Isolation, Analysis And Membrane Formation Mechanism Of Cane Marrow Parenchyma Cells

The lack of wood resources has become a bottleneck for the sustainable development of papermaking industry in China.Reasonable development and utilization of non-wood fibers,especially for easy attainment of massive low-price crop straws,is considered as important complimentary resource for paper industry.Meanwhile,it will be of great importance to both the advancement of straw papermaking and the commercialization of valuable products derived from non-fibrous cells,if parenchyma cells deemed "useless and even handicap" can be reasonably utilization,This thesis,as a part of the project "Study on separation and characterization of parenchymas from straws and their film-forming mechanism",addressed chemical pulping of bagasse pith for parenchymas and fibers as well.The chemical composition,surface structure etc.of the parenchymas were revealed by relevant analyses,then formation of the film from parenchymas was investigated,also the film was characterized for its surface and strength properties.1.Comparative studies of soda-AQ,alkali-oxygen and alkaline sulfite pulping of bagasse pith have revealed that the results from ASP were ideal.The parenchymas with 11.3%yield,5.2 Kappa number,54%ISO whiteness and 678 mL/g as well as fibers with 48%yield were obtained,under the condition:22%(75%sodium sulfite),AQ 0.1%,liquid ratio 1:6,temperature 160? for 90 min.2.Analysis of the chemical composition of fibers and parenchymas obtained from different pulping processes,manifested that the lignin and the pentose content were close to each other,being 1-2%and 27%,respectively,and the cellulose content of parenchymas was 5-10%less than its fibers.3.A further comparison of other characters between them showed that the lengths of fibers and parenchymas were 0.9-1.0 mm and 0.3-0.4 mm,respectively,and the drainage of parenchymas was far inferior to that of its fibers.4.The film down to 10 g/m2 grammage can be prepared from parenchymas by sheet formation.There were significant differences in physical properties and structure between parenchymas before and after film formation.Deflaking without destruction of parenchymas administered to the uniformity of the film,outstanding improvement of its specific surface area,smooth compact bonding of parenchymas.5.By means of SEM,AFM,XRD,IR,and XPS,characterization of parenchymas and their forming films helped us to understand their elementary properties,provided us with a sound theoretic basis of parenchyma-film preparation technical system.