| As a new kind of broad-leaf fast-wood Populus×euramericana cv. '74/76' has the advantage of growing fast, good ability of anti-cold and anti-plant diseases. It has good wood properties.So it is a kind of material which can be used for pulping and paper making.But there is few reseach about it in the field of pulping and papermaking. The main idea of this passage is the infection of the different soils on longitudinal variation of chemical compositions,fiber form ,ASAM pulping capability and the technics of bleaching on Populus×euramericana cv. '74/76'.In the ASAM pulping techincs ,it has a contrast about the effects between Super dispersing Anthraquinone and Common crystal Anthraquinone.Populus×euramericana cv. '74/76' has good fiber length and length-width ratio: the length of fibers is 1.03 and 1.27mm ,and the length-width ratio is 46 and 52. Black alkali soil Populus×euramericana cv. '74/76' has less size in length,width and length-width ratio compared to sandy soils Populus×euramericana cv.'74/76'.Both are suitable for pulping and paper making.The alcohol-benzene extract content of Populus×euramericana cv. '74/76 'is 2.44% and 3.91%,the lignin content is 22.52% and 23.00%,the cellulose content is 50.25% and 49.50%,the semicellulose content is 20.45% and 19.54%.According to the experiment result of the chemical consistent,the Populus×euramericana cv. '74/76' is fit to be the material of pulping and paper making. Black alkali soil Populus×euramericana cv. '74/76' is better than sandy soils Populus×euramericana cv. '74/76'.The optimized condition of Black alkali soil Populus×euramericana cv.'74/76' for ASAM cooking is:sodium hydroxide dosage 10%-11%,sodium sulfite dosage 18%-20%,Super dispersing Anthraquinone dosage 0.06%,carbinol dosage 16%-18%, the first cooking time 90-110min.The optimized condition of sandy soils Populus×euramericana cv. '74/76' for ASAM cooking is: sodium hydroxide dosage 9%-11%, sodium sulfite dosage 18%-20%, Super dispersing Anthraquinone dosage 0.06%, carbinol dosage 16%-18%, the first cooking time 100-110min.The other conditions are the same:liquor ratio 1:5.5,the highest temperature 165℃ .The first time keep the temperature rising to 140℃ and keep 140℃ 90min,then spend 50min to rise the temperature to 165℃ and keep 165℃ 60min.The yield of screened pulp is more than 50%,the kappa is low and the whiteness is high. We could get stuff that more than 90%ISO by bleaching,what is more ,it has high viscosity,and the viscosity decline litte when bleach it. So it could has good ability of physical property.The bleaching stock of Populus×euramericana cv.'74/76' has tensile strength,its tensile indes can reach more than 86 N.m.g-1,and other physical property are a little worse.Compare the effect of the pulping between cooking accelerant of Super dispersing Anthraquinone and Common crystal Anthraquinone on Black alkali soil Populus×euramericana '74/76'.The result shows that Super dispersing Anthraquinone which can dissolve in water and alkali easily mixes with materials equably.It has more advantages.In the DEpD bleaching process ,we could get better bleaching effection if we use magnesium hydrate replacing magnesium sulfate and remove all sodium hydroxide. We can get a result of high whiteness,viscosity declining less.Compared with only using sodium hydroxide and magnesium sulfate, magnesium hydrate does good to release cellulose retrogradation,and increase the whiteness and viscosity after bleaching.In the foundation of the research about the fiber form and the chemical compositions of Populus×euramericana cv.'74/76',v/e emphasized in the pulping and bleaching craft.Totally,Populus×euramericana cv.'74/76' is a good kind of material for paper making. Black alkali soil Populus×euramericana cv. '74/76' is a little better than sandy soils Populus×euramericana cv. '74/76',and both are fit to the method of ASAM.
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