Synthesis And Its Applied Research As Green Adhesive For Cellulose Sulfate

Cellulose is the most widely distributed in nature, the most abundant biomass-based polymers, about200billion tons of cellulose produced by natural photosynthesis annually, accounting for over50%of the carbon content of the plant kingdom, is inexhaustible and endless natural renewable resources. Cellulose sulfate ester is a product that hydroxyl group of cellulose binding with sulfur molecule, and cellulose sulfate ester salt is stable after neutralized, have good film-forming and bonding properties, and cellulose sulfate ester is also form soluble complexes with monovalent. divalent, and trivalent metal ion. Therefore, cellulose sulfate is a water-soluble cellulose derivative that the most potential to development. However, due to the existing cellulose sulfate synthesis methods require extensive use of protic solvents and acid-binding agent, product quality is unstable, difficult to separate and recover, higher cost of production technology and economic bottlenecks, resulting cellulose sulfate has no industrial products, so the most promising products fail to practical applications. In this thesis, hope these findings will help to break impasse:(1) SO3/DCE sulfated system that the newly discovered by our research group used to sulfonate cellulose or straw powder and conducted in-depth technology package applied research and product development. By optimizing the reaction conditions, such as:drying temperature and time of the material, the reaction time, reaction temperature, the amount of alkali, with a ratio of SO3, etc., to ensure product performance and easily implement, a lot of application research were conducted to product performance and use of results. Successfully prepared a few kilograms of cellulose sulfate products with excellent performance on our platform sulfonated biomass pilot, demonstrated that the feasibility of the process of industrialization. While various characterization and analysis were usded to test products, such as:13C NMR, IR. SEM, XRD, TGA, DS, Mw and so on.(2) Based on the new technology product obtained as a key characteristic of the adhesive research, a lot of research conducted on small scale and pilot products, such as, water-soluble, alcohol-soluble, film-forming, and the solution viscosity of characteristic and compatibility with metal salt, the products demonstrated have good solubility, the concentration of the aqueous solution can reach more than60%, when the solution concentration of more than20%exhibit colloidal properties and have a good polymer performance, It can be formed film with excellent performance, crystal clear, uniform texture and green compliant, It found that carboxymethyl chitosan, sodium silicate, ferrous sulfate and other organic and inorganic polymer or an inorganic salt was added to the product solution can significantly improve the viscosity characteristics.(3) Green adhesives series formula optimization and product development have made important breakthroughs. Comparative study of tensile shear strength have found that the NaCS of small or pilot trial products, UF and PVA solution on wooden, metal and glass:Cellulose sulfate ester salt products have good adhesive properties with wooden, metal and glass. In case of equal amounts of glue, the range of cellulose sulfate products and UF with the same adhesive strength, both of which are much stronger than the adhesive strength of polyvinyl alcohol. In addition, zinc, magnesium and carboxymethyl chitosan join with cellulose sulfate salt can significantly improve the bond strength.(4) UF and other formaldehyde adhesives still being widely used due to low prices, bond ability, fast curing time, simple sizing process, But because the long-term release formaldehyde pollution hazards to human health and living environment has aroused a high degree of vigilance, the social hope that glue with cheap and green. The cost of production of cellulose sulfate ester salt products can be less than2000yuan/t, the production cost is only half or a third of the urea-formaldehyde resins. Therefore, cellulose sulfonate products on three maior concerns have absolute advantage to replace the existing water-soluble urea-formaldehyde resin adhesives, such as, environmental health, adhesive properties and production costs, it can develop a new series of adhesive product with green, healthy, non-toxic and water-soluble, it has not only a great application value, but also significantly social, economical and environmental efficiency.