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|Title:||Study of the improvement of dyeability and other functional properties of curcumin||Authors:||Boonroeng, Supannee||Degree:||Ph.D.||Issue Date:||2016||Abstract:||Nowadays, the interest in natural dyes for textile application has been increasing due to the carcinogenic problems of certain petroleum-based synthetic dyes to human beings and animals and their difficulty in decomposition. In this work, curcumin was selected as a substantive natural dye which could be a potential alternative to synthetic yellow dye for textile coloration. The aims of the research are to investigate the dyeability of curcumin and to further develop useful functions and properties based on the chemical modification of curcumin. The research work started with the extraction of the curcumin from dry turmeric powder. The curcumin dye was then applied to dye cotton and other 3 synthetic substrates using conventional dyeing methods. The colors of the dyed samples were different shade of yellow with medium color strength. Polyester fabrics and acrylic yarns dyed exhibited satisfactory results of colorfastness to laundering and other, i.e., PLA and cotton exhibited low colorfastness to laundering. To improve dyeability and antibacterial activity of curcumin dye, the incorporation of N-phthaloyl glycine moiety into the structure of curcumin was attempted. Monoester curcumin with molecular weight of 555.53 was obtained as a major product. The modified curcumin with N-phtaloyl protecting group was investigated for its dyeability and antibacterial activity. Color of monoester curcumin on polyester fabric was greenish yellow but remained unchanged as concentration of monoester curcumin increased. Its color strength on polyester fabric compared to that of curcumin-dyed polyester fabric was lower. These dyeing characteristics were in consistence with the occurrence of hypsochromic (blue) shift and hypochromic effect as indicated by the absorbance values of monoester curcumin. For antibacterial activity, monoester curcumin exhibited lower antibacterial activity than unmodified curcumin possibly due to the disappearance of a phenolic group.
In another chemical modification of curcumin, glycidyltrimethylammonium chloride (GTMAC) was chosen to introduce the quaternary amino moiety onto curcumin molecules via etherification reaction. The major product was characterized and identified as a quaternary ammonium cationized curcumin. As the result of the absorbance measurement, the maximum absorption wavelength of the GTMAC-modified curcumin or CurGTMAC was shifted to the region of ultraviolet radiation at 346 nm possibly due to the replacement of hydrogen atom of a phenolic group of curcumin with a quaternary ammonium group. From in vitro cytotoxicity test using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and skin irritation test according to ISO 10993-10:2010, neither skin irritation nor obvious sign of cytotoxicity to the normal human skin fibroblast cells up to 125 μg/ml was observed. To increase the fixation between CurGTMAC and cotton, citric acid (CA) was primarily introduced to treat cotton fabric. Unreacted carboxyl group of citric acid remaining on CA-treated cotton may become ionized and subsequently react with CurGTMAC molecules in water during dyeing process. The color of dyed cotton was yellow with less saturation (C*) and more greenish tint compared to that of the unmodified curcumin-dyed cotton. The color strength (K/S) value at the concentration of 2 % o.w.f. of dyed cotton at the maximum absorption wavelength was 1.95. In consequence of hypsochromic shift to near UV region with a high molar extinction coefficient (εmolar) of 1,844 M⁻¹cm⁻¹, the treated cotton dyed with CurGTAMC was investigated for UV absorbing properties. The UPF rating of the treated cotton dyed with 1 % o.w.f. of CurGTMAC was higher than 100 according to AS/NZS 4399:1996. After 6 accelerated laundering cycles, equivalent to 30 home laundering cycles, UPF rating remained higher than 40 indicating the durability of UV-protection of the dyed cotton against accelerated laundering. With the knowledge of antibacterial property for curcumin, dyed samples were evaluated for their antibacterial property against both S.aureus and E.coli. The results showed that both curcumin and CurGTMAC provided bacteriostatic rather than bactericidal properties and CurGTMAC showed higher percentage of bacterial reduction than curcumin. The reaction of curcumin with glycidyltrimethylammonium chloride in an aqueous system can be an indication of the successful use of renewable resources; that is curcumin and water. The use of water as a reaction media is currently gaining an importance in organic synthesis since it is more environmentally friendly and contributes less pollution to the environment compared to the use of volatile organic solvents. Moreover, the modification reaction conducted in this work could produce the modified curcumin possessing better properties in water solubility, dyeability, and antibacterial property on cotton and gaining additional UV protective property. It also can be an initiation to develop natural dyes to be more valuable and useful than their original structures.
|Subjects:||Dyes and dyeing -- Textile fibers.
Hong Kong Polytechnic University -- Dissertations
|Pages:||xviii, 203 pages : illustrations|
|Appears in Collections:||Thesis|
View full-text via https://theses.lib.polyu.edu.hk/handle/200/8534
Citations as of May 15, 2022
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