【作者】 柴丽琴；

【导师】 邵建中； 周岚；

【作者基本信息】 浙江理工大学 ， 纺织化学与染整工程， 2010， 硕士

【摘要】 天然染料源于自然,环境生态相容性好,生物可降解,对人体健康无害,符合现代人们对自身健康以及对环境保护重视的要求。但是,大多数天然染料对棉纤维染色存在上染率低和色牢度差的问题。针对上述问题,本课题研究开发棉纤维的阳离子化改性技术,并将其应用于棉纤维的天然染料染色,有效地改善天然染料在棉纤维上的染色性能。本论文分别应用反应型改性剂H和非反应型改性剂BE-2对棉纤维进行阳离子化改性,优选了改性工艺和天然染料在改性棉织物上的染色工艺。通过可见光谱分析研究了多种天然染料的稳定性;通过热重分析和Zeta电位分析研究了改性前后棉织物热性能和织物表面的电位变化情况;通过白度、顶破强力、含水率和回潮率等测试研究了改性前后棉织物的物理机械性能;通过制作上染速率曲线和吸附等温线,深入研究了天然染料在改性棉织物上染色的动力学和热力学性能。以改性剂H作为棉纤维反应型阳离子化改性的改性剂,优化的改性配方为:改性剂H浓度4% (o.w.f),平平加O浓度0.6-1%(o.w.f),氢氧化钠0.5-1g/L,浴比1:30;优化的改性工艺为:常温升温至70℃,保温30分钟,加氢氧化钠,反应20分钟,取出水洗。以BE-2作为棉纤维的非反应型阳离子化改性的改性剂,优化的改性工艺为:改性剂BE-2 4%(o.w.f),常温升温至70℃,保温10-15 min,浴比1:30。棉纤维经上述两种改性方式改性后,Zeta电位明显趋正,热稳定性略有下降,物理机械性能没有显著变化。天然染料染色棉织物具有较高的得色量,较好的色牢度和匀染性,以及优异的紫外防护性能。为了提高对天然染料在棉纤维上染色过程的控制和对染色工艺优化的理论指导作用,本论文研究了天然染料在改性棉纤维上的染色动力学和染色热力学。运用准一级动力学模型和准二级动力学模型对改性棉纤维上三种天然染料染色的实验数据进行模拟,计算天然染料在改性棉纤维上的染色动力学参数;运用Langmuir、Freundlich和Nernst 3种理论模型对改性棉纤维上三种天然染料染色的热力学实验数据进行拟合,计算天然染料在改性棉纤维上的热力学参数。结果显示:三种天然染料在阳离子化改性棉纤维上的染色动力学符合准二级动力学模式,即支持吸附过程包括化学吸附的多分子层吸附这一假设。三种天然染料在阳离子化改性棉纤维上的吸附基本符合Langlnuir吸附模型,也在一定程度上符合Freundlich吸附模型。即三种天然染料在改性棉纤维上的吸附,除了定位吸附外,还存在着非定位吸附。更多还原

【Abstract】 Natural dyes, derived from nature, are biodegradable, and compatibile with eco-environment. They are harmless to human health and consistent with the demands for health and environmental protection. However, most natural dyes show the problems of low dye-uptake and poor colorfastness on cotton. In order to solve those problems, cationic modifications of cotton were studied and applied in the dyeing with natural dyes, leading to a significant improvement in the dyeing performance. In this paper, the reactive modifier H and non-reactive modifier BE-2 were used to modify cotton fabrics. The modifying process and dyeing process of natural dyes were optimized, and the dye-uptake increased remarkably. The stability of natural dyestuffs was studied by UV-Visible spectroscopy, and the thermal analysis and Zeta potential analysis. The physical and mechanical properties of cotton before and after modification such as whiteness, strength, moisture content and moisture regain were investigated. Adsorption isothermals and dyeing rate curves were made to study the thermodynamics and kinetics properties of natural dyes on the modified cotton.The optimized modification process for the reactive modifier H was as follows: Firstly, 4% (o.w.f) modifier H and 0.5-1 % (o.w.f) peregal O were mixed together at room temperature with bath ratio 1:30 and the cotton fabrics were dipped in this solution. The above solution was heated up to 70℃and kept for 30 min. Then, 0.5-1 g/L NaOH was added into the solution to react with the cotton fabrics and modifier H for 20 min. Finally, the modified fabrics were washed with cold water. In addition, the optimized modification process for the non-reactive modifier BE-2 was as follows: cotton fabrics was dipped in 4 % (o.w.f) BE-2 solution at 70℃for 10-15 min with bath ratio 1: 30.The cotton fabrics modified by the above two processes exhibit positive Zeta potentials and slightly decreased thermal stability. However, the physical and mechanical properties show little changes. The dyed samples after modification have high color yield, good color fastness, levelness, as well as excellent UV-protection properties. In order to improve the theoretical guidance to process control and process optimization, the absorption kinetics and thermodynamics of the natural dyes on modified cotton were studied. Pseudo first- and second-order kinetic models were used to examine the adsorption kinetic data and some dyeing kinetic parameters were calculated. Furthermore, three theoretic adsorption models, Langmuir, Freundlich and Nernst isotherm, were used to simulate the thermodynamic experimental data and some dyeing thermodynamic parameters were also calculated. The results indicated that the adsorption kinetics of the three natural dyes on modified cotton fabrics was follow the pseudo second-order kinetic model, which means the adsorption of the natural dyes on modified cotton was chemical adsorption including multi-molecular layer adsorption. Batch isotherm studies showed that the adsorptions of these three natural dyes on modified cotton were described by the Langmuir and Freundlich isotherms. The adsorptions were not only specific site adsorption, but also non-specific site absorption.更多还原