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Traditional poplar APMP pulping raw material alkaline H2O2 pretreatment require alkaline conditions are generally provided by the added NaOH, of NaOH strong alkaline easily cause partial degradation of the carbohydrates, reducing amazing rate, degradation products into the waste increase the pretreatment effluent COD content, increasing the pollution load, and the Mg (OH) 2 a weakly basic, can make up the above-mentioned drawbacks of the sodium alkali, thus using Mg (OH) 2 by poplar APMP Pulp Technology attention. This thesis Mg (OH) 2 Poplar APMP pulping and Mechanistic Studies alkali source or alkali source, including pretreatment of the single-stage and two-stage pretreatment pulping process and the poplar single-stage pretreatment ferrierite parameters of APMP pulping process. While taking advantage of the the FQA, ESEM, XPS analysis means ferrierite poplar APMP pulp fiber characteristics. First, ferrierite as the alkali source, poplar single segment pretreatment APMP pulping more suitable chemical pretreatment conditions: H2O2 :5.0-6 .0%, Mg (OH) 2:4.35% of Na2SiO3: 4.0%, EDTA, : 0.5%, liquid ratio: 4:1, reaction temperature of 70-80 ° C, the reaction time of 90 min. Under the process conditions, when the freeness 450SR, whiteness can be obtained for 67.5-68.4% ISO, opacity of 91.1%, light scattering coefficient of 47.65 m2 · kg-1 of the slurry, but the strength of the pulp is poor, only 1.32 km, breaking length and tear index of only 1.63 mN · m2 g-1. Secondly, to replace some or all of the magnesium hydroxide of sodium hydroxide, the poplar APMP pulping study and found that, with the Mg (OH) 2 substituted increase in the amount of NaOH, the decline in physical strength and whiteness of paper, but does not transparency, bulk and light scattering coefficient improved. Ferrierite partial substitution of a single segment of Poplar APMP of the optimal conditions: Mg (OH) 2 to replace the amount of 50% H2O2: 5.0% Na2SiO3: 4.0% EDTA: 0.5%, liquid ratio: 4:1 , reaction time 80 min; of two sections poplar APMP pulping and preferred process conditions: The first full with sodium hydroxide, and the second paragraph of Mg (OH) 2 was 50% substituted. Can be obtained under the conditions of the process, the whiteness of 71.9% ISO, breaking length was 3.76 km, tear index 4.53 mN m2 g-1, the opacity of 83.3%, light scattering coefficient of 42.52 m2 · kg-1 slurry. At the same time, the poplar APMP of the Mg (OH) 2 can effectively reduce the the wastewater COD content. Magnesium hydroxide to replace the amount of increase in the pulping liquor COD decreased, which is more conducive to the realization of clean production. In the case of the same amount of OH-, with the magnesium hydroxide replaced increase in the amount of lignin in the pulp, carbohydrates, and organic solvent extraction was dissolution rate decreased. Again, through the observation of the mass analysis of the pulp fibers and pulp fibers scanning electron microscopy topography and found that, with increasing Mg (OH) 2 to replace the amount of the resulting pulp fibers have a length weighted average length becomes shorter gradually, whether number average fine fiber content or the content of length weighted average performance with the increase in the Mg (OH) 2 substituted amount gradually increases. Poplar APMP substituted by different ferrierite pulp fiber surface XPS analysis showed that, with the magnesium hydroxide to replace the amount of increase, C1s combination can be decreased, the C1s peak area increases, O1S peak area is reduced, i.e. O / C than reducing described, ferrierite poplar APMP the surface of the pulp fibers increase in lignin content, reduce carbohydrate content; simultaneously analyzed by XPS before and after the acetone extraction of pulp fibers contrast, acetone extraction after the O / C ratio increases, reducing The content of the lignin of the surface of the fiber and other hydrophobic substances. The following: ① the poor weak alkaline and Mg2 adsorbed on the fiber surface, so that the degree of swelling of the fibers Ferrierite fiber pliability decline mainly due to the poor performance of its strength magnesium alkali APMP slurry, thereby refining process, the fibers are cut more, the average fiber length is shorter, a higher content of fine fiber; ② ferrierite weakly alkaline such that less fiber surface lignin dissolution Moreover, the hydrophobic substance content of the surface of the fiber is increased, hindering fiber with the connection between the fiber and combined.
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