Study of Some Recent Technologies of Azo Disperse Dyes on Polyester Fibers Part II Thermodynamics and kinetics Parameters of Dyeing
This present work aims to investigate dyeing performance of some new azo disperse dyes belonging to diazotization of 1, 4 bis (2 amino 1, 3, 4 thiadiazolyl) benzene and coupling with different amines as to comparing and contrasting depth obtained of shade and levelness. Some new dyes, such, has been examined, and assessed. The study was concerned mainly with dye uptake, behavior and efficiency. Color measurements, kinetics and thermodynamic parameters were involved. Conventional dyeing, was considered as control for obtained results. (c) 2017 Elixir All rights reserved. Elixir Appl. Chem. 106 (2017) 46546 46551 Applied Chemistry Available online at www.elixirpublishers.com (Elixir International Journal) Tele: 00201155011735 E mail address: dr_ali055@yahoo.com (c) 2017 Elixir All rights reserved M. S. Aboul Fetouh et al. Elixir Appl. Chem. 106 (2017) 46546 46551 46547 supplied by Egyptian Turkish Co. (Cairo, Egypt) and 2 g/L of Na2CO3 at 50 degC for 30 min to remove waxes and impurities, then rinsed thoroughly in cold tap water, and dried at room temperature. II.4. Carrier and/or solvent assisted Dyeing Process: Dyes were used as pure powder in the same form as prepared without milling. Fabric samples (2 g) were introduced into a flask containing a dye bath of 4% (o.w.f) dye shade and Avolan as dispersing agent, commercial HC carrier (Liquid) supplied by Egyptian Turkish Co. (Cairo, Egypt) for auxiliaries with ratio 4% (o.w.f) and/or n butanol with ratio 6% at dyeing temperature 100degC with a 1:50 liquor ratio. During dye bath preparation, the dye was mixed with 10 drops of DMF and then mixed with dispersing agent, and water was added to prepare a homogeneous dispersion of the dye. The pH was adjusted to 4.5 by using acetic acid. At the end of the dyeing process after 1 h, the dyed samples were removed, rinsed in warm water, and subjected to reduction clearing in a solution comprising 2 g/L of sodium hydrosulphite and 2 g/L of sodium hydroxide (caustic soda) for 10 min at 60degC, with a liquor ratio of 1:40, This was aimed at removing unfixed dye and carrier residues that may be left on the fabric after dyeing and the reduction cleared sample was rinsed thoroughly in water. The dyed samples were removed, rinsed in tap water, and allowed to dry in the open air. [3] II.5. High temperature dyeing method (HT) A dispersion of the dye was produced by dissolving the appropriate amount of dye (2% shade) in 1 mL dimethylformamide (DMF) and then added drop wise with stirring to the dye bath (Liquor ration 50:1) containing 4% a volane as dispersing agent. The ratio of dispersing agent to dyestuff is 1:1. The pH of the dye bath was adjusted to 4.5 using aqueous acetic acid and the wetted out polyester fabrics were added. Dyeing was performed by raising the dye bath temperature to 130degC and high pressure (24 30 psi) for 60 min under pressure in an infra red dyeing machine. After dyeing, the fabrics were thoroughly washed and subjected to surface reduction clearing (2 g NaOH 2 g sodium hydrosulphite)/L, and soaped with 2% nonionic detergent to improve washing fastness) The samples were heated in this solution for 45 min at 80 degC. Rinse well in cold water and neutralize with 1g/L acetic acid for 5 min at 40degC, the dyed samples were removed, rinsed in tap water and allowed to dry in the open air. [1] II.6. Exhaustion Isotherms The rate of exhaustion of the dyestuffs on polyester fiber was measured at equilibrium at 100degC, according to previous methods. The rate of exhaustion was assessed by taking samples from the dyebath at different times during the dyeing process. The optical density of the dye bath samples was then measured using a UV visible spectrophotometer. II.7. Thermodynamics and kinetics parameters [4] II .7.1. Partition coefficient and standard dyeing affinity The partition coefficient, K, of the dye concentration between the fiber and the dyeing solution was obtained from the adsorption isotherm. The standard affinity of the dye was calculated using the following equation. K [D]f [D]s (1) Dmdeg RTlnK (2) K, The partition coefficient. Dmdeg, standard dyeing affinity [D]f ,dye concentration in fiber on adsorption isotherms [mol/kg] [D]s, dye concentration in solution on adsorption isotherms [mol/kg] T, absolute temperature [K] R, gas constant [1.9872cal/mol.K] II.7.2. Heat of dyeing DH 0 and entropy change DS 0 DH 0 and DS 0 can obtained from the empirical plot between Lin k and 1/T using Eq.2 and 3. DH D G100 T100DS (3) DH ,heat of dyeing[cal/mol] DS change of entropy[cal/mol.K] T, absolute temperature [K] R, gas constant [1.9872cal/mol K] III. Results and Discussion (Cpd 1) Yield 22 m.p 343 344 degC, yellow crystals, IR bands (KBr pellets cm 1 3280 and 1505 n (NH) and d (NH) 3085 n(C H, ar. 1689 n(C=N) 1424 n(C=C ar. 1070 n =N N= 731 d(C S C) Mass spectra of compound 1 gave molecular ion peak at m/z 276 (M +1 corresponding to molecular formulaC10H8N6S2. (Dye 1) Yield 83 m.p 284degC, reddish orange crystals, lmax in DMF/H2O 361 and IR bands (KBr pellets cm 1 3379 and 1503 n (NH) and d (NH) 3063 n(C H, ar. 1620 n(C=N) 1414 n(C=C ar. 1015 n =N N= 690 d(C S C) The molecular formula is C22H14N8S2O2 (484) and the elemental analysis is C (54.53) H (3.33) N (28.91) S (13.23) and also good agreement with structure data. Dye 2: Yield 81 m.p>300degC, Dark red crystals, lmax in DMF/H2O 552, and IR bands (KBr) max/cm 1 3380 and 1510 (NH) 3052 (C H, ar. 1686 (C=N) 1420 (C=C ar. 1014 =N N= 732 (C S C) Molecular formula C30H20N10S2 (584) and the elemental analysis is C (61.63) H (3.45) N (23.96) S (10.97) and also good agreement with structure data. III.1. Dyestuffs Synthesis Thiadiazole is an important five membered heterocyclic ring containing two nitrogen atoms for synthesis sulphur dyes. The target 5, 5' (1,4 phenylene)bis(1,3,4 thiadiazol 2amine) (1) was synthesized by the reaction of terphthalic acid with thiosemicarbazide in the presence of phosphorus oxychloride The disappearance of C=O stretching in IR spectra was good indication of conversion of terphthalic acid to heterocyclic ring, in addition to the following frequencies: NH2, 3280, 1505 cm 1 due to NH stretching, 1689 cm 1 for C=N and 731 cm 1 for C S ring stretching, Fig. (1) (1) Fig 1. Structure of compound (1) The dyes 1 and 2 were diazotized and coupling with different amines to form disperse dyes used for the dyeing of polyester fibre; Fig. 2. The structural identification of synthesized dyes 1 and 2 have been confirmed from both spectral and elemental analysis. III.2. Application of prepared dyes on textile fiber Disperse dyes (2 5) were applied to polyester fabrics at 4% (shade) using high Temperature dyeing method (HT) at 130degC HC carrier with ratio 4% (o.w.f) at dyeing temperature 100 o C Solvent assisted dyeing using 6% high molecular soluble solvent (n butanol) Above techniques are assist in comparison against conventional dyeing at the boiling (100degC) M. S. Aboul Fetouh et al. Elixir Appl. Chem. 106 (2017) 46546 46551 46548 Figure 2. Reaction scheme. III.3. Solvent assisted against carrier dyeing of polyester The use of n butanol at about 60 ml/l in the dye bath considerably accelerates the diffusion rates of disperse dyes in polyester, and is capable of improving the levelling properties of the dyes and shortening the time required at top temperature to give full yields. In all these respects, however, its performance is similar to that of conventional carriers used at much lower concentrations about 2 g/l. Without solvent recovery, the cost of the solvent assisted dyeing method would be much greater than that of methods using conventional carriers, with no increase in performance. Solvent recovery is, therefore, crucial if the solvent assisted process is to be commercially viable. It might then show advantages over the use of carriers on a throw away basis, both in cost and in reducing the problems of effluent disposal, from which most conventional carriers are likely to suffer increasingly in the future. It is apparent that the improvement in coverage increases very steadily with increased concentration of butanol, up to the region of 5% by weight in the dye bath. In subsequent work, therefore, this concentration of solvent was used in most cases [5] III.4. Dyeing characterization on polyester fabric For some time an effort has been made to replace certain anthraquinone disperse dyes by new dyes often derived from hetero compounds to improve the properties. Useful dyes in this respect are derived from 2 amino 1, 3, 4 thiadiazole derivatives as diazonium components and amines or phenols as coupling components. Thus dyes were synthesized to assess their dyeing properties and performance. All these dyes were used for dyeing polyester fabric at 4% (w/w) shades as dispersed dyes. Variation in the shades of the dyed fabric results from both the nature and position of the substituent present on the diazo component. A remarkable degree of levelness and brightness after washing indicates good penetration and excellent affinity of these dyes to the fabric. [6] III.5. Kinetic and thermodynamic behavior of some extracted dye on polyester III.5.1. Exhaustion Isotherm Dye solutions (4% were prepared from the crude extract by maintaining material to liquor (MLR) ratio at 1:50. The absorbance of the dye solution was recorded before and after dyeing process with UV Visible spectrophotometer. The per cent dye uptake was calculated using the following formula. [7] Table 1. Comparative study of efficiency for dye (1) on polyester by different dyeing method. Dyeing Condition Temperature of dyeing (C) dye take up Half time of dyeing t1/2 Conventional 100 55.6 21 High temp 130 91.44 17 Carrier dyeing 100 60.4 18 Solvent assisted 100 73.7 19 80degC dyeing 80 51.1 21 Table 2.Comparative stu