Two dyes namely p-hydroxyazo-3-benzene carboxylic acid and 1-(3-hydroxyphenyl azo )-2-naphthol were synthesized. The dyeing performance of these dyes was evaluated on nylon fabric at three different temperatures, namely 50°C, 70°C and 90°C.
The thermodynamics parameters such as percentage dye exhaustion (%E), Partition coefficient (K), change in Standard affinity (∆μ^(θ )), Standard enthalpy change (∆H^θ) and Standard change in entropy (∆S^θ) of these dyes on nylon fabric were investigated.
The results show that the thermodynamic parameters values of these dyes on nylon fabric vary directly with temperature. Dye p-hydroxyazo-3-benzene carboxylic acid and 1-(3-hydroxyphenyl azo )-2-naphthol had (82% and 65%)%E, (19.86 KJmol-1 and 16.79 KJmol-1 ) ∆μ^θ , (-15.32 and -12.83 KJmol-1) ∆H^θ and (0.097 and 0.078 Jmol 1K-1) at 90 oC respectively.
Contents
Introduction
Materials and method
Discussion of Results
Effect of temperature on % exhaustion
Effect of Time on % exhaustion
Thermodynamic of dyeing
References
Appendix
Abstract
Two dyes namely p-hydroxyazo-3-benzene carboxylic acid and 1-(3-hydroxyphenyl azo )-2-naphthol were synthesized. The dyeing performance of these dyes were evaluated on nylon fabric at three different temperature i.e (50 oC, 70 oC and 90 oC).The thermodynamics parameters such as percentage dye exhaustion (%E), Partition coefficient (K), change in Standard affinity ( ),Standard enthalpy change( ) and Standard change in entropy( ) of these dyes on nylon fabric were investigated. The results showed that the thermodynamic parameters values of these dyes on nylon fabric vary directly with temperature. Dye p-hydroxyazo-3-benzene carboxylic acid and 1-(3-hydroxyphenyl azo )-2-naphthol had (82% and 65%)%E, (19.86 KJmol-[1] and 16.79 KJmol-[1] ) , (-15.32 and -12.83 KJmol-[1]) and (0.097 and 0.078 Jmol‑[1]K-[1]) at 90 oC respectively.
Keywords; Azo Dye, Thermodynamic, Enthalpy, Percentage exhaustion and partition coefficient.
Introduction
Dyes are type of organic compounds that con provide bright and lasting colour to other substance (Gong et al., 2005) there are more than 100,000 dyes available commercially, which are specially designed to resist fading upon, exposure to light water and oxidized agent s and, as such are very stable and difficult to degrade (Nigam et al., 2000). Synthetic dyes have been increasingly used in textile, leather, paper, rubber, plastic, cosmetic, pharmaceuticals and food industries (Said et al., 2012).
In general, acid dyes have attracted much attention to nylon substrates due to their interaction mechanism and easy method for application (Yoon et al., 2001). However, to achieve satisfactory levels of wash fastness, recourse is required to an after treatment with a commercial system and other fixing systems. While after treatment of the dyed nylon substrates can be improve wash fastness, this treatment can impart a change in shade of ground colour but also it is temporary in nature (Burkin shaw and Son, 2001). Most acid dyestuffs acquire their acidity from the present of sulphonic acid groups (-SO3) or nitro (-SO2) groups in the molecules (Nkeonye, 1987). Acid dyes being water soluble anionic dyes are applied primarily to nitrogenous fivers such as wool, silk and nylon, all of which contain basic groups. They provide a complete colour range, Varying from yellow to black, many of the being very bright (David, 1990). Out of different classes of dyes, azo dyes constitute the largest group of colourants used in industry (Zollinger, 1987). Azo dyes do not occur in nature and are produced only through chemical synthesis (Maynard, 1983). The emergence of diverse classes of synthetic dyes including azo-dye occurred due to constant effort to find specific dye or a particular class of dye for application an diverse materials of industrial importance mainly textile fibres, aluminum sheet, leather, electro optical devices, Ink-jet printers etc. (catino and Farris, 1985) .
Materials and method
2.1 Materials
Nylon fibre
Dyes
2.2 Method
The principal method of forming of forming azo involves Diazotization of primary amines followed by coupling with hydroxyl or amino derivatives of aromatic hydrocarbons or with certain aliphatic keto compound.
2.2.1
Diazotization is the process of converting an amine into diazonium salt. When a cold solution of primary aromatic amines in a dilute mineral acid (Hcl) is treated with cold solution of nitrous acid at about 0-5[0]C, a diazonium salt is formed. Nitrous acid (HNO2) is formed when sodium nitrite and mineral acid (HCl) reacted together
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Ar is an aryl group, Aryl diazonium chloride
2.2.2 Coupling
Azo compounds are prepared by the interaction of a diazonium salt with a coupling agents like Phenol in the presence of NaOH or with an amino in the presence of sodium acetate (CH3COONa) The Coupling reaction is an electrophilic substitution involving the diazonium ion which reacts at the position of greatest electron availability i.e position ortho or para to the electron releasing phenoxyl or amino groups.
2.3 Experimental synthesis of P-hydroxy azo-3- benzene carboxylic acid
2.3 1 Diazotization : 3- benzene carboxylic acid .
45 ml of aniline was measured and poured into 40 ml of HCl, the solution was heated gently in a hot temperature.1 M NaNO2 solution was produce by measured 6.90 g of NaNO2 in 100ml of water stirred and kept in an ice bath. It was stirred rapidly and continuously to facilitate cooling to less temperature of 5 [0]C
2.3.2 Coupling of 3- benzene carboxylic acid .
6.91 g (0.05mol) of salicylic acid was dissolved in 38ml of 2.5.M NaOH. The mixture was stirred at (0-5)[0]C for 15minutes. It was then heated in hot water bath until solid dissolved. 17.65 g of NaCl was added to further decrease the solubility of the product.
Synthesis of 1-(3-hydroxyphenylazo) -2- naphthol
2.3.3 Diazotization: 3-aminophenol
10.9 g of 3-aminophenol was placed into 250 ml of water in a 500 ml beaker. 40 ml of concentrated hydrochloric acid was slowly added until 3-aminophenol dissolve completely. The solution was cooled in the ice bath. 3-aminophenol precipitates out upon cooling while the solution kept at (0-5)[0]C NaNO2 was slowly added with a dropper and stirred thoroughly for 2-3 minutes
2.3.4 Coupling of 3-aminophenol
7.2g of 2-Naphtol was dissolved in the sodium hydroxide solution and the mixture was stirred until complete dissolution, the solution was cooled in an ice bath. The benzene diazonium salt solution was slowly added to the 2-naphthol solution. A brick red precipitate is formed.
Discussion of Results
Effect of temperature on % exhaustion
It is evidently clear from table 1 and 2 that temperature change affects dyeing and percentage exhaustion. All dyes showed high % exhaustion at temperature near the boiling point. The percentage exhaustion increased with increased in temperature. This is so, because, there is grater segmental mobility of the fibre polymer chains action of the dye molecule into the fibre (Moncrieff, 1975). At 50o % exhaustion of dye 1 and2 are (48% and68%), at 70oc % exhaustion of dye 1 and 2 are (53% and 72%), while % exhaustion at 90oc are (65% and 85%) respectively, this shows that the adsorption of dyes 1 and2 on nylon improved with rise in temperature up to 90oc for the dyes indicate that high temperature favoured the dye adsorption into nylon fibre (Ali et al., 2009). The increase in temperature increase the mobility of large dye, as well as produced swelling effect with the internal structure for more, thus enabling the large dye molecule to penetrate further (Yoshida et al., 1993, venkatet et al., 2007). This may also due to an increase in the mobility of dye molecules with an increase in their kinectic energy and improved the rate of intra particle diffusion of sorbate with rise in temperature (Ezeribe et al., 2013)
Effect of Time on % exhaustion
Its shown from table 1 and 2 that there is an increase in the percentage exhaustion with increase in time of dyeing, this indicate that the longer the time of dyeing, the greater the amount of dye molecules absorbed by the fibre on till an equilibrium is attained, more dye molecules penetrating into the nylon at longer dyeing time resulting in high percentage exhaustion of dye 1 and 2. Thus, percentage exhaustion increases with time (Bello et al. 2009).
Thermodynamic of dyeing
The thermodynamics parameter from table 1 and 2 show that as the temperature increases, the partition coefficient of dye increases for nylon. This indicate that the absorption of dye toward the nylon fibre as an exothermic reaction process resulting higher dying temperature gives a positive effect on thermodynamics absorption (El Gabry. 2004).
The change in standard affinity of the dye in dyeing solution towards the substrate. This parameter was defined as the differences between the chemical potential of the dye in the fibre and the chemical potential of dyeing solution. This value measures the tendency of the dye to form its standard state of the solution to its standard state of the fibre (Vicker staff, 1954). It was shown from the table above that, the standard affinities increases as the temperature increases. The enthalpy change means the amounts of the released thermal energy when dye molecules are absorbed on fabric, the enthalpy change considered as the measured of the absorption strength of the dyes (Trotman, 1984). The enthalpy change of dye 1 and 2 are (-12.55 and - 15.29) kjmol-[1] respective. Because of the negative sign of the enthalpy shows that the dyeing reaction is exothermic (Banchero, 2013; MaO et al.2013).
The entropy values for the sorption of the dyes into nylon 6 fibre were found to be (78 and 95) Jmol-[1]K-[1] respectively from table 1 and 2. Mean while, the entropy change show the extent of the reduce freedom of the dye molecules after the completion of dyeing and represent the entropy difference of the dye molecule the fibre (Kim et al.2007). The positive entropy change values suggested that the solid/solution interface during sorption increase the diffusion rate of dyes (Otutu et al.2008).
References
1) Nigam, P., Armour, G., Banat, I.M, Singh, D., and Marchant , R. Physical removal of textile dyes from effluents and solide-state fermentation of dye-adsor bedagricultural resides Bioresource technol-, 72 (2000) PP 219 - 226
2) Gong,R., Sum, Y., Chen, J. Liu H., and Yang, C. Effect of chemical modification on dye adsorption capacity of peanut hull. Dyes pigment, 67 (2005) PP 175-181
3) Said, A.A., Ludwid, A.G and aglon, H.A. Usefulness of raw bagasse for oil adsorption Acomparism of raw and acylated bagassee and their components. Bioresource Technol 100 (2009)
4) Yoon, S.H., Kim, T.K., Lim, Y.J., Y.A, Son, Y.A., and Korean, J.(2002). Society of Dyers. Finishers 14 : 35-41
5) Burkinshaw, S.M., and Son, Y.A., (2001). Dyes Pigments. 48:57-69
6) Nkeonye, P.O. Fundamental principles of Textile Dyeing, (printing and Finishing A.B.U Press Ltd. (1987), PP 135-145
7) David, R.W and Geoffrey, H. The chemistry and Application of Dyes (plenum press Newyork and London, 1990) pp203-235.
8) Zollniger, H. colorchemistry - Synthesis, Properties and Application of Organic Dyes and Pigments VCH Publisher, New York, (1987), PP 92-102.
9) Maynared, C.W. Rieqgel’s Hand book of Industrial Chemistrym, 3rd ed. Van Nostard Reinhold, New York, (1983) PP 809-861
10) Catino, S.C and Farris, R.E. ConciseEncyclopedia of chemical Technology,M. Grayson Ed., John Wiley and sons New York, (1985), PP 142
11) Ali, S., Hussain, I. and Nawaz, R(2009). Journal lf Cleaner Production 17:16
12) Yoshida,H ; Okamoto, A. and Kataoka, T.(1993). Adsorption fibers - Adsorption of acid dye on cross linked chitosan fibers-equilibra, chem. Eng.sci 48: 2267 - 2272.
13) Venkat, S.M., Indra, D.M and Vinal, C:S (2007) Uses of bagasse fly ash as an adsorbent for the removal of brilliant green dye from aqueous solution. Dyes pigment, 73:2692-278.
14) Ezeribe, A.I., Bello, K.A., Adamu, H.M., Boryo, D.E.A. and Omar, P.G. (2013). Synthesis and Dyeing Properties Of Novel Bifuntional Reactive Dyes Via 4 -(4-Nitrophenyl)-1, 3-Thiazole -2- Amine, 4-(4-Methylphenyl)-1,3- Thaizol -2-Amine and H-Acid em Nylon Fabric . IJES 2: 28-36.
15) Mancriff, R.W (1975). Man made Fibres Newness - Butter worths, London, 2nd Ed.PP37.
16) Bello. I.A., Bello, K.A., Peter, O.A. and Bello, O.S. (2009). Synthesis, Spectroscopic, Thermodynamic and Dyeing Properties of Disperse Dyes derived from 2-Amino-4- Trifluoromethyl benzothiazole . Reports and Opinion 5 : 58-66
17) ElGabry, L.K (2004). Color Technol. 120:236-240
18) Vincker staff, T. (1954)- The Physical Chemistry of dyeing 2nd Ed. London, Oliver and Boyd.
19) Kim, T.K., Son, Y.A. and Lim, Y.J(2007). Thermodynamic analysis of 1,4 -diamino anthraquione adsorption on polyethylene terephthalate in alkaline media Dye and pigment, 72: 24 6-250
20) Banchero, M>(2013) Supercritical Fluid dyeing of synthetic and natural textile A review color technology, 129:2-17
21) Mao, Y.H., Guan, Y., Zheng, O.K, Liu, Q.S., Feng, N.x and Wang, X.X (2013) . Carrier dyeing of polyphenylene sulphide fabric with disperse dye. color Tech.129:39-48
22) Otutu O. (2008) Physico-chemical studies of diazo disperse dye derivatives of P-amino phenol containing 1,4 diamino benzene moiety Journal of chemical society of Nigeria 33: 99-104.
Appendix
TABLE 1 Thermodynamic parameters of Dye 1(p-hydroxyazo-3- benzene carboxylic acid) on nylon
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TABLE 2 Thermodynamic parameters of Dye 2[1-l(3-hydroxylphenyls azo)-2-naphthol] on nylon.
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Scheme 1
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Scheme 2
Frequently asked questions
What is the purpose of this document?
This document is a comprehensive language preview of a study on azo dyes and their application on nylon fabric. It includes the title, table of contents, objectives, key themes, chapter summaries, and keywords. The text is obtained from a publishing company and contain OCR data intended solely for academic use, analyzing themes in a structured and professional manner.
What topics are covered in the table of contents?
The table of contents includes the following sections: Introduction, Materials and Methods, Discussion of Results (Effect of temperature on % exhaustion, Effect of Time on % exhaustion, Thermodynamics of dyeing), References, and Appendix.
What is the abstract about?
The abstract summarizes the synthesis and dyeing performance of two dyes, p-hydroxyazo-3-benzene carboxylic acid and 1-(3-hydroxyphenyl azo)-2-naphthol, on nylon fabric. It investigates thermodynamic parameters like percentage dye exhaustion (%E), Partition coefficient (K), change in Standard affinity, Standard enthalpy change, and Standard change in entropy at different temperatures (50 °C, 70 °C, and 90 °C). The results show that thermodynamic parameter values vary directly with temperature.
What are the keywords associated with this study?
The keywords are: Azo Dye, Thermodynamic, Enthalpy, Percentage exhaustion, and partition coefficient.
What does the introduction discuss?
The introduction provides general information about dyes, particularly synthetic dyes and their uses in various industries. It focuses on acid dyes and their application to nylon substrates, mentioning their interaction mechanism and application methods. It also discusses the challenges in achieving satisfactory wash fastness and the use of after-treatments. The prevalence of azo dyes as a major group of colorants and their synthetic origin is also highlighted.
What materials and methods were used?
The materials used were nylon fiber and the synthesized dyes. The method involved diazotization of primary amines followed by coupling with hydroxyl or amino derivatives of aromatic hydrocarbons or with certain aliphatic keto compounds. The specifics of diazotization and coupling reactions are described, including experimental synthesis of P-hydroxy azo-3-benzene carboxylic acid and 1-(3-hydroxyphenylazo) -2-naphthol.
What are the key findings regarding the effect of temperature on % exhaustion?
The study found that the percentage exhaustion of the dyes increased with increasing temperature. Higher temperatures led to greater segmental mobility of the fiber polymer chains, allowing better dye molecule penetration.
What are the key findings regarding the effect of time on % exhaustion?
The study indicates that a longer dyeing time resulted in a greater amount of dye molecules being absorbed by the fiber, leading to a higher percentage of dye exhaustion until equilibrium was attained.
What are the key findings regarding the thermodynamics of dyeing?
As temperature increases, the partition coefficient of dye increases. The absorption of dye toward the nylon fiber occurs as an exothermic reaction process. The standard affinities increase as the temperature increases and the enthalpy change shows that the dyeing reaction is exothermic. The positive entropy change values suggested that the solid/solution interface during sorption increase the diffusion rate of dyes.
What references are cited in this document?
A list of references is provided, citing various publications and research articles related to dyes, dyeing processes, and related chemical technologies.
What is included in the appendix?
The appendix includes tables showing the thermodynamic parameters of Dye 1 (p-hydroxyazo-3- benzene carboxylic acid) and Dye 2 [1-l(3-hydroxylphenyls azo)-2-naphthol] on nylon. It also includes Scheme 1 and Scheme 2, visualizing the chemical reactions.
- Citar trabajo
- Adekunle Jelili Olaoye (Autor), 2016, Thermodynamic Parameters of Two Azo Dyes on Nylon Fabric. Synthesis, Application and Determination, Múnich, GRIN Verlag, https://www.grin.com/document/342035
