Metal-complex Dyes for Wool and Nylon — 1930 to date

An introduction outlining the scope and limitations of this paper is followed by a brief explanation of the essential structural features of metal-complex dyes. The earliest metal-complex dyes were produced directly within the fibre material by reacting a metallisable dye with a chromium compound in situ. The first chromium complex dyes prepared in substance, were the chromium complexes containing sulpho-groups, synthesised by R Bohn of BASF, in 1912, the application of which was first made possible after the discovery by Ciba of a satisfactory dyeing process based on the use of a dyebath made strongly acid with sulphuric acid. These two classes of dye dominated the dyeing industry into the 1950s. At that time 1:2 metal-complex dyes without sulphonic acid groups but containing nonionic substituents as solubilising groups were introduced. These complexes were applicable from neutral to weakly acid dyebaths, which minimised the damage to the fibres. These dyeings were characterised by high fastness to light and wet treatments. Later, for commercial reasons, sulphonic acid groups were again introduced into the dye molecule to increase their hydrophilic properties. These dyes also have become well established as a result of the introduction of new dyeing methods and the development of dyeing auxiliaries designed to promote level dyeing. In addition to these types of metal-complex dyes, further metal-complex dyes selected from the extensive patent literature of the last 50 years because of their interesting structure are described.     

Preparation and properties of water‐soluble polyester surfactants. II. Preparation and surface activity of silicone‐modified polyester surfactants

We prepared a novel series of water‐soluble silicone‐modified polyesters [poly(ethylene glycol) (PEG)–silicone polyesters] by reacting organopolysiloxane with a hydroxy‐terminated polyester. The polyesters were obtained by the polymerization of maleic anhydride and PEGs (molecular weights = 2000, 4000, 6000, 8000, and 10000). These water‐soluble PEG–silicone polyesters can be used as auxiliaries in dyeing process because they exhibit good surface activities such as surface tension, low foaming, and wetting power. The presence of these surfactants also retarded the rate of nylon dyeing with acid dyes. The retarding effect and low‐foaming property of these novel PEG–silicone polyesters make it possible for these surfactants to be used as leveling agents for modern nylon dyeing with acid dyes. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3005–3012, 2002     

Synthesis and spectral properties of azohydroxypyridone disperse dyes containing a fluorosulphonyl group

A series of azohydroxypyridone disperse dyes containing fluorosulphonyl groups have been synthesised and their spectral properties were investigated. Azohydroxypyridone dyes, containing a nitro group instead of a fluorosulphonyl group para to the azo group in the diazo component, were also synthesised in order to compare spectral properties. The fluorosulphonyl substituted derivatives absorb maximally at shorter wavelengths and are tinctorially weaker than the nitroarylazopyridone dyes, although the former dyes have higher molar extinction coefficients. Also, the synthesised dyes exhibit positive solvatochromism so that the absorption bands of the dyes move toward longer wavelengths as the polarity of the solvent increases. Molecular computational methods provided reasonable predictions in the direction of solvatochromism for the dyes prepared.     

Preparation of thermally stable dyes derived from diketopyrrolopyrrole pigment by polymerisation with polyisocyanate binder

Four thermally stable and solvent soluble dyes were prepared from diketopyrrolopyrrole pigment via an N‐alkylation reaction. To improve the thermal stability of the dyes, a hydroxyl functional group that could react with blocked polyisocyanates was introduced into the dyes. The prepared dyes had absorption maxima near 500 nm, and the chromaticity diagrams of all synthesised dyes exhibited smaller x and y values than those of CI Pigment Red 254, indicating that the colour of the synthesised dyes was close to an orange shade. The dyes reacting with blocked polyisocyanates showed extremely high thermal stability compared with analogous dyes not reacting with polyisocyanates.     

Novel DCPD-modified polyester containing epoxy groups: thermal,viscoelastic, and mechanical properties of their wood flour filled copolymers

In this article, the synthesis of novel DCPD-modified polyesters containing epoxy groups and their possible utilization as polar matrices for wood flour filled copolymers have been studied. The novel DCPD-modified polyester containing epoxy groups was prepared during three-step process. First, the addition reaction of maleic acid to DCPD norbonenyl double bond has been performed. Then, the polyesterification of acidic ester of DCPD, cyclohex-4-ene dicarboxylic anhydride, and ethylene glycol (ethane-1,2-diol, EG) or neopentyl glycol (2,2-dimethyl-1,3-propanediol, NP) in the presence of catalyst was carried out using melt condensation technique. Finally, the oxidation process of prepared DCPD-modified polyesters led to obtain DCPD-modified polyesters containing epoxy groups. The structural characterization of prepared DCPD-modified polyesters containing epoxy functionality has been carried out using FTIR and HNMR spectroscopic methods. The thermal, viscoelastic, and mechanical properties of their unfilled and wood flour filled copolymers have been studied by DSC, DMA, TGA analyses, three-point bending test, and Brinell’s hardness. The performed investigations indicated that novel DCPD-modified polyesters containing epoxy groups can be successfully applied as polar matrices for preparation wood flour filled copolymers due to their “compatibility” with hydrophilic wood flour surface which resulted with stronger interactions between wood and polymer surface and thus producing copolymers which were characterized by improved thermo-mechanical properties compared to unfilled copolymers.     

Polymers from 2,5-difluoroterephthalic acid. I. Polyesters

A new synthetic route to 2,5-difluoroterephthalic acid (DFTA) was devised and from this several new series of polymers were prepared by polycondensation. This inaugural paper will cover polyesters while subsequent papers will report on keto polyethers, polyamides and other backbones derived from DFTA. DFTA was synthesized from 2,5-difluorotoluene, which was acylated and subsequently converted to the diacid by a several step oxidation process. Various polyesters were prepared by reacting it with numerous bisphenols and diols by solution condensation to give a series of difluoroterephthalate polyesters with viscosities ranging from 0.16 to 0.61 dl/g. Thermogravimetric analyses showed that the polyesters had thermal stabilities up to 480°C in nitrogen; melting temperatures ranged from 127 to 318°C.     

New perylene dyes,derivatives of 1,6,7,12‐tetrachloroperylene‐3,4,9,10‐tetracarboxylic acid: synthesis and application

New dyes – aliphatic esters of 1,6,7,12‐tetrachloroperylene‐3,4,9,10‐tetracarboxylic acid – were prepared as potential fluorescent light‐stable colorants for high‐visibility safety wear. The structure of the 15 perylenes was confirmed by ¹H and ¹³C nuclear magnetic resonance spectroscopy and mass spectrometry, and their spectroscopic and physicochemical properties were determined. An attempt was made to apply the synthesised products as disperse dyes in the coloration of polyester as well as in the mass coloration of polystyrene and poly(methyl methacrylate). The light, wash, and rubbing fastness of the dyeings were determined, and chromaticity coordinates of selected samples were measured and discussed.     

Studies on cyanine dyes. III. Synthesis of 2-styryl-5-cyanonaphthoxazole cyanine dyes

New types of styryl cyanine dyes (V) containing two different heterocyclic nuclei were prepared through the reaction of 5-cyanonaphth[1,2-]-oxazole-2-carboxaldehyde (IV) with α-picoline and quinaldine ethiodides. Other styryl bases (III) were also obtained as reaction products between 2-methyl-5-cyanonaphth[1,2-d]oxazole (I) and aromatic aldehydes in the presence of anhydrous zinc chloride. Structural configurations of the synthesised compounds were identified by u.v. and i.r. spectra determination.     

High fastness heterocyclic azo disperse dyes bearing ester functions

Blue monoazo disperse dyes bearing carboxylic acid ester functions have been synthesised from thiophene diazo components in the search for colorants of high fastness and reduced environmental impact. The colour properties of the dyes in solution and on polyester, as well as the fastness of the dyes when applied to polyester, are examined and rationalised in terms of dye structure.     

Synthesis of temporarily solubilised azo disperse dyes containing a β‐sulphatoethylsulphonyl group and dispersant‐free dyeing of polyethylene terephthalate fabric

Disperse dyes containing a β‐sulphatoethylsulphonyl group have temporary solubility and can be applied for dispersant‐free dyeing of hydrophobic fibre. Six novel temporarily solubilised azo disperse dyes having a β‐sulphatoethylsulphonyl group in their structures were synthesised, and their dyeing properties on polyester were investigated. As a dye intermediate, a diazo component having dibromo groups was prepared, and 4‐diethylamino‐4′‐(2‐sulphatoethylsulphonyl‐4,6‐dibromo)azobenzene dyes were prepared by a diazo‐coupling reaction. Then, the dyes containing dicyano groups were prepared by cyanation of corresponding dyes with dibromo groups. The absorption maxima of the dyes were affected by the substituents in the diazo and coupling component rings and varied from 434 to 616 nm in dimethylformamide. Polyethylene terephthalate woven fabric could be dyed with the synthesised temporarily solubilised dyes without using any dispersants. Dyebath pH affected the K/S value at maximum absorption as well as percentage exhaustion on polyethylene terephthalate fabric, and the optimum pH was 5. The dyes gave brownish orange, red, purple, and greenish blue hues on polyethylene terephthalate fabrics, and colour build‐up was good. Wash fastness was good to excellent, rubbing fastness was moderate to excellent, and light fastness was poor to moderate.     

Spectral characterisation and computational studies of some novel phenylazoindol‐2‐one dyes

A series of novel phenylazo disperse dyes were prepared by coupling selected diazotised 3‐ or 4‐anilines with indol‐2‐one. The structures of the synthesised dyes were determined by spectroscopic and analytical methods. Solvent effects on the ultraviolet–visible absorption spectra of these novel dyes were studied. The colour of the dyes was evaluated with respect to the substituent therein. Acid and base effects on the visible absorption maxima of the dyes were also reported. The tautomerism of 3‐(phenyldiazenyl)indol‐2‐one was modelled by density functional theory at the B3LYP level. The ultraviolet–visible absorption spectra for the tautomers were reproduced with the time‐dependent density functional theory and semi‐empirical Zerner’s intermediate neglect of differential overlap/spectroscopic (ZINDO/S) method. The predominance of the keto–hydrazone tautomer was confirmed experimentally and theoretically.     

The biocidal properties of anthraquininoid dyes

A modified minimum inhibitory concentration test method was employed to determine the antimicrobial properties against both Gram-positive and Gram-negative bacteria of two series of cationic anthraquininoid dyes. The antimicrobial strength of the colorants increased with increasing carbon chain length up to C16; the activities of the colorants were improved by the use of elevated temperature as well as either high or low pH. However, the colorants were deactivated in the presence of both anionic surfactants and divalent cations.     

Encapsulation of colorants by natural polymers for food applications

Product appearance is an important factor for consumers when determining the quality of a product, and colour is one of the most important factors which contribute to product appearance. Currently, the safety and consumer acceptance of some colorants used in food products, such as titanium dioxide and some synthetic colorants, are under discussion. Therefore, new ways to use natural colorants as alternatives to these suspect colorants for future applications are being investigated. A promising method for increasing the applicability of the often sensitive natural colorants is the encapsulation of these colorants in colloidal particles by natural polymers such as carbohydrates, lipids and proteins. In recent years, micro‐ and nano‐encapsulation have increasingly been used for various purposes concerning several food properties such as colour, flavour and micronutrient content. This technique results in improved stability for the often sensitive natural colorants and presents the possibility of entrapping water‐insoluble colorants for improved use in an aqueous system. This paper reviews the main methods that are used for encapsulation by natural polymers, discusses the different types thereof that are used for encapsulation of colorants, and provides a short overview of natural colorants successfully encapsulated in these natural polymers.     

Modification of unsaturated polyesters using polyethylene glycol

Abstract

The fracture toughness and impact resistance of rigid unsaturated polyesters can be modified by various physical and chemical methods. In this study, flexible unsaturated polyesters were prepared by condensation polymerisation of maleic anhydride, phthalic anhydride and propylene glycol in the presence of polyethylene glycol. By this method, copolymers of unsaturated polyesters with polyethylene glycols of different molecular weights were prepared. A two stage process was used for the synthesis, which resulted in segmental structures containing alternating rigid cross-linked segments and linear soft segments displaced regularly in the polymer chain. Properties such as tensile strength, tensile modulus, elongation at break, toughness, impact strength, surface hardness, abrasion resistance and water absorption were tested after the resin was cured in appropriate moulds and compared with those of the control resin. Polyethylene glycols of lower molecular weight (～ 200) impart flexibility to the polyester chains and increase fracture toughness and impact resistance of rigid unsaturated polyester without seriously affecting other properties. Glass reinforced specimens prepared using the modified resin also show improved toughness and elongation at break.     

Synthesis and characterization of some novel unsaturated polyester resins containing amide groups

Summary An ethylenically dibasic acid amide was prepared by reacting anthranilic acid with maleic anhydride and characterized by various methods. The unsaturated dibasic acid amide was used for preparing three novel unsaturated polyesters with ethylene glycol (EG), diethylene glycol (DG) and tetraethylene glycol (TG), respectively. The molecular weights of the prepared polyesters were determined by the end group analysis. These polyesters were diluted with styrene / acrylonitrile (AN) mixture to prepare curable resins with inhibited premature gelation. The effect of the structure of the resins on their curing behavior and mechanical properties has been investigated.     

Design and application of a multifunctional reactive dye capable of high fixation efficiency on cellulose

A polyfunctional reactive dye containing two dichloro- s -triazine residues linked through aliphatic amino groups via a third triazine system to the chromophoric residue has been prepared. The dye was synthesised stepwise from a specially synthesised 2,4-dichloro- s -triazine dyes. The first step is the reaction of both carbon–chlorine sites in the 'parent' dye with 2 mol ethylenediamine under selected conditions of pH and temperature; these conditions ensure that only one of the amino groups in the ethylenediamine will react to give the bis-2,4-aminoethyleneaminotriazine dye. The second step is the condensation of 2 mol cyanuric chloride with the two pendant primary amino groups. The alkylamino-linked dichloro- s -triazine dyes show very different dyeing properties when compared with those shown by the parent dichloro- s -triazine dye, which has the reactive group linked directly into the aromatic chromophore; in particular, the new dyes have high fixation efficiencies when dyed on cotton at 50 °C and the dye–fibre bond stability to boiling acidic conditions is very good.     

Crosslinking nucleophilic dyes on wool

Nucleophilic amino-alkyl dyes have been synthesised by the simple expedient of reacting existing reactive dyes with ethylene diamine. These dyes when applied to wool behave as acid dyes, although there is a small amount of covalent bonding to the fibre, presumably through Michael addition at dehydroalanine residues formed from cystine degradation.

If substantive crosslinking agents could be applied then it might be expected that excellent dye-fibre covalent bonding could be achieved to produce dyeings with very high wet fastness properties. The crosslinking agent might be added either before, during or after the amino-alkyl dye application; the latter procedure should, in principle, give the most level dyeings. Crosslinking agents evaluated include hexamine, triacroylamino-hexahydro-s-triazine, methylene-bisacrylamide and 2-chloro-4.6-di(aminobenzene-4′-sul-phatoethylsulphone)-s-triazine. Hexamine and methylene-bisacrylamide are available commercially but the other agents were synthesised. Results obtained are very promising and offer potential wool dyeing methods which have better levelness than existing reactive dye systems.     

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.     

A simple one-step synthesis of unsaturated copolyesters

Copolyesters containing pendent vinylidine groups were prepared in a one-step synthesis by reacting either chloro- or bromoacetic acid with 2-(bromomethyl)acrylic acid and triethylamine in diethyl ether. Polymers were characterized by IR, ¹H- and ¹³C-NMR, DSC, and TGA. Copolymer formation supports a mechanism involving a triethylammonium carboxylate salt acting as an active nucleophilic species in a manner analogous to that seen in phase transfer catalysis involving carboxylate anions. Comparison of ¹³C-NMR spectra intensities indicates that 2-(bromomethyl)acrylic acid is much more reactive than the haloacetic acids leading to higher copolymer incorporation than in the monomer feed. Unsaturation in the copolymers provides a site for crosslinking during radical polymerization with an added vinyl monomer, similar to the way unsaturated polyesters function in commercial fiberglass formulations. This was confirmed by polymerization of both styrene and methyl methacrylate in the presence of an unsaturated copolymer giving insoluble semi-interpenetrating networks. These unsaturated copolymers are the first examples of soluble biodegradable glycolic acid polyesters containing such reactive functionality.     

Linear low‐density polyethylene colored with a nanoclay‐based pigment: Morphology and mechanical,thermal, and colorimetric properties

In this study, a novel kind of hybrid pigment based on nanoclays and dyes was synthesized and characterized. These nanoclay‐based pigments (NCPs) were prepared at the laboratory with sodium montmorillonite nanoclay (NC) and methylene blue (MB). The cation‐exchange capacity of NC exchanged with MB was varied to obtain a wide color gamut. The synthesized nanopigments were thoroughly characterized. The NCPs were melt‐mixed with linear low‐density polyethylene (PE) with an internal mixer. Furthermore, samples with conventional colorants were prepared in the same way. Then, the properties (mechanical, thermal, and colorimetric) of the mixtures were assessed. The PE–NCP samples developed better color properties than those containing conventional colorants and used as references, and their other properties were maintained or improved, even at lower contents of dye compared to that with the conventional colorants. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013