Study On Preparation, Application In Dyeing Of High Degree Carboxymethyl Starch Sodium

It is studied in this thesis how to prepare high degree of substitution carboxymethylstarch（CMS）. The high degree of substitution CMS’s properties and applications in printingpaste are also researched in this paper.Firstly, the process conditions of the high degree of CMS prepared by drum drier werestudied. By single factor experiment, that the effect of the alkalization process and theetherification process on the degree of substitution（DS）and viscosity was studied.Accordingto the results of single factor experiment, response surface test was designed and the optimumprocess conditions of high degree of CMS prepared by drum drier were determined: starchconcentration25%; nchloroactic acid:nNa2co3=1.21:1; nalkali amount:nAGU=2.26:1, nNaOH:nAGU=1.3:1,nNa2co3:nAGU=0.96:1; alkalization temperature35℃, alkalization time30min; etherifytemperature50℃, etherify time2.5h; drum speed400r/min, steam pressure0.53MPa;adding4.03%（total dry starch） of ammonium chloride catalyst on the alkalization process.The DS of ether in the product is about1.468, RE is70.81%.Secondly, that the properties of the high degree of CMS such as viscosity, ability,freeze-thaw stability and rheology was studied.At the same time, the group structure,crystalstructure and molecular weight distribution respectively were detected with FTIR, XRD andUbbelohde viscosity meter. It is showed that:-OH of corn starch was linked up with–CH₂COONa during reaction, crystal structure was destructed and molecular weight reduced.The high degree of CMS starch prepared by drum drier has good rheology and the viscosity isbigger.Lastly, the applications of samples in printing paste were investigated. DS is1.173and0.9876high degree （high viscosity） of CMS using in printing paste; the CMS/SA of85/15andthe SA of100%is about consistent on PVI、 hoiding water、 thixotropy、 chemicalcompatibility、colour yield、taking off the paste rate and printing color fastness. So CMS/SAof85/15can replace SA of100%to print fine decorative pattern.