A heterogeneous binary solvent system for recyclable reactive dyeing of cotton fabrics

作者:Zhao, Jiangbin; Agaba, Aphra; Sui, Xiaofeng*; Mao, Zhiping; Xu, Hong; Zhong, Yi; Zhang, Linping; Wang, Bijia*
来源:Cellulose, 2018, 25(12): 7381-7392.
DOI:10.1007/s10570-018-2069-8

摘要

Recyclable reactive dyeing of cotton fabrics was achieved in a heterogeneous non-aqueous binary solvent system. Ethyl octanoate (EO) and dimethyl sulfoxide (DMSO) were selected as exhaustion medium and solvating medium respectively. The solvents were immiscible at room temperature but formed a continuous phase upon heating and agitation, allowing for simple separation after dyeing. Sufficient swelling of the cotton fabric and excellent dye substantivity could be achieved by tuning ratio of the DMSO and EO. Compared with conventional aqueous dyeing, the solvent-based process required up to 40% less amount of dye and no inorganic salts. The dyeing sequence could be repeated 10 times. At the end of each dyeing cycle, 98.5v% each of EO and DMSO was recovered and reused. The process was generally applicable to commercial monochlorotriazine dyes with consistently good shade build-up and colorfastness. Therefore, the heterogeneous DMSO/EO dyeing system provides a promising solution to the environmental problems associated with reactive dyeing of cotton in a source-controlled manner.Graphical abstract [GRAPHICS] .