Research On Cellulose Etherifying Modification And Application Of Reactive Dye Printing Paste

Since the advent of reactive dyes in the last century, sodium alginate (SA) has been themain reactive dyes printing paste. However, along with the higher expectation of the fabricprinting quality, Sodium alginate, as a printing paste, has exposed some flaws in the flat screenand rotary screen printing, owing to its low resistance to strong acid and strong alkali, as wellas its low structural viscosity. Moreover, in recent years, the price of sodium alginate has beenincreasing continuously. Therefore, researchers have begun the explorations on its substitutes,one important example of which is the Cellulose ether. However, at present the main rawmaterial used in the preparation of cellulose ether is cotton, the yields of which are decreasingand the price of which is increasing. Additionally, the commonly used etherifying agent, such aschloroacetic acid (poisonous), epoxy ethane (carcinogenic), etc., can harm human body and theenvironment greatly. Hence, this research extracted cellulose from plant wastes, used sodiumchloroacetate and2-chlorohydrin as etherifying agent, and prepared three kinds of celluloseethers: carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC) and hydroxyethylcarboxymethyl cellulose (HECMC). The research then applied the three kinds of cellulose ethersand SA respectively to reactive dyes printing and compared the printing results from using thesethree kinds of cellulose ethers as well as SA. The main research content of the paper consists ofthree parts.（1）extracting cellulose from plant wastes. Through measuring and analyzing eachcomponent (moisture, ash, lignin, cellulose and hemicellulose) of five kinds of plant wastes (ricestraw, rice husk, wheat straw, pine sawdust and bagasse), three representative plant materials(pine sawdust, wheat straw and bagasse) were selected to extract cellulose, and celluloseextraction process was optimized. Under the optimized condition, pine cellulose, wheat strawcellulose and bagasse cellulose were obtained, the relative purity of which was above90%andthe production rate of which was more than40%. In addition, analysis of IR and UV absorptionspectrum showed that impurities lignin and hemicellulose were substantially removed, obtainingthe high purity of cellulose. Meanwhile, compared with the plant materials, the X-ray diffraction analysis showed thatthe crystallinity of the obtained cellulose was greatly improved.（2）The preparation and characterization of cellulose ether. Using extracted pine celluloseas raw material, by the means of single-factor experiments, decrystallization pretreatmentprocess with concentrated alkaline of pine cellulose was optimized. Through orthogonalexperiments and single-factor experiments, the preparation process of CMC, HEC and HECMCwith alkalined pine cellulose was optimized. In each optimal preparation conditions, CMC withDS up to1.237, HEC with MS up to1.657and HECMC with DS of0.869were obtained.Through the FTIR and H-NMR analysis, the three kinds of cellulose ethers have introduced thecorresponding ether group successfully. The XRD analysis showed that the crystallographicforms of cellulose ethers CMC, HEC and HECMC were all transferred to celluloseⅡtype, withthe degree of crystallinity significantly reduced.（3）The application of cellulose ether paste. Using the three optimally prepared celluloseethers, the reactive printing effects were evaluated and compared to that of SA. The resultsshowed that the four kinds of original paste-SA, CMC, HEC and HECMC–all belong topseudoplastic fluid and that the pseudoplastic performance of the other three kinds of celluloseether was better than SA. The pasting abilities of the four kinds of paste is as follows: SA>CMC> HECMC> HEC. As for the printing effects, apparent color yield property, permeability,printed feeling, fastness of pigment printing of CMC were all similar to those of SA, and the breiremoving rate of CMC original paste is better than that of SA. Brei removing rate and printedfeeling of HEC were similar to those of SA, but its apparent color yield, permeability and colorfastness to rubbing were worse than those of SA. The printed feeling, color fastness to rubbing ofHECMC were similar to those of SA, and its brei removing rate was higher than that of SA; butapparent color yield and storage stability of HECMC are worse than those of SA.