METHOD FOR PRODUCING SYNTHETIC CELLULOSE Russian patent published in 2018 - IPC C08B15/00 

FIELD: pulp industry.

SUBSTANCE: invention relates to methods for producing synthetic cellulose by polymerizing an aqueous solution of glucose. Cellulose is obtained by electroporation from an aqueous solution of glucose in the presence of a heteropoly acid of 1–12 series as a catalytically active substance. Method is carried out as following. As a reagent, 20–40 % by weight of an aqueous glucose solution produced by dissolving crystalline glucose in distilled water is used. Then, a tungsten-vanadium heteropoly acid of 1–12 series having a chemical formula H₆[PW₁₀V₂O₄₀], stable in aqueous solutions and having catalytic activity due to a reversible change in the degree of oxidation of the anionic complex is added to the solution. For 1 liter of the prepared aqueous glucose solution add from 1 to 10 g of pure heteropoly acid having the formula H₆[PW₁₀V₂O₄₀]. After complete dissolution of the heteropoly acid, the solution is thermostated in the temperature range from 25 to 35 °C and at a flow rate of 0.1 to 7 ml per minute are fed into the graphite tube 2 (see Fig. 1), which can have an internal diameter of 2 to 15 mm and around which an electrical insulation 3 is made, not allowing electrical contact with the outside of the graphite tube, and the graphite tube itself is lowered into dielectric galvanic bath 1, on the opposite side of which is placed counter electrode 4, which in turn can be made of graphite, stainless steel or nickel. Graphite tube is electrically connected to DC voltage source 5 such that the graphite tube is an anode and the counter electrode is a cathode. To monitor the current strength in the electrical circuit, ammeter 6 is sequentially included. Prepared thermostated aqueous solution of glucose with the addition of a heteropoly acid is fed through flexible tube 7 which is connected to a graphite tube, whereby the solution starts to flow into the plating bath, gradually filling it. As soon as the solution level reaches the level of the lowered electrodes, the electric circuit closes. Then, in a cyclic mode, a voltage source is applied to the anode and the cathode is applied to the voltage in the following order. First, within one minute, the voltage is raised from 0 V to 27 V, then for 2 minutes it is smoothly lowered to 5 V and again raised for 1 min to 27 V. Number of cycles depends on the required amount of cellulose to be produced. As a result of this cycling on the anode, which is a graphite tube, the formation of white flocs 8 begins, which form an insoluble slurry in the solution. After that, they can be taken out of solution for subsequent operations with them.

EFFECT: invention can be used to produce high purity cellulose, and this method in the future can form the basis of a new industrial technology for the production of synthetic cellulose without the use of natural wood and without the use of natural cotton.

1 cl, 4 dwg, 1 tbl