Effect of nanoclays on the dyeability of polypropylene nanocomposite fibres

Polypropylene clay fibres loaded with different alkylammonium-modified montmorillonite were prepared using a melt spinning technique and relationships between the structure and properties of the nanopolypropylene fibres are discussed. Experiments carried out using transmission electron microscopy showed that the chemical structure of the organic modifier and the interlayer spacing of the clay induced different dispersions of the clay, thus improving accessibility of the nano fibre. It is known that nanoclays are effective and efficient sorbents for dyes. Therefore, the dyeing behaviour of the nano polypropylene fibres with two distinct acid dyes and a disperse dye was studied and the build-up of dyes, measured as colour yield, reported. The best results were obtained when the clay was well dispersed in nanopolypropylene fibres; that is, when maleated polypropylene was added as a compatibiliser and when disperse dye was used. Good wash fastness was then obtained.     

New cationic agents for improving the dyeability of cellulose fibres. Part 2-pretreating cotton with polyepichlorohydrin-amine polymers for improving dyeability with reactive dyes

Pretreatment of cotton with polyepichlorohydrin-dimethylamine produces a modified cotton that can be dyed under neutral conditions with selected low-reactivity dyes using a small amount of salt or with selected high-reactivity dyes without salt. The dyeings of treated cotton exhibit improved colour yield and high wash fastness. The properties and the quality of the reactive dyeings are discussed.     

Preparation and characterisation of luminous polypropylene/phosphor strontium aluminate nanocomposite fibres with enhanced dyeability

Phosphor strontium aluminate (SrAl₂O₄: Eu²⁺, Dy³⁺) nanoparticles, SAOED, were melt compounded with polypropylene on an internal mixer to prepare a uniform mixture with polymer and the resulting materials were granulated. PP/SAOED nanocomposite fibres were then produced by melt spinning method at the take-up speed of 1000?m?min^?1. Morphological, thermal, structural and luminescent properties of the luminous fibres were studied by SEM, differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and fluorescence spectrophotometer. The luminous fibres were then knitted and dyed to investigate the effects of SAOED nanoparticles on the dyeability of fibres. SEM results showed that with increasing SAOED nanoparticle amounts, the agglomerates of SAOED nanoparticles were appeared on the fibre surface. DSC results indicated that the SAOED nanoparticles did not affect melting and crystallisation behaviours significantly. WAXD patterns revealed that the crystal type of luminous nanocomposite fibres did not change and was still the α-monoclinic crystal form. The luminous nanocomposite fibres were found to have inferior tensile properties as compared to the neat PP fibre. From fluorescence spectrophotometer results, it can be seen that fibres excited at the wavelength of 400?nm, showed an emission peak at 550?nm and had green light. With increasing the amount of SAOED nanoparticles in the fibres, emission peak intensity of luminous fibres increased and also the fabric dyeability was improved.     

New cationic agents for improving the dyeability of cellulose fibres. Part 1 — pretreating cotton with polyepichlorohydrin-amine polymers for improving dyeability with direct dyes

Cotton fibres were treated with polyepichlorohydrin—dimethylamine and dyed with a selection of direct dyes. The pretreatment was found to reduce the amount of sodium chloride needed, and to increase exhaustion efficiency and perspiration fastness. The preparation and chemical characteristics of polyepichlorohydrin-dimetnylamine, the dyeing of the modified cotton and the quality of the direct dyeings are also discussed.     

Flame retardant polypropylene fibers with good dyeability

Polypropylene has been grafted with pentabromobenzyl acrylate by reactive extrusion. The degree of grafting is about 4% by weight of the polypropylene independent of the weight of brominated monomer in the feed. Ungrafted monomer remains largely unreacted. Fibers spun from the grafted polypropylene display good mechanical properties and are easily dyed with anthraquinone type disperse dyes. The dyed cloths have good color stability even after laundering. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 601–606, 1997     

Investigation of the improved dyeability of cationised cotton via photografting with UV active cationic monomers

In this study cotton fabric was photografted with cationic monomers using UV radiation. The dyeability of cationised cotton, in the absence of salt, with three classes of dye (direct, reactive and sulphur dyes) was significantly improved due to the increased ionic attraction between the dyes and the cationic cotton. The colour fastness of the cationised fabric was similar or better than that of the untreated fabric. In addition, when cationised, crosslinked crease-resist cotton also showed improved dyeability, in the absence of salt, to direct dyes.     

New methods for improving the dyeability of cellulose fibres with reactive dyes*

Cellulose fibres may be dyed with reactive dyes in the absence of added electrolyte under neutral to slightly acidic conditions provided the fibre is modified to include cationic sites. The effect of amine substitution has been examined in detail using the activated substrate prepared by the reaction of cotton with N-methylolacrylamide. Dyes containing pendant aliphatic amino groups were also prepared and their reactivity towards the pre-activated cotton substrate assessed.     

Modification of the surface of polyacrylonitrile fibres before oxidation with a dispersion of technical carbon

Conclusions -- The possibility of using dispersions of technical carbon in a medium of ethylene glycol, an aqueous solution of a binder of the Sokrat-binder type, or an alcoholic solution of polyvinyl butyral for the modification of polyacrylonitrile fibres before thermo-oxidation, which ensure obtaining a stable and uniform carbon-containing film on the fibre surface has been established.-- The use of ethylene glycol as the dispersion medium leads to retention of the strength of fibres after heat treatment at the level of the starting fibres and reduces the specific bulk electrical resistance.-- Application of aqueous solutions of the Sokrat-binder aids in preserving fibre strength during thermo-oxidation. The linear density of the fibre and its ability to be oxidized are increased, but the specific bulk electrical resistance and elongation are reduced.-- The use of alcoholic solutions of polyvinyl butyral makes it possible not only to preserve fibre strength but also to considerably increase it during the thermo-oxidation process. Thereupon, the linear density of the fibres is significantly reduced, and at a dispersion content of 10% by wt. technical carbon, one can obtain electrically-conducting oxidized fibres.Translated from Khimicheskie Volokna, No. 4, pp. 36–37, July–August, 1991.     

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     

Modification of silk with aminated polyepichlorohydrin to improve dyeability with reactive dyes

Reactive dyes have almost complete exhaustion and ideal fixation on aminated polyepichlorohydrin pretreated silk without addition of salt or alkali. The effects of varying pretreatments and dyeing conditions were studied. The dyeing behaviour of CI Reactive Red 15 on modified silk under pH 6 was investigated. Dyeings of modified silk showed good wash fastness, dry and wet rub fastnesses as well as light fastness. The quality of the dyed silks obtained after pretreatment was shown to be satisfactory and the dyeing effluent was less polluted.     

Alkylaminoanthraquinones as dyes for polypropylene fibres

The synthesis of a series of 1-alkylaminoanthraquinones is described. In general, dyeing properties and light fastness of these compounds on unmodified polypropylene fibres improves with increase in length of the alkyl chain. The presence of the n-octadecylamino group is particularly advantageous and a range of new dyes containing this substituent is described.     

Oil for polypropylene and polyester fibres

An analysis of the basic characteristics of samples of the new product Avivazh NTP with a different liquid paraffin content and a comparison with the properties of Hansa oil, highly recommended in synthetic fibre production, showed that Avivazh NTP No. 4 (6% liquid paraffin content) and NTP No. 5 (10% liquid paraffin content) is superior to the imported product with respect to its properties. Translated from Khimicheskie Volokna, No. 2, pp. 37-40, March-April, 2009.     

Modification of cellulose with N-(2-chloroethyl)diethylamine hydrochloride: mechanism of improved dyeability with 5-chloro-2,4-difluoropyrimidinyl dyes

Monofluorotriazinyl and 5-chloro-2,4-difluoropyrimidinyl dyes were each reacted, in turn, with trimethyl- and triethyl-amine in aqueous solution. Trimethylamine was quaternised by both the fluoroheterocyclic reactive dyes. In the case of the chlorodifluoropyrimidinyl dye, NMR spectroscopy showed that displacement of the C-2 fluorine atom had occurred. Triethylamine, on the other hand, failed to react with either fluoroheterocycle, strongly suggesting that the covalent bond formation reaction of DEAE-cotton, with a 5-chloro-2,4-difluoropyrimidinyl dye under neutral conditions, does not involve initial quaternisation. A mechanism involving the deprotonation of the cellulose hydroxy groups, catalysed by the basic groups in DEAE-cotton, is proposed.     

Preparation of sulfonated polypropylene and its dyeability: Thiol as a functionalization template of polypropylene

A two-step process has been invented to prepare sulfonated polypropylene from chlorinated polypropylene via thiolation and successive oxidation to enhance the dyeability of polypropylene. With a short thiolation reaction time of 3 h in an N-methyl-2-pyrrolidone solution, 1.7–20.5% sulfur can be incorporated into a polypropylene bulk effectively. Chlorine–thiol substitution and hydrosulfide conversion have been examined with elemental analysis, and their behaviors as a function of the SH/Cl ratio can be explained with an equilibrium model of hydrosulfide and accessible chlorine in a given timescale. Oxidation of thiol has been performed successfully with hydrogen peroxide. The evolution of oxidation intermediates such as sulfoxide, sulfone, sulfinic acid, and sulfonic acid can be identified by Raman and Fourier transform infrared analyses. Sulfonated polypropylene can be stained by a basic dye very effectively, and its dye uptake reaches 190 mmol of dye/kg of polymer for 3.6 mmol of sulfur/g of polymer. This dye uptake is 20 times more effective than that of chlorinated polypropylene on a molar basis. Thus, it is clear that a modification can be performed effectively to enhance the dyeability of polypropylene. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

纳米碳酸钙改性聚丙烯

研究了不同牌号的聚丙烯（PP）与纳米CaCO3复合材料的力学性能,考察了双螺杆挤出和密炼混合工艺及相容剂含量对PP／纳米CaCO3复合材料力学性能的影响,采用透射电子显微镜观察了纳米CaCO3在PP中的分散情况。结果表明,纳米CaCO3对不同牌号的PP均有增韧作用,对基材韧性较好的共聚PP增韧效果较显著．冲击强度提高了81％;双螺杆挤出和密炼混合均能使纳米CaCO3粒子在PP中达到较好的分散。     

Polyamide fibres with improved properties

Technology was developed for impregnating polyamide fibres with phosphorus- and boron-containing compounds with fireproofing properties. The effect of the formula for the impregnating compositions on the physicomechanical properties and combustibility of the fibres was determined. The compositions increase adhesion of polyamide fibres to vulcanized chloroprene rubber.