The Artificial Pulp Made From Reed By Pre-hydrolysis Kraft Process

Originally，the main material of artificial fiber pulp was natural fiber from wood andlinters etc. However, it will face more and more difficult to make this pulp owing to scarcityof forest resource and cotton field in our country. While reed distributes widely and yieldhighly in China, it will be significant to use reed to produce artificial fiber pulp.First the key exploration of this paper was to prepare high quality reed pulp by cookingand bleaching processes. Then the main process was optimized and got the optimumparameters.（1） The optimum conditions of prehydrolysis by water: liquid ratio1:6, the highesttemperature175℃, holding time75min. Among them highest temperature andholding time have more effect on prehydrolysis.（2） The best technical parameters of sulfate cooking: alkali charge18%（o.d. pulp, onNa₂O）, sulfidity19%（o.d. pulp, on Na₂O）,75min.（3） ECF bleaching process used D1-Ep-D2-A, yielded the optimum process condition ofD stage: ultima pH4,70℃,120min, total chlorine charges2%. The property ofbleached reed pulp was that the brightness was85.5%ISO, the degree ofpolymerization was636mL·g^-1, α-cellulose was95.7%, pentosan content was1.93%,ash was0.10%and iron content was18.5mg kg-1. TCF bleaching processes usedOp-PAC-Q-P-A, the optimum conditions of PAC （peracetic acid） stage: initial pH7,70℃,60min, PAC dosage2%. The property of reed pulp bleached by TCF: thebrightness86.6%ISO, the degree of polymerization581mL·g^-1, α-cellulose96%,pentosan content2.01%, ash0.06%, iron content10.4mg kg^-1, at the same time,pulp got through the reaction performance tests of pulp.In addition, hemicellulose isolated from waste liquor of reed prehydrolysis also wasexplored in this paper. Cationized hemicellulose with different substitution degree was madeby etherification. Effect of cationic hemicellulose agent, catalyst NaOH, reaction time andtemperature on the substitution degree was mainly discussed in this paper. The results showedthat when the mass ratio of the cationic hemicellulose agent to hemicellulose was0.8, that ofNaOH to hemicellulose was0.08,2h,60℃, the substitution degree of cationic hemicellulose was0.0217. The IR results characterized that there were cationic groups in structure ofmodified hemicellulose. In addition, papermaking experiment showed that cationic modifiedhemicellulose had significantly reinforced effect on pulp.