Cleaner dyeing of silk with reactive dyes plus molecular companions

Organic small molecule cations were used as molecular companions of reactive dyes,and dyeing of silk with reactive dyes using molecular companions as accelerator was studied.The results showed that organic small molecule cations had wonderful dyeing acceleration effect.Greater the hydrophobic of the cations,higher the dyeing acceleration rate.If the carbon atom number of hydrophobic hydrocarbon chain of cations was equal to or greater than 12,they would hinder the color fixation of reactive dyes.On the contrary,if it was equal to or smaller than 8,the color fixation reaction would not be affected.In the dyeing process,if organic small molecule cations were added in several times,the silk could be dyed uniformly.If higher hydrophobicity is desired,for meeting the requirement on the carbon atom number of hydrophobic hydrocarbon chain of cations equal to or smaller than 8,the hydrophobic part can be designed on the two hydrocarbon chains.When octyl trimethyl ammonium bromide(OTAB) and dihexyl dimethyl ammonium bromide(DHDAB) were used as accelerants in low concentrations for dyeing silk with reactive dyes,high color fixation rate was yielded,and the chrominance of the dye wastewater was low.So,OTAB and DHDAB are cleaner dyeing agents that have very good potential applications.