| Summary: | 碩士 === 國立臺北科技大學 === 化學工程與生物科技系化學工程碩士班 === 106 === In this study, the preparation of a mordant chelating natural hair dye that demonstrated color fastness on hairs was considered as being environmentally friendly. Laccase was applied to catalyze three plant phenolic acids which included ferulic acid, syringic acid and gallic acid as dyeing agents. In order to explore the effects of different environments on laccase activity and hair dyeing effectiveness, the study was focused on the variation of experimental factors, including different ratios of three phenolic acid, pH, temperature, and time. Finally, we analyzed how to achieve the best dyeing conditions by obtaining the maximum color difference of △E*on hairs. These experiments were designed to use ultrasonic mixing method to synthesize the dye solutions, the results showed a contribution to shorten the 50% color generation time of them. Even so, the processing time of hairs with dyeing solution still needed to be completed in 24 hours, and then the reddish-brown hairs were reached. To further shorten the whole process time of hair dyeing, the metal mordants were added acting as a linking agent between the dyes and hairs in a chelating manner that enhance the color fixing strength on hairs. In this study the 〖Fe〗^(3+) ion was used as the metal mordant dye to make the hair colors more diverse. According to the solution properties of different metal-salt compounds, these experiments were focused on the variation of the metal ion concentration and pH value at the appropriate temperature, and then the final target Lab change of hair color difference. In conclusion, experimental results showed that the hair dyeing time assisted with mordant 〖Fe〗^(3+) would reach the target Lab change within 3 hours. As compared with laccase-preformed natural phenolic acid dye, the whole processing time of hair dyeing assisted with mordant 〖Fe〗^(3+)was shortened by 91.7%. After that, the color fastness on dyed hairs was tested by UV light exposure and soap-washing experiments, respectively. For the results of UV light exposure tests, the color difference of the phenolic acid dyed-hairs by UV light discoloration was found above 5 and that of the mordant-assisting dyed-hairs maintained below 4. In addition, the standard deviation in K/S value of the phenolic acid dyed-hairs is up to 1.269, while that of the mordant-assisting dyed-hairs is below 0.163. The DEcmc value of both phenolic acid and mordant-assisting dye-hairs showed a positive increase after five cycle times of soap-washing. However, according to the experimental results, the average K/S value of the phenolic acid dyed-hairs was reduced by 47.55% and that of the mordant-assisting dyed-hairs was reduced by 18.53% after the fifth washing cycle. In summary, the combination of phenolic acid dye and the metal mordant dye is effective to shorten the whole dyeing time and increase the color fastness on hairs. Ferric chloride was found to be the most suitable metal mordant for hair dyes of the target color and strength.
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