasing sebacate content has been found to have a marked effect on the rate and level of dye uptake. Deviations from Fickian behavior have been observed for the drawn fiber and related to presence of voids.     

Using the solubility parameter to explain disperse dye sorption on polylactide

The solubility parameters of polylactide (PLA), poly(ethylene terephthalate) (PET), and various disperse dyes calculated according to the group contribution method were used to explain the low sorption of some disperse dyes on PLA but the high sorption of the same dyes on PET. It was found that the dyes with high sorption on PLA tended to have solubility parameters near that of PLA, which has a lower solubility parameter than that of PET. It was also found that the solubility parameter, which was calculated based on cohesive energy and molar volume at 25°C, was more appropriate for explaining dyeings at lower temperature, 100 and 110°C, than those at higher temperature, 130°C. Based on the finding that dyes with solubility parameters near that of PLA tend to have high sorption on PLA, general structures for disperse dye that may have high sorption on PLA were proposed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 416–422, 2005     

Correlation of solubility data of azo disperse dyes with the dye uptake of poly(ethylene terephthalate) fibres in supercritical carbon dioxide

Solubility data of disperse azo dyes in supercritical carbon dioxide are presented for dyeings of poly(ethylene terephthalate) fibres with CI Disperse Red 167:1, carried out at 200–300 bar and 80–120 °C, with varying amounts of adulterants. The same dyeings were also carried out in water for comparison. Scanning electron micrographs were taken of the dyes which show a growth of dye crystals during treatment in supercritical carbon dioxide. The paper reports that at 120 °C, melting of the pure dye CI Disperse Red 167:1 is observed. The presence of adulterants in the dye formulations help prevent agglomeration by acting as spacers between the dye molecules. Dyeings of PETP carried out under conditions of the highest solubility of the dye in supercritical carbon dioxide do not necessarily result in a very high dye uptake. This was shown by pressure- and temperature-dependent dyeing experiments of PETP in supercritical carbon dioxide.     

分散红343、分散蓝366及其混合物在超临界CO_2中的溶解度测定和关联

为超临界CO2染色工艺提供必要的基础数据,采用静态循环法在343.2～383.2 K,12～28 Mpa温度压力范围内,测定了分散红343和分散蓝366及其混合物在超临界CO2中的溶解度.实验结果表明,二元体系(分散红343+CO2,分散蓝366+CO2)和三元体系(分散红343+分散蓝366+CO2)中染料的溶解度均随温度和压力的升高而增大;染料分子的极性对其在超临界CO2中的溶解度影响较大;三元体系中两种染料的溶解存在"共溶剂效应"和竞争溶解作用;两种染料在二元和三元体系中的溶解度实验数据用Chrastil方程关联,结果较好.     

Comparison of disperse dye exhaustion,color yield,and colorfastness between polylactide and poly(ethylene terephthalate)

Ten popular disperse dyes with different energy levels and chemical constitutions were used to compare their exhaustion, color yield, and colorfastness on polylactide (PLA) and poly(ethylene terephthalate) (PET). Only two out of the 10 dyes had exhaustions higher than 80% on PLA at 2% owf. Five out of the 10 dyes had exhaustions less than 50%. All 10 dyes had more than 90% exhaustion on PET, whereas six of them had exhaustions of 98% or higher. There was no obvious pattern as for which energy level or which structure class provided dye exhaustion better than that of others. Although PLA had lower disperse dye exhaustion than that of PET, it had higher color yield. Based on the 10 dyes examined, the color yield of PLA was about 30% higher than that of PET. This means that even with low dye uptake, PLA could have a similar apparent shade depth as that of PET if the same dyeing conditions are applied. Our study supported that the lower reflectance, or reflectivity, of PLA contributes to the higher color yield of PLA than that of PET. A quantitative relation between the shade depth of PLA and PET based on their dye sorption was developed. Disperse dyes examined had lower washing and crocking fastness on PLA than on PET. The differences in class were about 0.5 to 1.0. If the comparison was based on the same dye uptake, the differences might be larger. The differences in light fastness between the two fibers were smaller than that in washing and crocking fastnesses. The light fastness of disperse dyes on PLA is expected to be even better if the comparison is based on the same dye uptake on both fibers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3285–3290, 2003