Eco-Friendly Dyeing of Pretreated Cotton Fabric Using a Natural Dye Extract from Erythrina abyssinica

ABSTRACT

The increasing awareness of toxicity of synthetic dyes has considerably raised the demand for natural dyes. Retaining color fastness and strength of natural dyes on fabric is the main limitation in textile dyeing with natural dyes. In this study cotton fabric was pre-treated with aqueous tannic acid in order to enhance the fabric’s color fastness and strength of the natural dye. The untreated, treated and dyed cotton were characterized using Fourier-Transform Infrared spectroscopic analysis to confirm the modification of the cellulosic fiber. Different solvents were used to extract dye from Erythrina abyssinica plant and subjected to phytochemical quantification then used to dye cotton. The new FTIR peaks at 2646 cm⁻¹and 1578 cm⁻¹, which correspond to carbonyl (C=O) stretching mode and C=C stretching mode for aromatic ring, respectively, confirmed the modification and dyeing due to the attachment of the aromatic dye molecules to the cellulose structure. It was noted that modification of cellulose structure enhanced color strength and fastness. Mordanting with alum and ferrous sulfate using different methods formed variety of shades that ranged between light yellow to greenish yellow. Therefore, Erythrina abyssinica plant can be used as a source of natural dye for dyeing cotton fabric.

摘要

人们对合成染料毒性的认识日益提高,这大大提高了对天然染料的需求. 天然染料在织物上保留色牢度和强度是天然染料染色的主要限制因素. 本研究采用单宁酸水溶液对棉织物进行预处理,以提高天然染料的染色牢度和强度. 利用傅里叶变换红外光谱分析对未经处理、处理和染色的棉进行了表征,以确认纤维素纤维的改性. 用不同的溶剂从刺桐植物中提取染料,进行植物化学定量,然后用于棉花染色. 2646cm-1和1578cm-1处的新FTIR峰分别对应于芳环的羰基(C=O)拉伸模式和C=C拉伸模式,证实了由于芳香染料分子附着在纤维素结构上而进行的改性和染色. 有人指出,纤维素结构的改性提高了颜色强度和牢度. 用明矾和硫酸亚铁采用不同的方法进行媒染,可形成从浅黄色到绿黄色的各种色调. 因此,刺桐属植物可作为棉织物染色的天然染料来源.

KEYWORDS:

• Natural dye
• pre-treatment
• tannic acid
• mordanting
• fastness
• color strength

关键词:

• 天然染料
• 预处理
• 单宁酸
• 媒染
• 牢度
• 色强度

Acknowledgments

This research was supported by Africa Centre of Excellence in Phytochemicals, Textile and Renewable Energy (ACE-PTRE) of which we are highly appreciative. Appreciation also goes to the School of Sciences and Aerospace Studies, Department of Chemistry and Biochemistry of Moi University.

Disclosure statement

The authors declare that there is no conflict of interest regarding the publication of this paper.

Ethics approval and consent to participate

Not applicable.