Bamboo reed raw material biological fermentation cellulose pulping method and application thereof

Abstract

The invention relates to the technical field of pulping, in particular to a bamboo reed raw material biological fermentation cellulose pulping method and application thereof. Bacillus licheniformis, bacillus subtilis, bacillus pumilus and bacillus cereus are compounded into a complex microbial inoculant, the fermented bamboo reed raw material is used for pulping, all strains are mutualistic and synergistic, meanwhile, a rich complex enzyme system is provided, the prepared paper is good in physical performance and high in quality, pulping is conducted through biological treatment, and the paper is environmentally friendly and environmentally friendly. The use of a large amount of chemical agents in the traditional pulping is avoided, and the discharge of wastewater in the traditional pulping process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of pulping, and in particular to a method for pulping cellulose using biological fermentation of Phyllostachys australis raw materials and application thereof. Background Art

[0002] In the prior art, when pulping, most of the fibers are separated by strong alkali cooking, and washing is required before the subsequent process can be carried out. In addition, although most of the lignin has been removed from the raw materials in the cooking and separation process, there will still be about 3-12% of the lignin remaining, so there is still a need for a process of bleaching and washing the pulp. The prior art mostly uses chemical bleaching methods. The traditional chemical bleaching method uses multi-stage chlorine / chlorine dioxide bleaching and alkali extraction to remove lignin. Therefore, the existing papermaking technology has the following disadvantages: environmental pollution: a large amount of alkaline wastewater will be generated during the production process, causing serious environmental pollution such as water pollution and soil compaction; equipment corrosion: the strong acid and alkali used will corrode production equipment such as steaming balls; high energy consumption: due to the use of strong acid and alkali to treat the pulping raw materials and after the bleaching stage, a large amount of water is required for repeated washing, which consumes electricity and water; increased production costs: wastewater recycling treatment causes an increase in production costs; low utilization rate: the utilization rate of raw materials treated by the prior art is 40-45%. At present, in the pulping process, the existing technology has begun to apply biological fermentation to improve its pollution problem, but the existing biological fermentation papermaking method is usually an improvement on the chemical method and cannot completely eliminate the existing chemical pulping process. Therefore, there is still a lot of room for development in environmental protection, production efficiency and production cost. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a method for preparing cellulose pulp by biological fermentation of Phragmites australis raw material and application thereof.

[0004] The present invention is achieved through the following technical solutions: A method for preparing cellulose pulp from biological fermentation of Phragmites australis raw materials comprises the following steps: (1) cutting Phragmites australis into small segments of 4-6 cm, removing the outer epidermal branches and leaves and retaining the inner stems, spirally extruding at 700-800 r / min for 3-5 times, and air-drying to obtain Phragmites australis residue; (2) The activated Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus, and Bacillus cereus were inoculated into LB liquid culture medium at a volume ratio of 10%, and cultured at 30°C and 180 rpm for 24 h; (3) After culturing in step (2), a bacterial solution of Bacillus licheniformis, a bacterial solution of Bacillus subtilis, a bacterial solution of Bacillus pumilus, and a bacterial solution of Bacillus cereus are obtained respectively, and the obtained bacterial solutions are compounded and mixed to obtain a composite bacterial solution; (4) adding the Phragmites australis residue obtained in step (1) to LB liquid culture medium, preferably to completely soak the residue in LB liquid culture medium, then adding 10% of the volume of the composite bacterial solution of LB liquid culture medium, mixing well, and fermenting for 12 h; (5) After fermentation for 12 h in step (4), the modified polymer was added, stirred at 500-600 rpm for 2-3 h, and fermentation was continued for 36 h, filtered, washed, and refined with water in a mass ratio of 1:5. The refining gaps were 0.5 mm, 0.15 mm, and 0.08 mm, respectively. The pulp was heated at 60° C. for 20-30 min, and screened through a pulp screen with a gap of 1.5 mm for 15-20 min; (6) After the pulp is screened in step (5), papermaking is performed to make hand sheets, which are air-dried at 23°C. The paper weight is 80 g / m 2 .

[0005] Furthermore, in step (2), the Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus and Bacillus cereus are purchased from China General Microbiological Culture Collection Center, and the strain numbers are CGMCC 1.10314, CGMCC1.14985, CGMCC 1.10291 and CGMCC 1.10559, respectively.

[0006] Furthermore, in step (3), the number of viable bacteria in the composite bacterial solution is 1.0×10 11 cfu / mL, the ratio of the viable cell counts of Bacillus licheniformis, Bacillus subtilis, Bacillus brevis, and Bacillus cereus was 1:1:1:1:1:1.

[0007] Furthermore, in step (5), the mass ratio of the modified polymer to the Phragmites australis residue is 1:15-20 g.

[0008] Furthermore, the raw materials for preparing the modified polymer include the following components in parts by weight: 0.6-0.8 parts of methyl methacrylate, 0.5-0.7 parts of acrylic acid, 5-7 parts of butyl acrylate, 3-5 parts of styrene, 2-3 parts of modified oxygen-carrying microspheres, and 1-1.5 parts of modified talc.

[0009] Furthermore, the raw materials for preparing the modified oxygen-carrying microspheres include the following components in parts by weight: 1-1.5 parts of lecithin, 9-14 parts of perfluorotributylamine (PFTBA), 2-3 parts of allyltriethoxysilane, 2-3.2 parts of polylactic acid-glycolic acid copolymer (PLGA), 1-1.5 parts of polyvinyl alcohol, and 1.5-3 parts of sodium alginate.

[0010] Furthermore, the preparation of the modified oxygen-carrying microspheres comprises the following steps: A1: Add lecithin to PBS buffer at pH 7.4, perform ultrasonic emulsification at 450W for 3 times, each time for 20 s, with an interval of 45 s, add PFTBA, perform emulsification 10 times according to the above steps, place in a hyperbaric oxygen chamber for 15-20 min, filter through a 0.8μm filter membrane, and obtain PFTBA emulsion; A2: The PFTBA emulsion obtained in step A1 and PLGA were added to dichloromethane, and ultrasonic emulsification was performed at 300 W at 4°C for 25-35 s. A 1 vol% Tween 80 aqueous solution was added, and emulsification was performed at 200 W at 4°C for 30 s. -3 MPa, 400-500 rpm stirring for 3 h, washed with distilled water 3-5 times, centrifuged at 5000 rpm for 20-30 min, and the precipitate was freeze-dried at -40 °C to obtain PLGA microspheres; A3: Add polyvinyl alcohol and sodium alginate to deionized water and mix well, heat at 80-90°C for 20-30 min to obtain a polyvinyl alcohol / sodium alginate solution, add the PLGA microspheres obtained in step A2 to the polyvinyl alcohol / sodium alginate solution, stir at 200-300 rpm for 20-30 min, add dropwise to a 0.02 g / mL calcium chloride solution, stir at 200-300 rpm for 1-2 h, filter, wash the filter cake with deionized water, and vacuum dry at 40-50°C to obtain oxygen-carrying microspheres; A4: Add allyltriethoxysilane to tetrahydrofuran and mix well to obtain a silane solution. Add the oxygen-carrying microspheres obtained in step A3 to the silane solution, stir at 300-400 rpm for 4-5 h, centrifuge at 5000 rpm for 20-30 min, wash the precipitate with deionized water, and dry in vacuo at 60°C to obtain modified oxygen-carrying microspheres.

[0011] Furthermore, in step A1, the mass concentration of the lecithin in the PBS buffer is 0.1-0.15 g / mL.

[0012] Furthermore, in step A2, the mass concentration of the PLGA in dichloromethane is 40 mg / mL.

[0013] Furthermore, in step A2, the volume ratio of dichloromethane to Tween aqueous solution is 1:4-5.

[0014] Furthermore, in step A3, the mass concentration of the polyvinyl alcohol in deionized water is 0.04 g / mL.

[0015] Furthermore, in step A4, the mass concentration of allyltriethoxysilane in tetrahydrofuran is 0.05 g / mL.

[0016] Furthermore, the raw materials for preparing the modified talc powder include the following components in parts by weight: 2-3 parts of talc powder, 0.4-0.6 parts of dopamine hydrochloride, and 1-1.5 parts of undecylenic acid.

[0017] Furthermore, the preparation method of the modified talcum powder comprises the following steps: B1: dissolve dopamine hydrochloride in Tris-HCl buffer, add talcum powder, stir at 200-300 rpm for 1-1.5h, filter, wash the filter cake with deionized water, and dry at 80°C to obtain coated talcum powder; B2: Add undecylenic acid to toluene, add dicyclohexylcarbodiimide (DCC) and N-hydroxysuccinimide (NHS), stir at 200-300 rpm for 5-6 h, add the coated talc obtained in step B1, stir at 40-50°C and 200-300 rpm for 3-4 h, centrifuge at 5000 rpm for 20 min, wash the precipitate with deionized water, and dry in vacuo at 60-70°C to obtain modified talc.

[0018] Furthermore, in step B1, the mass concentration of dopamine hydrochloride in Tris-HCl buffer is 1 mg / mL.

[0019] Furthermore, in step B2, the mass ratio of undecylenic acid, NHS and DCC is 1:0.6:1.2.

[0020] Furthermore, in step B2, the mass concentration of undecylenic acid in toluene is 0.1 g / mL.

[0021] Furthermore, the preparation method of the modified polymer comprises the following steps: adding modified oxygen-carrying microspheres, modified talc, methyl methacrylate, acrylic acid, butyl acrylate and styrene to ethyl acetate, stirring and mixing evenly, introducing nitrogen, adding azobisisobutyronitrile, heating and stirring at 70-80°C and 200-300 rpm for reaction for 4-5 h, and removing ethyl acetate under reduced pressure to obtain a modified polymer.

[0022] Furthermore, the added amount of azobisisobutyronitrile is 0.5wt% of butyl acrylate.

[0023] Furthermore, the usage ratio of the modified talc to ethyl acetate is 1 g:200 mL.

[0024] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for making cellulose pulp from reed bamboo raw materials by biological fermentation. Reed bamboo is used as raw material, pulping is carried out by microbial aerobic fermentation, and pulp fiber is obtained by biological fermentation instead of chemical pulping, thereby avoiding the use of strong acid and alkali, realizing clean production, and utilizing the biological fermentation method to fully and effectively decompose lignin in plant fiber, which is beneficial to improving papermaking quality. The present invention uses Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus and Bacillus cereus to form a composite bacterial liquid, wherein each bacterial species is mutually beneficial and symbiotic, and synergistic, and a rich composite enzyme system is provided at the same time, which jointly promotes the efficient degradation of lignin, improves the quality of paper, utilizes biological treatment for pulping, avoids the use of a large number of chemical agents in traditional pulping, and reduces the discharge of wastewater in traditional pulping processes. The present invention prepares a modified polymer, introduces alkenyl groups on the surface of modified oxygen-carrying microspheres and modified talc, and copolymerizes with monomers such as styrene and acrylic acid, thereby cross-linking and grafting the oxygen-carrying microspheres and talc into the polymer, enhancing the interface bonding performance, improving the dispersibility, and cross-linking the modified polymer and pulp fibers with each other through hydrogen bonding forces, which can enhance the strength of paper and improve the hydrophobicity of the surface of paper, so that the prepared paper has better water resistance and moisture-proof functions. The present invention prepares modified oxygen-carrying microspheres, uses polylactic acid-glycolic acid copolymer and sodium alginate / polyvinyl alcohol to prepare double-layer microspheres, and coats the oxygen-carrying compound PFTBA, which can release oxygen, is conducive to the growth and proliferation of microorganisms, and improves the pulp yield. Double bonds are connected on the surface of the oxygen-carrying microspheres through a silane coupling agent, so that the oxygen-carrying microspheres participate in the polymerization reaction, improve the dispersibility of the microspheres, and improve the cross-linking degree between the polymer and the pulp fibers. The invention prepares modified talcum powder, and performs composite modification treatment on the talcum powder through dopamine hydrochloride coating and silane coupling agent surface modification. Firstly, the talcum powder is coated and modified by dopamine hydrochloride, and the dopamine hydrochloride can be oxidatively self-polymerized in a weakly alkaline environment of Tris-HCl buffer, and deposited on the surface of the talcum powder to form a polydopamine layer, and amino functional groups and hydroxyl functional groups are introduced on the surface of the talcum powder through the polydopamine, and the amino functional groups and hydroxyl functional groups on the surface of the talcum powder can be chemically bonded with undecylenic acid after carboxyl activation, so that the silane coupling agent can be firmly grafted on the surface of the polydopamine layer, and double bonds and hydrophobic groups are successfully introduced, so that the talcum powder can participate in the polymerization reaction, and is not easy to agglomerate as a filler, thereby enhancing the mechanical properties of paper and improving the water resistance of paper. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1This is a scanning electron microscope image of the paper described in Example 1 of the present invention; Figure 2 Physical property tests of the paper described in Examples 1-3 and Comparative Examples 1-3 of the present invention; Figure 3 This is a water resistance test of the paper described in Examples 1-3 of the present invention and Comparative Examples 1-3. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments. It should be noted that, unless otherwise specified, the chemical reagents involved in the present invention are purchased through commercial channels.

[0028] Embodiment 1: A method for preparing cellulose pulp from biological fermentation of Phragmites australis raw materials, comprising the following steps: (1) Cut the Phragmites australis into small pieces of 6 cm, remove the outer skin and leaves, and keep the inner stems, and spiral squeeze 5 times at 800 r / min, and air dry to obtain Phragmites australis residue; (2) The activated Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus, and Bacillus cereus were inoculated into LB liquid culture medium at a volume ratio of 10%, and cultured at 30°C and 180 rpm for 24 h; the Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus, and Bacillus cereus were purchased from the China General Microbiological Culture Collection Center, and the strain numbers were CGMCC 1.10314, CGMCC 1.14985, CGMCC 1.10291, and CGMCC 1.10559, respectively; (3) After culturing in step (2), Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus and Bacillus cereus were obtained respectively, and the obtained bacterial solutions were mixed to obtain a composite bacterial solution; the number of viable bacteria in the composite bacterial solution was 1.0×10 11 cfu / mL, the ratio of the viable counts of Bacillus licheniformis, Bacillus subtilis, Bacillus brevis, and Bacillus cereus was 1:1:1:1:1; (4) Add 100 g of the Phragmites australis residue obtained in step (1) to LB liquid culture medium, preferably to completely soak the residue in LB liquid culture medium, then add 10% of the volume of the composite bacterial solution in the LB liquid culture medium, mix well, and ferment for 12 h; (5) After fermentation for 12 h in step (4), 5 g of the modified polymer was added, stirred at 600 rpm for 3 h, and fermented for 36 h, filtered, washed, and refined with water at a mass ratio of 1:5. The refining gaps were 0.5 mm, 0.15 mm, and 0.08 mm, respectively. The pulp was heated at 60°C for 30 min, and sieved through a pulp screen with a gap of 1.5 mm for 20 min. (6) After the pulp is screened in step (5), papermaking is performed to make hand sheets, which are air-dried at 23°C. The paper weight is 80 g / m 2 .

[0029] The raw materials for preparing the modified polymer include the following components in parts by weight: 0.8 parts of methyl methacrylate, 0.7 parts of acrylic acid, 7 parts of butyl acrylate, 5 parts of styrene, 3 parts of modified oxygen-carrying microspheres, and 1.5 parts of modified talc.

[0030] The raw materials for preparing the modified oxygen-carrying microspheres include the following components in parts by weight: 1.5 parts of lecithin, 14 parts of perfluorotributylamine (PFTBA), 3 parts of allyltriethoxysilane, 3.2 parts of polylactic acid-glycolic acid copolymer (PLGA), 1.5 parts of polyvinyl alcohol, and 3 parts of sodium alginate.

[0031] The preparation material of modified oxygen-carrying microspheres comprises the following steps: A1: Add 1.5 g of lecithin to 10 mL of PBS buffer at pH 7.4, perform ultrasonic emulsification at 450 W for 3 times, each time for 20 s, with an interval of 45 s, add 14 g of PFTBA, perform emulsification 10 times according to the above steps, place in a hyperbaric oxygen chamber for 20 min, and filter through a 0.8 μm filter membrane to obtain a PFTBA emulsion; A2: Take the PFTBA emulsion obtained in step A1 and 3.2 g PLGA and add them to 80 mL dichloromethane, and ultrasonically emulsify them at 300 W for 35 s at 4°C. Then add 400 mL of 1 vol% Tween 80 aqueous solution and emulsify them at 200 W for 30 s at 4°C. -3 MPa, 500 rpm stirring for 3 h, washed with distilled water 5 times, centrifuged at 5000 rpm for 30 min, and the precipitate was freeze-dried at -40 °C to obtain PLGA microspheres; A3: Add 1.5 g polyvinyl alcohol and 3 g sodium alginate to 37.5 mL deionized water and mix well. Heat at 90°C for 30 min to obtain a polyvinyl alcohol / sodium alginate solution. Add the PLGA microspheres obtained in step A2 to the polyvinyl alcohol / sodium alginate solution, stir at 300 rpm for 30 min, add dropwise to a 0.02 g / mL calcium chloride solution, stir at 300 rpm for 2 h, filter, wash the filter cake with deionized water, and dry in vacuo at 50°C to obtain oxygen-carrying microspheres. A4: Add 3 g of allyltriethoxysilane to 60 mL of tetrahydrofuran and mix well to obtain a silane solution. Add the oxygen-carrying microspheres obtained in step A3 to the silane solution, stir at 400 rpm for 5 h, centrifuge at 5000 rpm for 30 min, wash the precipitate with deionized water, and dry under vacuum at 60°C to obtain modified oxygen-carrying microspheres.

[0032] The raw materials for preparing the modified talc powder include the following components in parts by weight: 3 parts of talc powder, 0.6 parts of dopamine hydrochloride, and 1.5 parts of undecylenic acid.

[0033] The preparation method of modified talcum powder comprises the following steps: B1: Dissolve 0.6 g dopamine hydrochloride in 600 mL Tris-HCl buffer, add 3 g talc, stir at 300 rpm for 1.5 h, filter, wash the filter cake with deionized water, and dry at 80°C to obtain coated talc; B2: Add 1.5 g of undecylenic acid to 15 mL of toluene, add 1.8 g of DCC and 0.9 g of NHS, stir at 300 rpm for 6 h, add the coated talc obtained in step B1, stir at 50°C and 300 rpm for 4 h, centrifuge at 5000 rpm for 20 min, wash the precipitate with deionized water, and dry in vacuo at 70°C to obtain modified talc.

[0034] The preparation method of the modified polymer comprises the following steps: adding 3 g of modified oxygen-carrying microspheres, 1.5 g of modified talc, 0.8 g of methyl methacrylate, 0.7 g of acrylic acid, 7 g of butyl acrylate and 5 g of styrene to 300 mL of ethyl acetate, stirring and mixing evenly, introducing nitrogen, adding 35 mg of azobisisobutyronitrile, heating and stirring at 80° C. and 300 rpm for reaction for 5 h, removing the ethyl acetate under reduced pressure, and obtaining a modified polymer.

[0035] Embodiment 2: A method for preparing cellulose pulp from biological fermentation of Phragmites australis raw materials, comprising the following steps: (1) Cut the Phragmites australis into small pieces of 4 cm, remove the outer skin and leaves, and keep the inner stems, and spiral squeeze for 3 times at 700 r / min, and air-dry to obtain Phragmites australis residue; (2) The activated Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus, and Bacillus cereus were inoculated into LB liquid culture medium at a volume ratio of 10%, and cultured at 30°C and 180 rpm for 24 h; the Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus, and Bacillus cereus were purchased from the China General Microbiological Culture Collection Center, and the strain numbers were CGMCC 1.10314, CGMCC 1.14985, CGMCC 1.10291, and CGMCC 1.10559, respectively; (3) After culturing in step (2), Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus and Bacillus cereus were obtained respectively, and the obtained bacterial solutions were mixed to obtain a composite bacterial solution; the number of viable bacteria in the composite bacterial solution was 1.0×10 11 cfu / mL, the ratio of the viable counts of Bacillus licheniformis, Bacillus subtilis, Bacillus brevis, and Bacillus cereus was 1:1:1:1:1; (4) Add 90 g of Phragmites australis residue obtained in step (1) to LB liquid culture medium, preferably to completely soak it in LB liquid culture medium, then add 10% of the volume of LB liquid culture medium composite bacterial solution, mix well, and ferment for 12 h; (5) After fermentation for 12 h in step (4), 6 g of modified polymer was added, stirred at 500 rpm for 2 h, and fermented for 36 h. The mixture was filtered, washed, and refined with water in a mass ratio of 1:5. The refining gaps were 0.5 mm, 0.15 mm, and 0.08 mm, respectively. The mixture was heated at 60° C. for 20 min, and sieved through a pulp screen with a gap of 1.5 mm for 15 min. (6) After the pulp is screened in step (5), papermaking is performed to make hand sheets, which are air-dried at 23°C. The paper weight is 80 g / m 2 .

[0036] The raw materials for preparing the modified polymer include the following components in parts by weight: 0.6 parts of methyl methacrylate, 0.5 parts of acrylic acid, 5 parts of butyl acrylate, 3 parts of styrene, 2 parts of modified oxygen-carrying microspheres, and 1 part of modified talc.

[0037] The raw materials for preparing the modified oxygen-carrying microspheres include the following components in parts by weight: 1 part of lecithin, 9 parts of perfluorotributylamine (PFTBA), 2 parts of allyltriethoxysilane, 2 parts of polylactic acid-glycolic acid copolymer (PLGA), 1 part of polyvinyl alcohol, and 1.5 parts of sodium alginate.

[0038] The preparation material of modified oxygen-carrying microspheres comprises the following steps: A1: Add 1 g of lecithin to 10 mL of PBS buffer at pH 7.4, perform ultrasonic emulsification at 450W for 3 times, each time for 20 s, with an interval of 45 s, add 9 g of PFTBA, perform emulsification 10 times according to the above steps, place in a hyperbaric oxygen chamber for 15 min, and filter through a 0.8 μm filter membrane to obtain a PFTBA emulsion; A2: Take the PFTBA emulsion obtained in step A1 and 2 g PLGA and add them to 50 mL dichloromethane, and ultrasonically emulsify them at 300 W at 4°C for 25 s. Then add 200 mL of 1 vol% Tween 80 aqueous solution and emulsify them at 200 W at 4°C for 30 s. -3MPa, stirred at 400 rpm for 3 h, washed with distilled water three times, centrifuged at 5000 rpm for 20 min, and the precipitate was freeze-dried at -40 °C to obtain PLGA microspheres; A3: Add 1 g polyvinyl alcohol and 1.5 g sodium alginate to 25 mL deionized water and mix well. Heat at 80°C for 20 min to obtain a polyvinyl alcohol / sodium alginate solution. Add the PLGA microspheres obtained in step A2 to the polyvinyl alcohol / sodium alginate solution, stir at 200 rpm for 20 min, add dropwise to a 0.02 g / mL calcium chloride solution, stir at 200 rpm for 1 h, filter, wash the filter cake with deionized water, and dry in vacuo at 40°C to obtain oxygen-carrying microspheres. A4: Add 2 g of allyltriethoxysilane to 40 mL of tetrahydrofuran and mix well to obtain a silane solution. Add the oxygen-carrying microspheres obtained in step A3 to the silane solution, stir at 300 rpm for 4 h, centrifuge at 5000 rpm for 20 min, wash the precipitate with deionized water, and dry under vacuum at 60°C to obtain modified oxygen-carrying microspheres.

[0039] The raw materials for preparing the modified talc powder include the following components in parts by weight: 2 parts of talc powder, 0.4 parts of dopamine hydrochloride, and 1 part of undecylenic acid.

[0040] The preparation method of modified talcum powder comprises the following steps: B1: Dissolve 0.4 g dopamine hydrochloride in 400 mL Tris-HCl buffer, add 2 g talc, stir at 200 rpm for 1 h, filter, wash the filter cake with deionized water, and dry at 80°C to obtain coated talc; B2: Add 1 g of undecylenic acid to 10 mL of toluene, add 1.2 g of DCC and 0.6 g of NHS, stir at 200 rpm for 5 h, add the coated talc obtained in step B1, stir at 40°C and 200 rpm for 3 h, centrifuge at 5000 rpm for 20 min, wash the precipitate with deionized water, and dry in vacuum at 60°C to obtain modified talc.

[0041] The preparation method of the modified polymer comprises the following steps: adding 2 g of modified oxygen-carrying microspheres, 1 g of modified talc, 0.6 g of methyl methacrylate, 0.5 g of acrylic acid, 5 g of butyl acrylate and 3 g of styrene to 200 mL of ethyl acetate, stirring and mixing evenly, introducing nitrogen, adding 25 mg of azobisisobutyronitrile, heating and stirring at 70°C and 200 rpm for 4 h, removing the ethyl acetate under reduced pressure, and obtaining a modified polymer.

[0042] Embodiment 3: A method for preparing cellulose pulp from biological fermentation of Phragmites australis raw materials, comprising the following steps: (1) Cut the Phragmites australis into small pieces of 5 cm, remove the outer skin and leaves, and keep the inner stems, and spiral squeeze 4 times at 750 r / min, and air dry to obtain Phragmites australis residue; (2) The activated Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus, and Bacillus cereus were inoculated into LB liquid culture medium at a volume ratio of 10%, and cultured at 30°C and 180 rpm for 24 h; the Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus, and Bacillus cereus were purchased from the China General Microbiological Culture Collection Center, and the strain numbers were CGMCC 1.10314, CGMCC 1.14985, CGMCC 1.10291, and CGMCC 1.10559, respectively; (3) After culturing in step (2), Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus and Bacillus cereus were obtained respectively, and the obtained bacterial solutions were mixed to obtain a composite bacterial solution; the number of viable bacteria in the composite bacterial solution was 1.0×10 11 cfu / mL, the ratio of the viable counts of Bacillus licheniformis, Bacillus subtilis, Bacillus brevis, and Bacillus cereus was 1:1:1:1:1; (4) Add 90 g of the Phragmites australis residue obtained in step (1) to LB liquid culture medium, preferably to completely soak it in LB liquid culture medium, then add 10% of the volume of the composite bacterial solution of LB liquid culture medium, mix well, and ferment for 12 h; (5) After fermentation for 12 h in step (4), 5 g of modified polymer was added, stirred at 550 rpm for 2.5 h, and fermented for 36 h. The mixture was filtered, washed, and refined with water in a mass ratio of 1:5. The refining gaps were 0.5 mm, 0.15 mm, and 0.08 mm, respectively. The mixture was heated at 60° C. for 25 min, and sieved through a pulp screen with a gap of 1.5 mm for 18 min. (6) After the pulp is screened in step (5), papermaking is performed to make hand sheets, which are air-dried at 23°C. The paper weight is 80 g / m 2 .

[0043] The raw materials for preparing the modified polymer include the following components in parts by weight: 0.7 parts of methyl methacrylate, 0.6 parts of acrylic acid, 6 parts of butyl acrylate, 4 parts of styrene, 2.5 parts of modified oxygen-carrying microspheres, and 1.2 parts of modified talc.

[0044] The raw materials for preparing the modified oxygen-carrying microspheres include the following components in parts by weight: 1.2 parts of lecithin, 12 parts of perfluorotributylamine (PFTBA), 2.5 parts of allyltriethoxysilane, 2.5 parts of polylactic acid-glycolic acid copolymer (PLGA), 1.2 parts of polyvinyl alcohol, and 2 parts of sodium alginate.

[0045] The preparation material of modified oxygen-carrying microspheres comprises the following steps: A1: Add 1.2 g of lecithin to 10 mL of PBS buffer at pH 7.4, perform ultrasonic emulsification at 450 W for 3 times, each time for 20 s, with an interval of 45 s, add 12 g of PFTBA, perform emulsification 10 times according to the above steps, place in a hyperbaric oxygen chamber for 18 min, and filter through a 0.8 μm filter membrane to obtain a PFTBA emulsion; A2: The PFTBA emulsion obtained in step A1 and 2.5 g PLGA were added to 62.5 mL dichloromethane and ultrasonically emulsified at 300 W for 30 s at 4 °C. 300 mL of 1 vol% Tween 80 aqueous solution was added and emulsified at 200 W for 30 s at 4 °C. -3 MPa, stirred at 450 rpm for 3 h, washed with distilled water 4 times, centrifuged at 5000 rpm for 25 min, and the precipitate was freeze-dried at -40 °C to obtain PLGA microspheres; A3: Add 1.2 g polyvinyl alcohol and 2 g sodium alginate to 30 mL deionized water and mix well. Heat at 85°C for 25 min to obtain a polyvinyl alcohol / sodium alginate solution. Add the PLGA microspheres obtained in step A2 to the polyvinyl alcohol / sodium alginate solution, stir at 250 rpm for 25 min, add dropwise to a 0.02 g / mL calcium chloride solution, stir at 250 rpm for 1.5 h, filter, wash the filter cake with deionized water, and dry in vacuo at 45°C to obtain oxygen-carrying microspheres. A4: Add 2.5 g of allyltriethoxysilane to 50 mL of tetrahydrofuran and mix well to obtain a silane solution. Add the oxygen-carrying microspheres obtained in step A3 to the silane solution, stir at 350 rpm for 4.5 h, centrifuge at 5000 rpm for 25 min, wash the precipitate with deionized water, and dry in vacuo at 60°C to obtain modified oxygen-carrying microspheres.

[0046] The raw materials for preparing the modified talc powder include the following components in parts by weight: 2.5 parts of talc powder, 0.5 parts of dopamine hydrochloride, and 1.2 parts of undecylenic acid.

[0047] The preparation method of modified talcum powder comprises the following steps: B1: Dissolve 0.5 g dopamine hydrochloride in 500 mL Tris-HCl buffer, add 2.5 g talc, stir at 250 rpm for 1.2 h, filter, wash the filter cake with deionized water, and dry at 80 °C to obtain coated talc; B2: Add 1.2 g of undecylenic acid to 12 mL of toluene, add 1.44 g of DCC and 0.72 g of NHS, stir at 250 rpm for 5.5 h, add the coated talc obtained in step B1, stir at 45°C and 250 rpm for 3.5 h, centrifuge at 5000 rpm for 20 min, wash the precipitate with deionized water, and dry in vacuo at 65°C to obtain modified talc.

[0048] The preparation method of the modified polymer comprises the following steps: 2.5 g of modified oxygen-carrying microspheres, 1.2 g of modified talc, 0.7 g of methyl methacrylate, 0.6 g of acrylic acid, 6 g of butyl acrylate and 4 g of styrene are mixed and added into 240 mL of ethyl acetate, and the mixture is stirred and mixed evenly, nitrogen is introduced, 30 mg of azobisisobutyronitrile is added, the mixture is heated and stirred at 75° C. and 250 rpm for reaction for 4.5 h, and the ethyl acetate is removed under reduced pressure to obtain a modified polymer.

[0049] The only difference between Comparative Example 1 and Example 1 is that no modified polymer is added.

[0050] The only difference between Comparative Example 2 and Example 1 is that no modified oxygen-carrying microspheres are added.

[0051] The only difference between Comparative Example 3 and Example 1 is that no modified talc is added.

[0052] Experimental Example 1: The paper prepared in Example 1 was observed by scanning electron microscope. The results are as follows: Figure 1 As shown, Figure 1 The results showed that the paper fibers were interwoven with each other, had good cross-linking, had some filler and other particles attached to the surface, and had small gaps between the fibers.

[0053] Experimental Example 2: Take the hand sheets prepared in Examples 1-3 and Comparative Examples 1-3, and use a horizontal tensile strength tester to test the tensile strength. Cut the paper with measured thickness and gram weight into 3 cm wide strips. The tear strength is measured by a tear strength tester. Fold the paper cut into 10 cm long and 5 cm wide in half and put it into the test. Each paper is measured three times and the average value is taken. The ring compression strength is measured by a ring compression strength tester. Cut the paper into 10 cm long and 2 cm wide strips through a ring compression sampler. The results are shown in Table 1.

[0054] Table 1:

[0055] The results in Table 1 show that the paper tensile strength, tear strength and ring crush strength of Examples 1-3 are all higher than those of Comparative Examples 1-3, indicating that the addition of modified polymers can significantly improve the physical properties of paper, enhance the bonding force between fibers, improve the overall performance of paper, and effectively enhance the strength and durability of paper.

[0056] Experimental Example 3: Using an automatic Cobb value tester, the surface water absorption capacity of the paper sample was measured according to GB / T 1540-2002 "Determination of water absorption of paper and paperboard (Cobb method)", and the experimental data was collected for 60 seconds. The results are as follows Figure 2 shown.

[0057] Figure 2 The results show that the Cobb values ​​of Examples 1-3 are lower than those of Comparative Examples 1-3, indicating that adding modified polymers can reduce the Cobb value of paper, that is, improve the water resistance of paper, so that the prepared paper has better water and moisture resistance.

[0058] Experimental Example 4: Pulping was performed according to the methods of Examples 1-3 and Comparative Examples 1-3, and the pulp yield was calculated. The pulp yield was calculated by the following formula: pulp yield (%) = m1 / m×100%, where m1 is the dry weight of the pulp obtained and m is the dry weight of the raw material of Phyllostachys australis. The results are shown in FIG. Figure 3 shown.

[0059] Figure 3 The results showed that the pulp yields of Examples 1-3 and Comparative Examples 1-3 were all above 50%, indicating that biological fermentation pulping has a higher pulp yield, among which the pulp yield of Examples 1-3 was higher than that of Comparative Examples 1-3, indicating that the addition of modified polymers can improve the pulp yield, and oxygen-release microspheres can effectively release oxygen, promote the growth and proliferation of microorganisms, and improve the pulp yield.

[0060] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A method for making cellulose pulp from biological fermentation of Phragmites australis raw materials, characterized in that: The following steps are involved: (1) cutting the Phragmites australis into small pieces, retaining the inner stems, spirally squeezing, and air-drying to obtain Phragmites australis residue; (2) The activated Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus, and Bacillus cereus were inoculated into LB liquid medium and cultured for 24 h; (3) After culturing in step (2), a bacterial solution of Bacillus licheniformis, a bacterial solution of Bacillus subtilis, a bacterial solution of Bacillus pumilus, and a bacterial solution of Bacillus cereus are obtained respectively, and the obtained bacterial solutions are compounded and mixed to obtain a composite bacterial solution; (4) adding the Phragmites australis residue obtained in step (1) to LB liquid culture medium, preferably to completely soak the residue in LB liquid culture medium, then adding 10% of the volume of the composite bacterial solution of LB liquid culture medium, mixing well, and fermenting for 12 h; (5) After fermentation for 12 h in step (4), add the modified polymer, stir, continue fermentation, filter, wash, add water for grinding, and screen the pulp; (6) After the pulp is screened in step (5), papermaking is performed to make hand sheets, which are then air-dried; The raw materials for preparing the modified polymer include the following components in parts by weight: 0.6-0.8 parts of methyl methacrylate, 0.5-0.7 parts of acrylic acid, 5-7 parts of butyl acrylate, 3-5 parts of styrene, 2-3 parts of modified oxygen-carrying microspheres, and 1-1.5 parts of modified talc; The raw materials for preparing the modified oxygen-carrying microspheres include the following components in parts by weight: 1-1.5 parts of lecithin, 9-14 parts of PFTBA, 2-3 parts of allyltriethoxysilane, 2-3.2 parts of PLGA, 1-1.5 parts of polyvinyl alcohol, and 1.5-3 parts of sodium alginate; The preparation material of the modified oxygen-carrying microspheres comprises the following steps: A1: Add lecithin to PBS buffer at pH 7.4, perform ultrasonic emulsification, add PFTBA, perform emulsification, place in a hyperbaric oxygen chamber, and filter through a 0.8 μm filter membrane to obtain a PFTBA emulsion; A2: Take the PFTBA emulsion obtained in step A1 and PLGA, add them to dichloromethane, emulsify, add 1 vol% Tween 80 aqueous solution, emulsify, and -3 MPa stirring, washing with distilled water, centrifugation, and freeze-drying of the precipitate to obtain PLGA microspheres; A3: Add polyvinyl alcohol and sodium alginate to deionized water, mix well, heat to obtain a polyvinyl alcohol / sodium alginate solution, add the PLGA microspheres obtained in step A2 to the polyvinyl alcohol / sodium alginate solution, stir, add dropwise to a 0.02 g / mL calcium chloride solution, stir, filter, wash the filter cake with deionized water, and vacuum dry to obtain oxygen-carrying microspheres; A4: adding allyltriethoxysilane to tetrahydrofuran and mixing to obtain a silane solution, adding the oxygen-carrying microspheres obtained in step A3 to the silane solution, stirring, centrifuging, washing the precipitate with deionized water, and vacuum drying to obtain modified oxygen-carrying microspheres; The raw materials for preparing the modified talc powder include the following components in parts by weight: 2-3 parts of talc powder, 0.4-0.6 parts of dopamine hydrochloride, and 1-1.5 parts of undecylenic acid; The preparation method of the modified talcum powder comprises the following steps: B1: dissolving dopamine hydrochloride in Tris-HCl buffer, adding talcum powder, stirring, filtering, washing the filter cake with deionized water, and drying to obtain coated talcum powder; B2: Add undecylenic acid to toluene, add DCC and NHS, stir, add the coated talc obtained in step B1, stir, centrifuge, wash the precipitate with deionized water, and vacuum dry to obtain modified talc; The preparation method of the modified polymer comprises the following steps: adding modified oxygen-carrying microspheres, modified talcum powder, methyl methacrylate, acrylic acid, butyl acrylate and styrene to ethyl acetate, stirring and mixing evenly, introducing nitrogen, adding azobisisobutyronitrile, heating and stirring for reaction, and removing ethyl acetate under reduced pressure to obtain the modified polymer.

2. The method for making cellulose pulp from Phyllostachys australis raw material by biological fermentation according to claim 1, characterized in that: In step (3), the number of viable bacteria in the composite bacterial solution is 1.0×10 11 cfu / mL, the ratio of the viable counts of Bacillus licheniformis, Bacillus subtilis, Bacillus pumilus and Bacillus cereus is 1:1:1:1:1; in step (5), the mass ratio of the modified polymer to the reed residue is 1:15-20 g.

3. The method for making cellulose pulp from Phyllostachys australis raw material by biological fermentation according to claim 2, characterized in that: In step A1, the mass concentration of the lecithin in the PBS buffer is 0.1-0.15 g / mL.

4. The method for making cellulose pulp from Phyllostachys australis raw material by biological fermentation according to claim 3, characterized in that: In step A2, the mass concentration of PLGA in dichloromethane is 40 mg / mL; the volume ratio of dichloromethane to Tween aqueous solution is 1:4-5.

5. The method for making cellulose pulp from Phyllostachys australis raw material by biological fermentation according to claim 4, characterized in that: In step A3, the mass concentration of the polyvinyl alcohol in deionized water is 0.04 g / mL.

6. The method for making cellulose pulp from Phyllostachys australis raw material by biological fermentation according to claim 5, characterized in that: In step A4, the mass concentration of allyltriethoxysilane in tetrahydrofuran is 0.05 g / mL.

7. The method for making cellulose pulp from Phyllostachys australis raw material by biological fermentation according to claim 6, characterized in that: In step B1, the mass concentration of dopamine hydrochloride in Tris-HCl buffer is 1 mg / mL.

8. The method for making cellulose pulp from Phyllostachys australis raw material by biological fermentation according to claim 7, characterized in that: In step B2, the mass ratio of undecylenic acid, NHS and DCC is 1:0.6:1.2; the mass concentration of undecylenic acid in toluene is 0.1 g / mL.

9. The method for making cellulose pulp from Phyllostachys australis raw material by biological fermentation according to claim 8, characterized in that: The amount of azobisisobutyronitrile added is 0.5wt% of butyl acrylate; the amount ratio of modified talc to ethyl acetate is 1 g:200mL.

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