Preparation Of Carboxymethyl Cassia Seed Gum And Its Application In The Reactive Dye Printing

Sodium alginate with its excellent performance has been used as a reactive dye printing thickener.In recent years,due to the increase in market demand,and the country's emphasis on environmental protection,new printing pastes are urgently needed to replace the sodium alginate.Because of Rich in natural resources,ecological and environmental protection,low price,good rheological and physical and chemical properties,carboxymethyl cassia seed gum(CM-CTG)belonging to the anionic polysaccharide derivatives,can be used as a reactive dye printing thickener.In this paper,high degree of substitution of CM-CTG was synthesized with solvent method.The influence of etherification temperature,alkalization and etherification time,sodium hydroxide to monochloroacetic acid(MCA)molar ratio(nNa OH/nMCA),theoretical degree of substitution(DSt),ratio of water and liquid on degree of substitution(DSt)and reaction efficiency(RE)of CM-CTG were investigated,before and after the reaction of cassia seed gum for structural were investigated and analyzed,the physicochemical properties of different substituted CM-CTG were studied,and different substituted CM-CTG were used as the reactive dye printing paste and printing effect were investigated.The results showed that the DS and RE of CMCTG had the same change trend and went through a maximum with the increase of reaction temperature,NaOH and MCA molar ratio increases,the increase of water content in reaction system.As the extension of reaction time and the etherification time,DS and RE of CM-CTG were gradually increasing then tended to a stable value.With the increase of theory degree(DSt),DS went through a maximum,but RE had been the trend of decrease.The optimum reaction conditions are as followed: reaction temperature is 68?,reaction time is 60 min,etherification time is 180 min,n(NaOH)/n(MCA)is 2.1:1,DSt is 1.5,m(H2O)/m(dispersant)is 20%.Structure tests showed that –COO-was introduced into the macromolecular chain,and to a certain extent,affected the super molecular structure of the polysaccharide.The results of physicochemical properties of different substituted CM-CTG showed that PVI values,network permeability and ability to resist shear sensitivity are increased and structureviscosities and cold water insoluble are decreased with increasing of DS of CM-CTG.water retention present a tendency of rising after the first reduce with increasing of DS of CM-CTG.salt resistance,resistance to acid and alkali stability are significantly increased with increasing of DS of CM-CTG.High degree of substitution of CM-CTG have better compatibility with auxiliaries(urea,sodium carbonate).The results of printing properties of different substituted CM-CTG showed that the removal rate of the pastes and colour yields were increased and feel of printed fabrics were improved with increasing of DS of CM-CTG and colour yield of printed fabric using high degree of substitution of CM-CTG(DS>1.0)as printing pastes was obviously higher than that of sodium alginate.