| The development of papermaking industry has being increasingly subjected to environment and resource. In the face of limited forest resources, the growing consumption of paper, and the enhancement of public awareness of environmental protection and so on, paper industry has focused on the problem how to make good use of available resources and clean to make pulp and paper. Bamboo has obvious superiority among the lignocellulosic resources in China. Better utilization of bamboo resources not only eases the demand pressure of wood fiber material in our country, but also gains the pulp with high-purity cellulose by optimizing process. According to the theory of environmentally friendly production and economy, the abundant bamboo in Jinghong in Yunnan province was used as the preparation of the pulp with high-purity cellulose, in this thesis. The emphasis of the research was put on kraft pulping at low temperature and ECF bleaching. It can provide theoretical principle for industry utilization.1. The results from analyses of chemical compositions and fiber morphology show that Huang bamboo and Long bamboo have high cellulose content over 51%, and the longest fiber length beyond 4 mm.2. Optimum conditions of kraft pulping of Huang bamboo and Tianlong bamboo are shown as below.(1) Optimal kraft pulping conditions for 2-years Huang bamboo:alkali charge 27%, sulfidity charge 5%, cooking complexed assistant charge 1.5%, Tmax 155℃, time to Tmax 150 min, time at Tmax 240 min.(2) Optimal kraft pulping conditions for 3-years Tianlong bamboo(b):alkali charge 27%, sulfidity charge 5%, cooking complexed assistant chargel.5%, Tmax 155℃, time to Tmax 150 min, time at Tmax 210 min.3. Optimal OD1EopD2 bleaching conditions for Huang bamboo and Tianlong bamboo kraft pulping:(1) Optimal OD1EopD2 bleaching conditions for Huang bamboo kraft pulping: Oxygen delignification (O), alkali charge 2.0%, MgSO4 usage 0.5%, Tmax90℃, time to Tmax 60 min, consistency 10%, initial pressure of oxygen 0.5 MPa; Chorine dioxide(D1), C1O2 charge 1.0%, Tmax70℃, time to Tmax 90 min, consistency 10%, bleaching pH3.5-4; Oxygen-Peroxide Extraction(Eop), H2O2 charge 1.0%, alkali charge 1.5%, Na2Si03 charge 1.5%, EDTA charge 0.5%, Tmax 95℃, time to Tmax 60min, consistency 10%, initial pressure of oxygen 0.5 MPa; Chorine dioxide (D2), C1O2 charge 0.3%, Tmax 70℃, time to Tmax 150 min, consistency 10%, bleaching pH3.5-4.(2) Optimal OD1EopD2 bleaching conditions for Tianlong bamboo kraft pulping: Oxygen delignification (O), alkali charge 2.0%, MgSO4 usage 0.5%, Tmax 90℃, time to Tmax 60 min, consistency 10%, initial pressure of oxygen 0.5 MPa; Chorine dioxide(D1), C1O2 charge 1.0%, Tmax 70℃, time to Tmax 90 min, consistency 10%, bleaching pH3.5-4; Oxygen-Peroxide Extraction(Eop), H2O2 charge1.0%, alkali charge 1.5%, Na2Si03 charge 1.5%, EDTA charge 0.5%, Tmax 95℃, time to Tmax 60 min, consistency 10%, initial pressure of oxygen 0.5 MPa; Chorine dioxide(D2), C1O2 charge 0.3%, Tmax 70℃, time to Tmax 150 min, consistency 10%, bleaching pH3.5-4.4. Huang bamboo and Tianlong bamboo high-purity cellulose pulp were measured. Bleaching pulp with a-cellulose content beyond 96% could be gained from Huang bamboo and Tianlong bamboo, but their ash content and iron contents are still high.5. The evaluation results of the original bleaching pulp and their acetylized products from Huang bamboo and Tianlong bamboo showed that the degree of esterification of these cellulose acetates were between 2-3, and the crystallinity of acytylized products were largely lowered.6. The results of IR,1H-NMR,13C-NMR are shown that the lignin structure from Huang banboo and Tianlong bamboo are composed of the guaiacyl units, syringyl units, and p-hydroxyphenyl units, especially, the guaiacyl units are major. Kraft pulping resulted in significant breakage ofβ-O-4 linkage in lignin structure, which brought about the degradation and dissolution of lignin macromolecules, and the resilual lignin in pulp seems to contain somewhat obvious condensation structure forms. |
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