Effect of Montmorillonite Clay Nanoparticles on the Properties of Polypropylene Fibres

Polypropylene and nanocomposite polypropylene fibres were successfully prepared via a melt spinning process. The prepared fibres were characterized by TGA and SEM. The results obtained show that the addition of MMT clay in the fibre induces a higher thermal stability. Water absorption and mechanical properties of the fibres were improved by the introduction of MMT clay nanoparticles in the fibre. Dyeing studies underlined the effect of the clay on the dyeability of the fibres which improved the accessibility of the fibre for both acid and disperse dyes. Moreover, it was observed, that polypropylene and nanocomposites polypropylene fibres were satisfactorily dyed with disperse dyes more than with acid dyes.     

Adsorption behaviour of azo disperse dyes on polyurethane fibre

Adsorption isotherms of disperse dyes were measured and the surfaces of dyed polyurethane, cellulose diacetate and polylactic acid fibres were observed using a scanning electron microscope and compared. Obvious crystal growth of the dyes occurred on the surface of the polyurethane fibres. The maximum dye uptake on polyurethane fibres and the degree of crystal growth varied greatly with the dye type. Factors such as the dye affinity for the fibre, crystallisation properties and dye solubility in the dyebath affect the sorbed state of the dye on the fibre surface. A mechanism is proposed for crystal formation on the fibre surface during dyeing of polyurethane fibre with disperse dyes.     

The effect of heat setting on the dyeability of differentially dyeable polyester fibres

Apparent diffusion coefficients of two disperse dyes for so-called easily dyeable/cationic-dyeable polyester (ED-CDPET) and cationic-dyeable polyester (CDPET) fibres of identical linear density and sulphonic acid group content have been calculated. It was found that the diffusion coefficients of dyes for ED-CDPET were far greater than those of dyes for CDPET. The dyeability at the boil without carrier, using disperse and cationic dyes on various ED-CDPET and CDPET fibres, has been studied. ED-CDPET was found to have higher dyeability at all levels of heat setting (irrespective of the dye used). The finest ED-CDPET fibres showed maximum dye uptake as a result of increased surface area. Heat setting in the taut condition reduced dye uptake.     

Relationship between the solubility of disperse dyes and the equilibrium dye adsorption in supercritical fluid dyeing

In order to understand the dyeing behaviour of synthetic fibres in supercritical carbon dioxide, the solubility of some disperse dyes in supercritical fluid, as well as the rate of dyeing and the equilibrium adsorption of these dyes, have been studied. Dye solubility was measured by a dynamic analytic method at a range of pressure (7.5–25 MPa) and temperature (50–145 °C). The apparent rate of dyeing was measured and the dyeing isotherm was obtained by plotting the equilibrium dye adsorption against the equilibrium dyebath concentration. Linear isotherms were obtained when poly(ethylene terephthalate) samples were dyed with the disperse dyes. The mechanism of dyeing using supercritical carbon dioxide was discussed by considering the solubility, the dyeing rate and the dyeing isotherm.     

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.     

Structural, Physicomechanical, and Sorption Properties of Ternary Acrylonitrile Copolymer Fibres

When itaconic acid (IA) is replaced by vinylcaprolactam (VCL) in ternary AN:MA:IA (acrylonitrile:methyl acrylate:itaconic acid) copolymers, fibres similar in structure to industrial Nitron fibre are obtained, and they have a higher capacity for orientation the larger the amount of VCL added to the copolymer. The fibres obtained have higher physicomechanical properties and higher hydrophilicity and dyeability with disperse dyes than Nitron fibres. The values of the diffusion coefficient of equilibrium-sorbed dye, activation energy, and some thermodynamic properties are calculated. An increase in the VCL content in the copolymer and an increase in the temperature cause an increase in the degree of fixation of the disperse dye in the fibre. In ordinary dyeing conditions, a high residual dye content in the fibre can be attained.     

分散染料在共混纤维上的分布状态研究

用少量的烯烃类高聚物加入到聚丙烯中,制成分散染料可染丙纶,对共混丙纶的结构和分散染料染色后染料分子在纤维上的状态与反射光谱的关系进行了研究.结果表明,共混纤维内部存在大量的相界面,分散染料部分缔合在这些界面上,从而引起反射光谱的变化.染料分子在纤维上的状态直接影响被染织物的K/S值和艳度.     

Organoclays assisted vat and disperse dyeing of poly(ethylene terephthalate) nanocomposite fabrics via melt spinning

Polyethylene terephthalate nanocomposites containing six modified montmorillonite nanoclays were prepared by a melt compounding technique. The effect of intercalated compounds of montmorillonite on textile mechanical properties of resultant polyethylene terephthalate nanocomposite fabrics was investigated. Winding was not possible, when the polymers were first compounded with the desired amount of montmorillonite and then spun, as filament breakage occurred. Spinable polymer were only obtained by mixing polyethylene terephthalate master batches with 4 wt% montmorillonite, which contained tallow intercalating compound with pure untreated polyethylene terephthalate to a montmorillonite content of 0.5 wt%, thus decreasing the concentration of thermally degraded polymer chains. After spinning the fibres were drawn and knitted into fabric samples for further testing. The prepared polyethylene terephthalate nanocomposite fabrics using montmorillonite exhibited higher colour strength using vat and disperse dyes compared with those of the reference fabrics made from fibres spun without montmorillonite clay content and regular fabrics. The carbocyclic‐based vat dyes have higher colour strength values on polyethylene terephthalate nanocomposite fabrics if compared with heterocyclic‐based vat dyes. The colour fastness ratings for both vat and disperse dyeings secured very good to excellent washing and perspiration fastness on polyethylene terephthalate nanocomposite fabrics. All dyed fabrics showed excellent light fastness using vat and disperse dyes. The preparation of polyethylene terephthalate nanocomposite fabrics with improved textile mechanical and vat dyeing properties needs further investigations.     

Dye Fixation Using Radio—frequency Heating

Radio-frequency (r.f.) heating has been used to achieve the fixation of acid dyes on nylon fibres. This permitted rapid heating to the fixation temperature, and some enhancement in the degree of dye penetration was observed. Success was also obtained in fixing disperse dyes on polyester and reactive dyes on cotton using r. f. techniques. The experiments clearly demonstrate that r.f. heating offers a versatile method for enhancing dye fixation.     

Biological treatment of effluent containing textile dyes

Colour removal of textile dyes from effluent was evaluated using a laboratory 'upflow anaerobic sludge blanket' reactor. Several commercial dyes were selected to study the effect of dye structure on colour removal. The anaerobic reactor was fed with glucose, an easily biodegradable organic matter and selected individual dyes. Results show that some of the dyes are readily reduced under anaerobic conditions even at a high concentration of 700 mg/l. The average removal efficiency for acid dyes using this method was between 80 and 90% and that observed for the direct dye used was 81%. Laboratory experiments using the anaerobic reactor with disperse dyes, such as an anthraquinonebased dye, were unsuccessful even at low concentrations of 35 mg/l. Additional experiments were conducted to evaluate the toxicity of a selected disperse dye to an anaerobic environment. Results indicate that the purified dye is more toxic to the biomass than the commercial one.     

Dye sorption characters of gamma irradiated foamed ethylene propylene diene monomer (EPDM) rubber/clay composites

Composites based on gamma irradiated ethylene propylene diene monomer rubber in foam structure, loaded with different types of clays were used as adsorbents for different classes of dyestuffs (basic, acid, reactive and disperse) from aqueous solutions. The clays under investigation were Aswan clay (ASC) and sodium montmorillonite (Na-MMT). The effect of adsorbent composition, irradiation dose, pH and contact time on dye sorption was studied. It was found that the rubber composites loaded by Na-MMT gave maximum adsorption of the basic dye (～42%) in aqueous solution, while the rubber composites loaded by AS clay gave maximum adsorption (～28%) of the acidic dye. On the other hand, both type of clays did not show no affinity toward reactive and disperse dyes. The efficiency of dye removal was found to increase with increasing the pH and contact time. It was also observed that the irradiation dose (50 kGy) was the optimum dose for the removal of dyes for all rubber composites.     

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.     

Dyeing behavior of polypropylene blend fiber. II. Ionic exchange mechanism of dyeing

The dyeability of polypropylene fibres modified by two nitrogen polymeric additives containing dye sites of different basicity and accessibility was investigated using an acid dye. The thermodynamic and kinetic parameters of dyeing under infinite bath conditions were determined for four aqueous dye solutions. It is postulated that ionized molecules of acid dyes diffuse within the fiber after activation of a dye site by a suitable agent. In addition, color yield and color fastness of various dyes have also been studied. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 543–550, 1997     

Dyeing of poly(lactic acid) fibres with synthesised novel heterocyclic disazo disperse dyes

Poly(lactic acid) (PLA) is the first melt‐processable, renewable, sustainable and biodegradable natural‐based synthetic fibre. It has a broad range of uses and combines ecological advantages with outstanding performance in textiles. PLA fibre, as an aliphatic polyester, can be dyed with disperse dyes. Apart from the limited number of commercial disperse dyes, disperse dye exhaustion on PLA is generally lower than that on  poly(ethylene terephthalate) (PET). In this study, new heterocyclic disazo disperse dyes, substituted with methyl, nitro and chloro groups at their ortho‐, meta‐ and para‐ positions, synthesised in our previous study, were applied to PLA and PET fibres to examine their dyeing performance, and colour fastness and dye exhaustion properties. Different shades of yellow, orange, reddish brown and brown were obtained. Most of the synthesised novel heterocyclic disazo disperse dyes exhibited good build‐up properties with high K/S levels on both fibres. Para‐ bonding substituent provided higher K/S values than meta‐ and ortho‐ positions for –NO₂ and –Cl substituents for both fibres. Overall, the most synthesised novel heterocyclic disazo disperse dyes in this study exhibited good build‐up properties with high K/S, exhaustion and wet fastness levels on both PLA and PET fibres.      

Synthesis,spectral and dyeing properties of phenylazopyrazolone‐containing acylamide disperse dyes designed for poly(lactic acid)

A series of phenylazopyrazolone disperse dyes containing an acylamide moiety were synthesised from carboxyl‐containing acid dyes via chlorination and amidation with different sorts of amines. The structures of these new dyes were confirmed by Fourier Transform–infrared, proton nuclear magnetic resonance, mass spectroscopy and elemental analysis. Their solvatochromic properties in different solvents were also investigated and the absorbance spectra of the acylamide dyes in solution exhibited a red shift when dissolved in dimethylformamide, compared with acetone. Their dyeing behaviour, including dye sorption, colour build‐up and colour fastness properties on poly(lactic acid) fibres, was also determined, whereupon it was found that the tertiary acylamide dyes simultaneously exhibited high dye sorption and satisfactory colour build‐up and fastness properties on the poly(lactic acid) fabric.     

The dyeing and colour characteristics of alkali–treated polyester fibres dyed with disperse dyes

Alkali–treated and untreated polyester fabrics were dyed for up to 6 h at 100°C with a series of six disperse dyes of different chemical structures. The alkali–treated polyester samples adsorbed more dye and were dyed to deeper depths of shade and slightly different shades than was the untreated polyester. The greatest differences were observed for the alkali–treated polyester with the most outer surface or skin removed. Dye structure and molecular size also affected the amount of dye adsorbed on the fibres, but did not delineate the nature of differences between skin and core morphology. This study shows that significant differences exist between the molecular structure of the skin and core of melt–spun polyester fibres.     

可染型丙纶的研究

采用高聚物共混改性的方法,研制出可染聚丙烯树脂,对其流变性、可纺性及其纤维的染色性进行了研究。结果表明,共混丙纶具有良好的分散染料可染性,而且各项牢度良好。     

Nylon 6.6 dyeing behaviour for fibres of different levels of fineness

Nylon 6.6 microfibres are now commonly produced. During dyeing, these microfibres appear to be more accessible to both acid and disperse dyes, than thicker fibres. This phenomenon is enhanced with the use of small dye molecules. In this paper, the mechanism of fixation of disperse dyes is shown to be due to adsorption as well as dissolution. In nylon 6.6 the fraction of disperse dye adsorbed is greater than the fraction dissolved. The conditions of drawing are supposed to create imperfections in the amorphous phase. The amount of microvoids created in microfibres favours the adsorption phenomena of disperse dyes via polar bonds.     

Polypropylene alloy filaments dyeable with disperse dyes

Polypropylene fibres which can be conventionally dyeable using disperse dyes have been prepared by alloying with nylon 6 and a polypropylene grafted maleic anhydride compatibiliser during extrusion. The dyeing performance of fibres containing various amounts of these components has been assessed.     

The Dyeing of Unmodified Polypropylene with Disperse Dyes

The behaviour on unmodified polypropylene fibre and film of two commercial disperse dyes and Dimethyl Yellow has been examined. The results indicate that disperse dyes capable of dyeing polypropylene fibre have high diffusion coefficients and low saturation values. Linear adsorption isotherms were obtained with Dimethyl Yellow. The behaviour of polypropylene fibre towards disperse dyes in general is discussed.