Vietnamese Sweet-Bamboo Chemical Properties And Pulp Making Research

Vietnamese sweet bamboo shoots are a production of high quality, they distribution mainly in the north-west, coastal central and southern highland areas in Vietnam; but on a detailed study and use of sweet bamboo less than many in Vietnam, this thesis will be Vietnamese sweet bamboo to conduct in-depth research and analysis and comparison with other paper-making raw materials, following main conclusions:From chemical composition analysis of raw materials: 1%NaOH extract content is 25.73%, ash content of raw materials for 1.94%, monocellulose content is 75.34%, lignin content is 25.24%; Cooking process conditions suitable for: alkali dosage 22%, maximum temperature 1700C, holding time 120min, obtained pulp yield for 38.21%, Kappa 18.55, whiteness 25.25%ISO; Bleaching process conditions suitable for ClO2 dosage is 3.0% in section D, H2O2 dosage is 1.0% in section E, H2O2 dosage is 3.0% in section P. Under the best conditions for bleaching, bleaching results are whiteness is 79.11%ISO,PC value is 3.2. Cooking at the reaction mechanism of studies have shown that: Lignin removal can be divided into three stages were: the initial delignification stage (warming to1700C), lignin removal rate is 75.35%; substantial delignification stage (Insulation 1.5h in 1700C), lignin removal rate is 96.71%; residual lignin removal stage (Insulation 2.5h in 1700C), lignin removal rate is 98.18%. Study the molecular weight of lignin indicated that, raw materials mainly concentrated in the molecular weight of less than 4000(accounted for 50.5%),from 4000-8000 accounted for 24.6 percent, from 8000-16000 accounted for 20.2 percent, while only a small amount of more than 16000; Sweet bamboo whole pulp part of 4000 following 20.3%, the 8000-16000 part from 20.2% ( raw materials) rosed to 33.1%( whole pulp) , increase of 38.9%, the more than 16000 part so from 4.7% (raw materials) rosed to 16.1% (whole pulp), increase of 70.8%. Cooking at the course functional groups of residual lignin changes, methoxyl content decreased, from 15.42% (raw materials) dropped to 12.35% (whole pulp), the phenolic hydroxyl group content and carboxyl content has increased, from 2.08% (raw materials) rosed to 3.17% (whole pulp), carboxyl content from 5.36% (raw materials) rosed to 5.99% (whole pulp). Vietnamese sweet bamboo average length of fiber (raw materials) is 2.37mm, greater than Bambusa textilis and Dendrocalamopsis, in accordance with the provisions of the International Association of wood anatomy, Vietnamese sweet bamboo belong to long-fiber raw materials. Fiber wall thickness is 8.13μm, fiber wall–cavity rate for the 6.33, greater than Bambusa textilis and Dendrocalamopsis.