WO2022199716A1 - 纤维素耐水纸及其制备方法 - Google Patents

纤维素耐水纸及其制备方法 Download PDF

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WO2022199716A1
WO2022199716A1 PCT/CN2022/094826 CN2022094826W WO2022199716A1 WO 2022199716 A1 WO2022199716 A1 WO 2022199716A1 CN 2022094826 W CN2022094826 W CN 2022094826W WO 2022199716 A1 WO2022199716 A1 WO 2022199716A1
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water
cellulose
paper
preparation
fibers
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English (en)
French (fr)
Inventor
祝名伟
黄大方
陈延峰
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Nanjing University
Nanjing Tech University
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Nanjing University
Nanjing Tech University
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
    • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
    • D21H23/22—Addition to the formed paper
    • D21H23/32—Addition to the formed paper by contacting paper with an excess of material, e.g. from a reservoir or in a manner necessitating removal of applied excess material from the paper
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H25/00—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
    • D21H25/04—Physical treatment, e.g. heating, irradiating
    • D21H25/06—Physical treatment, e.g. heating, irradiating of impregnated or coated paper

Definitions

  • the invention relates to the field of papermaking, in particular to a cellulose water-resistant paper and a preparation method thereof.
  • Paper is made of natural plant fibers, which are naturally degradable and environmentally friendly, but the important disadvantage of paper is that it has poor tolerance to water, and almost loses its strength when soaked in water or in a high humidity environment for a long time. This makes the application scenarios of paper very limited. If the paper can be made to have strong water resistance, so that it can work completely in the water environment, it will undoubtedly make up for the important shortcomings shared by paper materials, and it will greatly expand the application field of paper, realize new applications, and even in some fields. Replacing plastics and making an important contribution to environmental friendliness and sustainable development.
  • the water resistance of water-resistant paper is basically achieved by introducing additional hydrophobic additives during the preparation process.
  • hydrophobic inorganic or organic materials such as rosin, paraffin, and synthetic resin can be introduced by filling, dipping, and coating methods.
  • starch protect the natural cellulose fibers from contact with water and other media to achieve the preparation of water-resistant paper; or after the paper is prepared, spray a water repellant on its surface to make the paper water-resistant.
  • Another type is to modify, regenerate, cross-link, and graft fibers by introducing new substitution groups, which can fix the relative position of fibers, thereby enhancing their stability in water and other systems.
  • the traditional preparation method not only has complicated process and low production efficiency, but also has different raw materials, resulting in high production costs; in addition, since some raw materials are not degradable, the use of these water-resistant papers will also cause pollution, which is not environmentally friendly. , and this also greatly limits the application scenarios of water-resistant paper. For example, when water-resistant paper is used in cell reproduction research, the water-resistant paper containing additives has poor biocompatibility, which will have a greater impact on the experiment.
  • One aspect of the present invention provides a preparation method of cellulose water-resistant paper, which comprises the following steps:
  • the cellulose paper is placed in the lye solution for 5 seconds to 72 hours, taken out, washed with water, and then dried; the mass percentage concentration of the lye solution is 10% to 35%, and the temperature of the lye solution is greater than or equal to 8°C , and the preparation process does not introduce hydrophobic additives.
  • the cellulose paper can be treated for 5 seconds to 72 hours by using alkali solution with a temperature of 8° C. or higher and a mass percentage concentration of 10% to 35%, so that the spatial shape of the fibers can be regulated, so that the fibers can be woven with each other, Locking, hooking, and forming strong physical connections, such strong physical interactions do not depend on the hydroxyl bonding between fibers, so they will not be affected by the invasion of water molecules.
  • the water-resistant paper prepared by the invention will not lose strength due to the destruction of hydrogen bonds in water, can work in water environment, and has good wet strength; most importantly, no other hydrophobic additives are introduced in the preparation process , it does not need to chemically modify the molecular structure of the fiber to introduce new water-resistant groups, which is environmentally friendly, has good biocompatibility, and reduces the limitation of raw materials, greatly reduces production costs, improves production efficiency, and has With superior performance and broad usage scenarios, it has good business prospects.
  • the cellulose paper is prepared from ⁇ -cellulose fibers with a crystallinity of 30% or more.
  • the alkaline solution is at least one of sodium hydroxide solution, potassium hydroxide solution, lithium hydroxide solution, calcium hydroxide solution, and ammonia water.
  • the sodium hydroxide solution is an aqueous sodium hydroxide solution, and the mass percentage concentration of the aqueous sodium hydroxide solution is 18% to 25%.
  • the fiber diameter of the cellulose paper ranges from 1 ⁇ m to 250 ⁇ m.
  • the fiber source of the cellulose paper is at least one of woody plants, lianas, and herbs.
  • the step of washing with water is neutralized with an acid.
  • the sample is kept under pressure.
  • the pressure maintaining pressure is 0.01MPa-20MPa, and the pressure maintaining time is 0.1h-24h.
  • a cellulose water-resistant paper wherein the fibers of the cellulose water-resistant paper are interlocked with each other, and the cellulose water-resistant paper does not contain a hydrophobic additive.
  • the cellulose water-resistant paper is prepared by the aforementioned preparation method.
  • Fig. 1 is the water-resistant paper prepared in Example 1;
  • Fig. 2 is the tensile strength test of the water-resistant paper test strip prepared in Example 1;
  • Fig. 3 is the contrast diagram of the stress-strain curve of the water-resistant paper prepared in Example 1 and ordinary paper;
  • Fig. 4 is the scanning electron microscope (SEM) picture of raw cotton cellulose fiber in embodiment 7;
  • Example 5 is a scanning electron microscope (SEM) image of the water-resistant paper fiber prepared in Example 7;
  • Figure 6 is a schematic diagram of the work of the instruments used in the characterization tests (1) to (4);
  • Fig. 7 is the comparison test result of abrasion resistance of the water-resistant paper prepared in Example 1 and ordinary cellulose paper;
  • Fig. 8 is the comparison test result of bursting strength of the water-resistant paper prepared in Example 1 and ordinary cellulose paper;
  • Fig. 9 is the comparison test result of the tearing degree of the water-resistant paper prepared in Example 1 and ordinary cellulose paper;
  • Fig. 10 is the comparison test result of the folding endurance of the water-resistant paper prepared in Example 1 and ordinary cellulose paper;
  • FIG. 11 is a comparison test result of softness between the water-resistant paper prepared in Example 1 and the ordinary cellulose paper.
  • first and second are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with “first”, “second” may expressly or implicitly include at least one of that feature.
  • plural means at least two, such as two, three, etc., unless expressly and specifically defined otherwise.
  • severeal means at least one, such as one, two, etc., unless expressly and specifically defined otherwise.
  • One aspect of the present invention provides a method for preparing cellulose water-resistant paper, comprising the following steps:
  • the cellulose paper is placed in the lye solution for 5 seconds to 72 hours, taken out, washed with water, and then dried; the mass percentage concentration of the lye solution is 10% to 35%, the temperature of the lye solution is greater than or equal to 8 ° C, and the preparation process No hydrophobic additives were introduced.
  • the natural cellulose crystal form in nature is cellulose type I, and the molecular chains of cellulose type I are arranged in parallel. After the cellulose paper is immersed in an alkaline solution, it is converted into cellulose type II after being treated with an alkaline solution. The molecular chains of the cellulose type II are anti-parallel. From the appearance, the cellulose type II is helical. Specifically, when the cellulose paper is immersed in the lye solution, it first swells, so that the alkali penetrates into the crystal plane of the crystallization zone and forms a hydrated crystalline compound with the cellulose molecules.
  • the treatment time in the alkali solution is 30 seconds to 48 hours, and further preferably, the treatment time in the alkali solution is 1 minute to 2 hours.
  • the treatment in the lye solution is carried out in 2 to 5 times, that is, after a certain period of treatment, it is taken out, and then immersed in the lye solution for treatment, and the process is repeated; preferably, the treatment is repeated 3 times.
  • the treatment in stages can make the fiber shape twist and bend more fully, enhance the inter-fiber hooking effect, and make the cellulose paper have better water resistance.
  • the mass percentage concentration of the lye solution is 15% to 28%.
  • the temperature of the lye solution is 18°C to 32°C.
  • the temperature and concentration of the lye are directly related to the adjustment and control of the fiber shape. Unsuitable temperature and concentration will cause the fiber to swell too much, resulting in the less typical hooking between the fibers, and it cannot have sufficient strength. It is difficult to achieve water resistance; Within the preset range, the swelling and torsion of the fibers reach an equilibrium state, which can greatly improve the water resistance and strength of the water-resistant paper.
  • the treatment time of lye is also related to the endowment of water resistance. Within the preset range, the reaction of cellulose can be carried out completely without affecting other properties of the paper.
  • the cellulose paper can be treated for 5 seconds to 72 hours by using alkali solution with a temperature of 8° C. or higher and a mass percentage concentration of 10% to 35%, so that the spatial shape of the fibers can be regulated, so that the fibers can be woven with each other, Locking, hooking, and forming strong physical connections, such strong physical interactions do not depend on the hydroxyl bonding between fibers, so they will not be affected by the invasion of water molecules.
  • the water-resistant paper prepared by the invention will not lose its strength due to the destruction of hydrogen bonds in water, can work in a water environment, and has better wet strength.
  • the cellulose paper is prepared from alpha-cellulose fibers having a crystallinity of 30% or greater.
  • the crystallinity of ⁇ -cellulose in the fiber used is greater than 30%, the fiber structure is sufficiently compact, and the bending shape change of the fiber after treatment will be more obvious. Fibers with too low crystallinity are easily dissolved in the lye solution within the concentration range of the present invention, because the distance between fibers with low crystallinity is far, and when the hydrogen bonds between fibers are destroyed by the lye solution, strong hydrogen cannot be formed again.
  • the alkaline solution is at least one of sodium hydroxide solution, potassium hydroxide solution, lithium hydroxide solution, calcium hydroxide solution, and ammonia water.
  • the sodium hydroxide solution is an aqueous sodium hydroxide solution, and the mass percentage concentration of the aqueous sodium hydroxide solution is 18% to 25%.
  • the fiber diameter of the cellulose paper is 1 ⁇ m ⁇ 250 ⁇ m, preferably, the fiber diameter of the cellulose paper is 5 ⁇ m ⁇ 180 ⁇ m, and more preferably, the fiber diameter of the cellulose is 10 ⁇ m ⁇ 50 ⁇ m.
  • the fibers within the predetermined diameter range can better adapt to the concentration of the lye solution and the treatment time in the present invention, and the strength of the fibers themselves will not be damaged while the water resistance is obtained.
  • the fiber source of the cellulose paper is at least one of woody plants, lianas, and herbs.
  • neutralization with an acid before the step of washing with water, and neutralization with an acid before washing with water can better remove the lye residue.
  • the sample is pressurized after the step of washing with water.
  • the pressure maintaining pressure is 0.01MPa-20MPa
  • the pressure maintaining time is 0.1h-24h. Holding the water-resistant paper under pressure can make the paper smoother and easier to dry, which is convenient for subsequent processing.
  • a cellulose water-resistant paper wherein the fibers of the cellulose water-resistant paper are interlocked with each other, and the cellulose water-resistant paper does not contain a hydrophobic additive.
  • the cellulose water-resistant paper is prepared by the aforementioned preparation method.
  • the prepared cellulose water-resistant paper does not contain hydrophobic additives, and is environmentally friendly and easy to decompose. After being completely immersed in water for 1 hour, the wet strength can reach up to 15.1 MPa, which has broad application prospects.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent In an aqueous sodium hydroxide solution with a concentration of 18% and a temperature of 25°C, take it out after 1 minute of reaction, fully neutralize it with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample,
  • the cellulose water-resistant paper material was obtained; the cellulose water-resistant paper material was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour, and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, about 15.0MPa.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent The concentration of 30%, the temperature of 25 °C sodium hydroxide aqueous solution, take out after 1 minute of reaction, fully neutralize with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample,
  • the cellulose water-resistant paper material was obtained; the cellulose water-resistant paper material was cut into a 10cm*1.5cm test strip, immersed in water for 1 hour and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, about 9.7MPa.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent The concentration of 10%, the temperature of 25 °C sodium hydroxide aqueous solution, take out after 1 minute of reaction, fully neutralize with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample, The cellulose water-resistant paper material was obtained; the cellulose water-resistant paper material was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, which was about 8.9MPa.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent The concentration of 18% and the temperature of 25 ° C sodium hydroxide aqueous solution, take out after 48 hours of reaction, fully neutralize with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample, The cellulose water-resistant paper material was obtained; the cellulose water-resistant paper material was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, which was about 14.1MPa.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent The concentration of 18%, the temperature of 25 °C potassium hydroxide aqueous solution, take out after 1 minute of reaction, fully neutralize with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample,
  • the cellulose water-resistant paper material was obtained; the cellulose water-resistant paper material was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, about 8.3MPa.
  • the lignin in the bamboo is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 230 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent The concentration of 18%, the temperature of 25 °C sodium hydroxide aqueous solution, take out after 1 minute of reaction, fully neutralize with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample,
  • the cellulose water-resistant paper material was obtained; the cellulose water-resistant paper material was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, which was about 7.6MPa.
  • the lignin in the vines is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 46% are obtained by extraction, and the fiber diameter is about 10 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, which is then placed in a mass Divide it into ammonia water with a concentration of 18% and a temperature of 25 ° C, take it out after 0.5 hours of reaction, neutralize it with an appropriate amount of acid, wash the sample with water three times to remove the residual chemicals, and then place the sample in a press, under pressure At 4MPa, hold the pressure for 0.5 hours, and then dry the sample to obtain a cellulose water-resistant paper material; cut the cellulose water-resistant paper material into a 10cm*1.5cm test strip, immerse it in water for 1 hour, take it out, and test it with a universal chemical testing machine
  • the wet tensile strength of the test strip is about 7.7MPa.
  • the lignin in the cotton fiber is removed, and the micron cellulose fiber with ⁇ -cellulose crystallinity of 85% is obtained by extraction, and the fiber diameter is about 20 ⁇ m.
  • the extracted fiber is prepared into cellulose paper, which is then placed in a mass Divide it into potassium hydroxide aqueous solution with a concentration of 35% and a temperature of 25 °C, take it out after 10 minutes of reaction, neutralize it with an appropriate amount of acid, and wash the sample with water three times to remove the residual chemicals; repeat the above steps three times, and then
  • the sample is placed in the press, and the pressure is kept at 2MPa for 24 hours, and then the sample is dried to obtain a cellulose water-resistant paper material; the cellulose water-resistant paper material is cut into 10cm*1.5cm test strips, immersed in water for 1 hour Then take it out, and test the wet tensile strength of the test strip with a universal mechanical testing machine, which is about 15.1MPa.
  • the lignin in the straw is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 47.6% are obtained by extraction, and the fiber diameter is about 25 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent In sodium hydroxide aqueous solution with a concentration of 15% and a temperature of 25 °C, take it out after 48 hours of reaction, neutralize it with an appropriate amount of acid, and wash the sample with water three times to remove the residual chemicals; repeat the above steps three times, and then the sample Put it in a press, hold the pressure for 0.5 hours at a pressure of 0.5MPa, and then dry the sample to obtain a cellulose water-resistant paper material; cut the cellulose water-resistant paper material into a 10cm*1.5cm test strip, and immerse it in water for 1 hour. Take it out and test the wet tensile strength of the test strip with a universal mechanical testing machine, about 10.9MPa.
  • the lignin in the straw is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 47.6% are obtained by extraction, and the fiber diameter is about 25 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent In sodium hydroxide aqueous solution with a concentration of 15% and a temperature of 15 ° C, take it out after 48 hours of reaction, neutralize it with an appropriate amount of acid, and wash the sample with water three times to remove the residual chemicals; repeat the above steps three times, and then the sample Put it in a press, hold the pressure for 0.5 hours at a pressure of 0.5MPa, and then dry the sample to obtain a cellulose water-resistant paper material; cut the cellulose water-resistant paper material into a 10cm*1.5cm test strip, and immerse it in water for 1 hour. Take it out and test the wet tensile strength of the test strip with a universal mechanical testing machine, about 8.9MPa.
  • the lignin in the straw is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 47.6% are obtained by extraction, and the fiber diameter is about 25 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent The concentration of 15%, the temperature of 35 °C sodium hydroxide aqueous solution, take out after 48 hours of reaction, after neutralization with an appropriate amount of acid, wash the sample with water three times to remove the residual chemicals; repeat the above steps three times, and then the sample Put it in a press, hold the pressure for 0.5 hours at a pressure of 0.5MPa, and then dry the sample to obtain a cellulose water-resistant paper material; cut the cellulose water-resistant paper material into a 10cm*1.5cm test strip, and immerse it in water for 1 hour. Take it out and test the wet tensile strength of the test strip with a universal mechanical testing machine, about 9.5MPa.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent The concentration of 7% and the temperature of 25 ° C sodium hydroxide aqueous solution, take out after 1 minute of reaction, fully neutralize with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample, A cellulose water-resistant paper material is obtained; the water-resistant paper is cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour, and taken out, and the wet tensile strength of the test strip is tested with a universal mechanical testing machine, which is about 0.1MPa.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent The concentration of 18% and the temperature of 5 °C sodium hydroxide aqueous solution, take out after 1 minute of reaction, fully neutralize with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample, A cellulose water-resistant paper material was obtained; the water-resistant paper was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour, and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, which was about 5.6MPa.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent In an aqueous sodium hydroxide solution with a concentration of 18% and a temperature of 25°C, take it out after 3 seconds of reaction, fully neutralize it with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample, A cellulose water-resistant paper material was obtained; the water-resistant paper was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, which was about 6.3MPa.
  • the lignin in the wood is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 20% are obtained by extraction, and the fiber diameter is about 15 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent In an aqueous sodium hydroxide solution with a concentration of 18% and a temperature of 25°C, take it out after 1 minute of reaction, fully neutralize it with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample, A cellulose water-resistant paper material was obtained; the water-resistant paper was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, which was about 1.5MPa.
  • the lignin in the bamboo is removed, and the micron cellulose fibers with ⁇ -cellulose crystallinity of 50% are obtained by extraction, and the fiber diameter is about 260 ⁇ m.
  • the extracted fibers are prepared into cellulose paper, and then placed in the mass percent In an aqueous sodium hydroxide solution with a concentration of 18% and a temperature of 25°C, take it out after 1 minute of reaction, fully neutralize it with an appropriate amount of acid, wash the sample with water three times to remove the residual sodium hydroxide and acid, and then dry the sample,
  • the cellulose water-resistant paper material was obtained; the water-resistant paper was cut into a test strip of 10cm*1.5cm, immersed in water for 1 hour and taken out, and the wet tensile strength of the test strip was tested with a universal mechanical testing machine, which was about 3.3MPa.
  • the cellulose water-resistant paper prepared in Example 1 and the ordinary cellulose paper that has not been soaked in alkali solution were additionally subjected to abrasion resistance test, burst test, tear test, folding endurance test and softness test. Proceed as follows:
  • Abrasion resistance of paper refers to a property that paper can resist surface abrasion under resistance.
  • the instrument used in this experiment is the Taber Abraser 5135 paper abrasion resistance tester produced by an American manufacturer, and its working mode is shown in Figure 6(a).
  • the test of wet abrasion resistance is to take out the sample paper after soaking in water for 1 hour, and then carry out the abrasion resistance test according to the above steps, and compare the abrasion resistance of the paper according to the number of turns when the paper is worn. Multiple samples were tested to reduce experimental error.
  • the bursting strength of paper refers to the maximum pressure that a unit area of paper can withstand before breaking, usually expressed in KPa.
  • the PTI F18533 cardboard bursting tester is used for testing, and the schematic diagram of its working mode is shown in Figure 6(b). Cut the paper sample into a square of 100mm ⁇ 100mm, after placing the sample, start the motor and record the pressure gauge value when the sample is broken. Wet samples were treated in the same way as the abrasion resistance test, and the test method was the same as that of dry samples. Take 3 test points for each sample, and test multiple samples to reduce errors.
  • X represents the burst index (kPa.m 2 /g)
  • p represents the burst strength (kPa)
  • g represents the weight of the paper sample (g/m 2 ).
  • the tearing degree of paper refers to the average value of the force required to tear the pre-cut paper to a certain length under specified conditions.
  • the L&W 009 tear tester produced by a Swedish company was used for the tear resistance test.
  • the schematic diagram of its working method is shown in Figure 6(c). Cut the paper sample into a rectangle of 75mm ⁇ 65mm, clamp the paper, and use the cutter on the instrument to make a neat incision. When the pointer is in contact with the stopper, quickly press the stopper of the pendulum with hand speed. When the pendulum returns to the starting position from the farthest point, gently stop the pendulum and read the displayed value. Wet samples were treated in the same way as the abrasion resistance test, and the test method was the same as that of dry samples. Test multiple samples to reduce errors.
  • the formula for calculating the tear index is as follows:
  • X represents the tear index (mN ⁇ m 2 /g)
  • a represents the tear degree (mN)
  • g represents the weight of the paper sample (g/m 2 ).
  • the folding endurance of paper refers to the number of times that the paper is folded back and forth at a fixed angle under a certain tension until it is broken, and is expressed in the number of times of back and forth folding.
  • the MIT/U21B folding endurance tester is used for the test, and the schematic diagram of its working mode is shown in Figure 6(d). Cut the pattern into a 15mm ⁇ 150mm strip, adjust the spring tension and folding head of the folding endurance tester to align the seam. Adjust the tension indicator, clamp the pattern, and then lock the tension lever to clamp the pattern. Release the tension bar lock, then start the test, the pattern begins to fold, until the pattern breaks, record the number of folds displayed by the instrument. Wet samples were treated in the same way as the abrasion resistance test, and the test method was the same as that of dry samples. Compare the number of folds to compare the excellent folding resistance of the paper. Test multiple samples to reduce errors.
  • the plate-shaped probe of the softness instrument presses the sample into the gap to a certain depth (about 8mm)
  • Softness expressed in mN.
  • the LB-R1000 computer softness tester produced by Lanbo Instrument Co., Ltd. is used.
  • the paper sample is cut into a size of 100mm ⁇ 100mm for testing, and the measured value on the display is read. 10 data should be tested in the horizontal and vertical directions. Wet samples were treated in the same way as the abrasion resistance test, and the test method was the same as that of dry samples.
  • the water-resistant paper prepared by the solution of the present invention has good wet strength. After soaking in water for one hour, the wet strength can reach up to 15.1MPa, and compared with the untreated ordinary cellulose paper, the wet strength can reach 15.1MPa. After wet, it has better abrasion resistance, burst resistance, tear resistance, folding resistance and softness.

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Abstract

本发明涉及造纸领域，特别是涉及一种纤维素耐水纸及其制备方法。本发明通过使用10％～35％质量百分浓度的碱液对纤维素纸处理10秒至72小时，能够对纤维空间形态进行调控，使纤维之间能相互编织、锁扣、勾连，形成强有力的物理连接，这样的物理强相互作用并不依赖于纤维间的羟基结合，因此不会受到水分子侵袭的影响。本发明制备的耐水纸不会因为在水中氢键被破坏从而失去强度，可以实现在水环境中工作，并具备较好的湿强度；最重要的是，制备过程中未引入其他疏水性的添加剂，环境友好，生物兼容性良好，且减少了原材料的限制，大大降低了生产成本，提高了生产效率，并兼具优越的性能和广阔的使用场景，具备良好的商业前景。

Description

纤维素耐水纸及其制备方法 技术领域
本发明涉及造纸领域，特别是涉及一种纤维素耐水纸及其制备方法。
背景技术
目前，“塑料危机”已经严重危害自然环境，微塑料甚至已随着水循环进入食物链，并最终进入人体，危害人类的健康。纸是由天然植物纤维制造而成的，可自然降解、环境友好，但纸的重要缺点是对水的耐受性比较差，被水浸泡，或长时间处于高湿环境中几乎失去了强度，这使得纸的应用场景十分受限。如果能使得纸具有强的耐水性，使其可完全在水环境中工作，无疑弥补了纸类材料所共有的重要短板，将大大拓展纸的应用领域，实现新的应用，甚至在部分领域替代塑料，为环境友好和可持续发展做出重要贡献。
目前，耐水纸耐水性能的获得基本通过在制备过程中引入额外的疏水性添加剂实现，例如，可以通过填充、浸入、包覆等方法引入疏水性的无机或有机材料如松香胶、石蜡、合成树脂或淀粉，把天然纤维素纤维保护起来，避免其同水等介质的接触以实现耐水纸的制备；或是在纸张制备完成后，在其表面喷涂防水剂，以使纸张获得耐水性。还有一类是通过引入新的取代集团，对纤维进行改性、再生、交联，接枝等，可以固定纤维的相对位置，从而增强其在水等体系中的稳定性。
然而，传统的制备方法不仅工艺复杂、生产效率低，而且原料不单一，因此造成了生产成本居高不下；此外，由于部分原料不可降解，这些耐水纸的使用同样会造成污染，并不环境友好，而且，这也大大限制了耐水纸的应用场景，例如当将耐水纸应用在细胞繁殖研究中时，含有添加剂的耐水纸生物相容性较 差，会对实验造成较大的影响。
发明内容
基于此，有必要提供一种无需外加疏水性添加剂仍能保证耐水性能的耐水纸。
本发明的一个方面，提供了一种纤维素耐水纸的制备方法，其包括以下步骤：
将纤维素纸置于碱液中处理5秒至72小时，取出后用水清洗，然后干燥；所述碱液的质量百分浓度为10％～35％，所述碱液的温度大于等于8℃，且制备过程不引入疏水性添加剂。
本发明通过使用温度大于等于8℃、质量百分浓度为10％～35％的碱液对纤维素纸处理5秒至72小时，能够对纤维空间形态进行调控，使纤维之间能相互编织、锁扣、勾连，形成强有力的物理连接，这样的物理强相互作用并不依赖于纤维间的羟基结合，因此不会受到水分子侵袭的影响。本发明制备的耐水纸不会因为在水中氢键被破坏从而失去强度，可以实现在水环境中工作，并具备较好的湿强度；最重要的是，制备过程中未引入其他疏水性的添加剂，也不需要通过对纤维分子结构进行化学改性，引入新的耐水基团，对环境友好，生物兼容性良好，且减少了原材料的限制，大大降低了生产成本，提高了生产效率，并兼具优越的性能和广阔的使用场景，具备良好的商业前景。
在其中一个实施例中，所述纤维素纸由结晶度大于等于30％的α-纤维素纤维制备。
在其中一个实施例中，所述碱液为氢氧化钠溶液、氢氧化钾溶液、氢氧化锂溶液、氢氧化钙溶液、氨水中的至少一种。
在其中一个实施例中，所述氢氧化钠溶液为氢氧化钠水溶液，所述氢氧化钠水溶液的质量百分浓度为18％～25％。
在其中一个实施例中，所述纤维素纸的纤维直径为1μm～250μm。
在其中一个实施例中，所述纤维素纸的纤维来源为木本植物、藤本植物、草本植物中的至少一种。
在其中一个实施例中，所述用水清洗的步骤前，用酸进行中和。
在其中一个实施例中，所述用水清洗的步骤后，将样品进行保压。
在其中一个实施例中，所述保压的压力为0.01MPa～20MPa，所述保压的时间为0.1h～24h。
本发明的另一方面，还提供了一种纤维素耐水纸，所述纤维素耐水纸的纤维之间互相勾连，且所述纤维素耐水纸不含疏水性添加剂。
在其中一个实施例中，所述纤维素耐水纸由前述制备方法制备得到。
附图说明
图1为实施例1制备得到的耐水纸；
图2为实施例1制备得到的耐水纸试条的抗拉强度测试；
图3为实施例1制备得到的耐水纸与普通纸应力应变曲线的对比图；
图4为实施例7中原始棉纤维素纤维的扫描电镜(SEM)图；
图5为实施例7制备的耐水纸纤维的扫描电镜(SEM)图；
图6为表征测试(1)～(4)中所用仪器的工作示意简图；
图7为实施例1制备得到的耐水纸与普通纤维素纸的耐磨强度对比测试结果；
图8为实施例1制备得到的耐水纸与普通纤维素纸的耐破度对比测试结果；
图9为实施例1制备得到的耐水纸与普通纤维素纸的撕裂度对比测试结果；
图10为实施例1制备得到的耐水纸与普通纤维素纸的耐折度对比测试结果；
图11为实施例1制备得到的耐水纸与普通纤维素纸的柔软度对比测试结果。
具体实施方式
为了便于理解本发明，下面将参照相关附图对本发明进行更全面的描述。附图中给出了本发明的较佳实施例。但是，本发明可以以许多不同的形式来实现，并不限于本文所描述的实施例。相反地，提供这些实施例的目的是使对本发明的公开内容的理解更加透彻全面。
此外，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。在发明的描述中，“多个”的含义是至少两个，例如两个，三个等，除非另有明确具体的限定。在本发明的描述中，“若干”的含义是至少一个，例如一个，两个等，除非另有明确具体的限定。
除非另有定义，本文所使用的所有的技术和科学术语与属于本发明的技术领域的技术人员通常理解的含义相同。本文中在本发明的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本发明。本文所使用的术语“和/或”包括一个或多个相关的所列项目的任意的和所有的组合。
本发明的一个方面，提供了一种纤维素耐水纸的制备方法，包括以下步骤：
将纤维素纸置于碱液中处理5秒至72小时，取出后用水清洗，然后干燥；碱液的质量百分浓度为10％～35％，碱液的温度大于等于8℃，且制备过程不引入疏水性添加剂。
自然界中的天然纤维素晶型为纤维素Ⅰ型，纤维素Ⅰ型的分子链为平行排列。纤维素纸浸入碱性溶液中之后，经碱性溶液处理转变为纤维素Ⅱ型，纤维素Ⅱ型的分子链为反平行，从外观上看，纤维素Ⅱ型为螺旋形。具体地，纤维素纸浸入碱液中，首先发生溶胀，使得碱渗入到结晶区晶面，与纤维素分子形成水合结晶化合物，纤维素Ⅰ型晶面间距增大，晶面发生变形或破坏，部分形成无定形结构；清洗去除碱液后，部分区域形成反平行链结构，形成纤维素Ⅱ型；在纤维素Ⅰ型向纤维素Ⅱ型转变的过程中，纤维扭转，同时由于溶胀现象，纤维活动空间变大，纤维之间便会发生缠绕，形成相勾连的结构，使得纤维之间具有物理强相互作用，且这种作用不依赖于氢键，不会被水分子侵袭破坏，从而赋予纤维素纸张耐水性能。
优选地，在碱液中处理的时间为30秒至48小时，进一步优选地，在碱液中处理的时间为1分钟至2小时。
可选地，在碱液中处理分2～5次进行，即，处理一定时长后，取出，再浸入碱液处理，如此反复；优选地，反复3次进行处理。分次进行处理可以使得纤维形态扭转、弯曲更充分，增强纤维间勾连作用，使纤维素纸具备更好的耐水性能。
优选地，所述碱液的质量百分浓度为15％～28％。
优选地，所述碱液的温度为18℃～32℃。
碱液的温度和浓度直接关系对纤维形态的调整和控制，不适宜的温度和浓度会导致纤维溶胀过高，造成纤维之间的勾连不够典型，无法具备足够的强度，难以实现耐水性能；在预设范围内，纤维的溶胀和扭转达到平衡态，能大大提升耐水纸的耐水性能和强度。碱液的处理时间也关乎耐水性能的赋予，在预设范围内，纤维素的反应能够彻底进行，且不会对纸张的其他性能造成影响。
本发明通过使用温度大于等于8℃、质量百分浓度为10％～35％的碱液对纤维素纸处理5秒至72小时，能够对纤维空间形态进行调控，使纤维之间能相互编织、锁扣、勾连，形成强有力的物理连接，这样的物理强相互作用并不依赖于纤维间的羟基结合，因此不会受到水分子侵袭的影响。本发明制备的耐水纸不会因为在水中氢键被破坏从而失去强度，可以实现在水环境中工作，并具备较好的湿强度，此外，在浸湿后，较普通的纤维素纸具备更优秀的耐磨强度、耐破度、撕裂度、耐折度以及柔软度；最重要的是，制备过程中未引入其他疏水性的添加剂，也不需要通过对纤维分子结构进行化学改性，引入新的耐水基团，对环境友好，生物兼容性良好，且减少了原材料的限制，大大降低了生产成本，提高了生产效率，并兼具优越的性能和广阔的使用场景，具备良好的商业前景。
在一个具体示例中，纤维素纸由结晶度大于等于30％的α-纤维素纤维制备。当所用纤维中α-纤维素的结晶度大于30％时，纤维结构足够紧密，此时纤维处理后的弯曲形态变化将更明显。结晶度过低的纤维在本发明浓度范围内的碱液中容易溶解，这是因为低结晶度的纤维之间距离较远，当纤维间的氢键被碱液破坏后由于无法再度形成强氢键，会造成失去强氢键的部分纤维溶解，无法很好地制备耐水纸；而结晶度大于等于30％的纤维，纤维间的氢键会被碱液破坏，但是由于纤维间的距离较近，当洗去碱液后，近距离的纤维之间又能形成强氢键，此时，纤维素也从纤维素I型变成纤维素II型，纤维素II型呈反平行结构，在纤维素Ⅰ型向纤维素Ⅱ型转变的过程中，纤维扭转，同时由于溶胀现象，纤维活动空间变大，纤维之间便会发生缠绕，形成相勾连的结构，使得纤维之间具有物理强相互作用，且这种作用不依赖于氢键，不会被水分子侵袭破坏，从而赋予纤维素纸张耐水性能。
在一个具体示例中，碱液为氢氧化钠溶液、氢氧化钾溶液、氢氧化锂溶液、氢氧化钙溶液、氨水中的至少一种。
在一个具体示例中，优选地，氢氧化钠溶液为氢氧化钠水溶液，氢氧化钠水溶液的质量百分浓度为18％～25％。
在一个具体示例中，纤维素纸的纤维直径为1μm～250μm，优选地，纤维素纸的纤维直径为5μm～180μm，进一步优选地，纤维素的纤维直径为10μm～50μm。在预设直径范围内的纤维能更好地适应本发明中的碱液浓度及处理时间，在获得耐水性的同时，不会损伤纤维本身的强度。
在一个具体示例中，纤维素纸的纤维来源为木本植物、藤本植物、草本植物中的至少一种。
在一个具体示例中，用水清洗的步骤前，用酸进行中和，在水洗前用酸进行中和，能更好地去除碱液残留。
在一个具体示例中，用水清洗的步骤后，将样品进行保压。
在一个具体示例中，保压的压力为0.01MPa～20MPa，保压的时间为0.1h～24h。将耐水纸进行保压，能使得纸张更加平整和容易干燥，方便后续处理。
本发明的另一方面，还提供了一种纤维素耐水纸，纤维素耐水纸的纤维之间互相勾连，且纤维素耐水纸不含疏水性添加剂。
在一个具体示例中，纤维素耐水纸由前述制备方法制备得到。制得的纤维素耐水纸不含疏水性添加剂，环境友好易分解，在水中完全浸没1小时后，湿强度最高可达15.1MPa，具有广阔的应用前景。
以下结合具体实施例和对比例对本发明做进一步详细的说明。可理解，以下实施例所用的仪器和原料较为具体，在其他具体实施例中，可不限于此。
实施例1
将木材中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为25℃的氢氧化钠水溶液中，反应1分钟后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约15.0MPa。
实施例2
将木材中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为30％、温度为25℃的氢氧化钠水溶液中，反应1分钟后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约9.7MPa。
实施例3
将木材中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为10％、温度为25℃的氢氧化钠水溶液中，反应1分钟后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的 试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约8.9MPa。
实施例4
将木材中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为25℃的氢氧化钠水溶液中，反应48小时后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约14.1MPa。
实施例5
将木材中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为25℃的氢氧化钾水溶液中，反应1分钟后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约8.3MPa。
实施例6
将竹子中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为230μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为25℃的氢氧化钠水溶液中，反应1分钟后取出， 用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约7.6MPa。
实施例7
将藤本植物中的木质素去除，提取得到α-纤维素结晶度为46％的微米纤维素纤维，纤维直径约为10μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为25℃的氨水中，反应0.5小时后取出，用适量的酸中和后，用水清洗样品三次，去除残余的化学药品，然后将样品置于压机中，在压力为4MPa下，保压0.5小时，然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约7.7MPa。
实施例8
将棉纤维中的木质素去除，提取得到α-纤维素结晶度为85％的微米纤维素纤维，纤维直径约为20μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为35％、温度为25℃的氢氧化钾水溶液中，反应10分钟后取出，用适量的酸中和后，用水清洗样品三次，去除残余的化学药品；将以上步骤重复三次，然后将样品置于压机中，在压力为2MPa下，保压24小时，然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约15.1MPa。
实施例9
将稻草中的木质素去除，提取得到α-纤维素结晶度为47.6％的微米纤维素纤维，纤维直径约为25μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为15％、温度为25℃的氢氧化钠水溶液中，反应48小时后取出，用适量的酸中和后，用水清洗样品三次，去除残余的化学药品；将以上步骤重复三次，然后将样品置于压机中，在压力为0.5MPa下，保压0.5小时然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约10.9MPa。
实施例10
将稻草中的木质素去除，提取得到α-纤维素结晶度为47.6％的微米纤维素纤维，纤维直径约为25μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为15％、温度为15℃的氢氧化钠水溶液中，反应48小时后取出，用适量的酸中和后，用水清洗样品三次，去除残余的化学药品；将以上步骤重复三次，然后将样品置于压机中，在压力为0.5MPa下，保压0.5小时然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约8.9MPa。
实施例11
将稻草中的木质素去除，提取得到α-纤维素结晶度为47.6％的微米纤维素纤维，纤维直径约为25μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为15％、温度为35℃的氢氧化钠水溶液中，反应48小时后取出，用适量的酸中和后，用水清洗样品三次，去除残余的化学药品；将以上步骤重 复三次，然后将样品置于压机中，在压力为0.5MPa下，保压0.5小时然后将样品干燥，得到纤维素耐水纸材料；将纤维素耐水纸材料裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约9.5MPa。
对比例1
将木材中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为7％、温度为25℃的氢氧化钠水溶液中，反应1分钟后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将耐水纸裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约0.1MPa。
对比例2
将木材中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为5℃的氢氧化钠水溶液中，反应1分钟后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将耐水纸裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约5.6MPa。
对比例3
将木材中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为25℃的氢氧化钠水溶液中，反应3秒后取出，用适 量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将耐水纸裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约6.3MPa。
对比例4
将木材中的木质素去除，提取得到α-纤维素结晶度为20％的微米纤维素纤维，纤维直径约为15μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为25℃的氢氧化钠水溶液中，反应1分钟后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将耐水纸裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约1.5MPa。
对比例5
将竹子中的木质素去除，提取得到α-纤维素结晶度为50％的微米纤维素纤维，纤维直径约为260μm，将提取得到的纤维制备成纤维素纸，然后将其置于质量百分浓度为18％、温度为25℃的氢氧化钠水溶液中，反应1分钟后取出，用适量的酸充分中和后，用水清洗样品三次，去除残余的氢氧化钠和酸，然后将样品干燥，得到纤维素耐水纸材料；将耐水纸裁成10cm*1.5cm的试条，浸没水中1小时后取出，用万能力学试验机测试试条的湿抗拉强度，约3.3MPa。
表征测试：
将实施例1中制备的纤维素耐水纸与未经碱液浸泡处理的普通纤维素纸另外进行耐磨强度测试、耐破度测试、撕裂度测试、耐折度测试以及柔软度测试，测试步骤如下：
(1)耐磨强度测试
纸张的耐磨度是指纸张在阻力下所能抵抗表面磨损的一种性能。本实验中所用的仪器是美国厂家生产的Taber Abraser 5135型号纸张耐磨度测试仪，其工作方式简图如图6(a)所示。
将试样纸张裁成直径为10cm的圆形，放置固定在耐磨度测试仪上，选择摩擦头的荷重，启动转台，记录纸张磨破时所转的圈数。湿耐磨性能的测试是将试样纸在水中浸泡1小时后取出，再按上述步骤进行耐磨性能测试，根据纸张磨破时所转圈数的多少来比较纸张的耐磨性能。测试多个试样以减小实验误差。
(2)耐破度测试
纸张的耐破度是指，单位面积的纸在破裂前所能承受的最大压力，通常用KPa表示。本文选用PTI F18533型纸板耐破度仪进行测试，其工作方式简图如图6(b)所示。将纸样裁成100mm×100mm的方形，放置样品后，启动电机，记录样品破裂时的压力表数值。湿样品处理方式同耐磨强度测试一致，测试方法与干样品相同。每个样品取3个测试点，测试多个样品以减小误差。
耐破度计算公式如下
Figure PCTCN2022094826-appb-000001
式中，X代表耐破指数(kPa﹒m 2/g)，p代表耐破度(kPa)，g代表纸样定量(g/m 2)。
(3)撕裂度测试
纸张撕裂度是指在指定条件下，将预先切口的纸，撕至一定长度所需力的平均值。根据埃尔门多夫方法，选用瑞典公司生产的L&W 009撕裂度测试仪进 行抗撕裂性测试，其工作方式简图如图6(c)所示。将纸样裁成75mm×65mm的长方形，把纸片夹好，用仪器上的刀具开出一个整齐的切口。指针与停止器接触，用手速迅速压住摆的停止器，待摆从最远处返回到接近起始位置时，轻轻地停住摆，读取显示的数值。湿样品处理方式同耐磨强度测试一致，测试方法与干样品相同。测试多个样品以减小误差。
撕裂指数的计算公式如下：
Figure PCTCN2022094826-appb-000002
式中，X代表撕裂指数(mN·m 2/g)，a代表撕裂度(mN)，g代表纸样定量(g/m 2)。
(4)耐折度测试
纸的耐折度是指纸张在受到一定张力的条件下往复折叠固定角度直到折断时的次数，以往复折叠的次数表示。本实验中选用MIT/U21B耐折度仪进行试验，其工作方式简图如图6(d)所示。将纸样裁成15mm×150mm的长条，调节耐折度仪的弹簧张力和折叠头，使缝口对齐。调好张力指示器，把纸样夹好，而后锁紧张力杆，使纸样夹紧。松开张力杆锁，然后开始进行测试，纸样开始折叠，直到纸样断裂，记录仪器所显示的折叠次数。湿样品处理方式同耐磨强度测试一致，测试方法与干样品相同。对比折叠次数的大小，来比较纸张耐折性能的优异。测试多个样品以减小误差。
(5)柔软度测试
在指定条件下，当柔软度仪板状测头将试样压入夹缝中一定深度(约8mm)时，试样本身的抗弯曲力和试样与缝隙处摩擦力的最大矢量之和称为柔软度， 以mN表示。柔软度越小，说明纸样越柔软。本实验采用蓝博仪器公司生产的LB-R1000型电脑柔软度仪，将纸样裁成100mm×100mm的大小进行测试，读取显示器上的测量值，横、纵方向应分别测试10个数据。湿样品处理方式同耐磨强度测试一致，测试方法与干样品相同。
上述表征测试结果分别见图7～11。
从各实施例可以看出，本发明的方案制备的耐水纸具备良好的湿强度，在水中浸泡一小时后，湿强度最高可达15.1MPa，且较未经处理的普通纤维素纸，在浸湿后具备更优异的耐磨强度、耐破度、撕裂度、耐折度以及柔软度。
从对比例1可以看出，当碱液浓度下降至7％时，湿强度陡降至0.1MPa，从对比例2可以看出，当温度降至5摄氏度时，湿强度也下降至5.6MPa，这是因为过低的浓度和反应温度不足以使纤维发生溶胀和扭转，无法制备耐水纸；对比例3中，反应时间过短，反应不充分，纤维之间形成的勾连作用不够强，因此湿强度也仅有6.3MPa；对比例4中，纤维素的结晶度不足30％，纤维结构不够紧密，纤维之间距离较远，在本发明的碱液浓度下，当纤维间的氢键被破坏后无法再度形成强氢键，造成失去强氢键的部分纤维溶解，从而制得的纸张湿强度大幅下降；对比例5中，纤维直径过大，导致纤维的溶胀后扭转受限，因此纤维间的勾连作用也不够牢固，湿强度仅有3.3MPa。
以上所述实施例的各技术特征可以进行任意的组合，为使描述简洁，未对上述实施例中的各个技术特征所有可能的组合都进行描述，然而，只要这些技术特征的组合不存在矛盾，都应当认为是本说明书记载的范围。
以上所述实施例仅表达了本发明的几种实施方式，其描述较为具体和详细，但并不能因此而理解为对发明专利范围的限制。应当指出的是，对于本领域的 普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干变形和改进，这些都属于本发明的保护范围。因此，本发明专利的保护范围应以所附权利要求为准。

Claims (11)

  1. 一种纤维素耐水纸的制备方法，其特征在于，包括以下步骤：
    将纤维素纸置于碱液中处理5秒至72小时，取出后用水清洗，然后干燥；所述碱液的质量百分浓度为10％～35％，所述碱液的温度大于等于8℃，且制备过程不引入疏水性添加剂；
    其中，所述纤维素纸由结晶度大于等于30％的α-纤维素纤维制备，所述碱液为氢氧化钠溶液、氢氧化钾溶液以及氢氧化锂溶液中的至少一种。
  2. 根据权利要求1所述的制备方法，其特征在于，所述碱液的质量百分浓度为15％～28％，所述碱液的温度为18℃～32℃。
  3. 根据权利要求1所述的制备方法，其特征在于，所述氢氧化钠溶液为氢氧化钠水溶液，所述氢氧化钠水溶液的质量百分浓度为18％～25％。
  4. 根据权利要求1所述的制备方法，其特征在于，所述纤维素纸的纤维直径为1μm～250μm。
  5. 根据权利要求1所述的制备方法，其特征在于，所述纤维素纸的纤维直径为10μm～50μm。
  6. 根据权利要求1所述的制备方法，其特征在于，所述纤维素纸的纤维直径为10μm～50μm。
  7. 根据权利要求1～6任一项所述的制备方法，其特征在于，所述纤维素纸的纤维来源为木本植物、藤本植物、草本植物中的至少一种。
  8. 根据权利要求1～6任一项所述的制备方法，其特征在于，所述用水清洗的步骤前，用酸进行中和。
  9. 根据权利要求1～6任一项所述的制备方法，其特征在于，所述用水清洗的步骤后，将样品进行保压。
  10. 根据权利要求9所述的制备方法，其特征在于，所述保压的压力为0.01 MPa～20MPa，所述保压的时间为0.1h～24h。
  11. 一种纤维素耐水纸，其特征在于，由权利要求1～10任一项制备得到。
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040074615A1 (en) * 2002-10-16 2004-04-22 Nguyen Xuan Truong Process for preparing microcrystalline cellulose
CN1535343A (zh) * 2001-07-24 2004-10-06 日本制纸株式会社 膨松纸浆、其制造方法、使用该膨松纸浆的加工纸或多层纸
CN107653744A (zh) * 2017-09-12 2018-02-02 成都新柯力化工科技有限公司 一种超疏水纸及其制备方法
CN111925743A (zh) * 2020-08-18 2020-11-13 福建农林大学 一种生物质浸渍胶膜纸及其制备方法
CN112301794A (zh) * 2020-10-23 2021-02-02 杭州众材科技有限公司 一种提高表面疏水性的纸质保护方法
CN113026420A (zh) * 2021-03-26 2021-06-25 南京大学 纤维素耐水纸及其制备方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08120597A (ja) * 1994-10-20 1996-05-14 Mitsubishi Paper Mills Ltd リサイクル可能な耐水性透明紙および窓開き封筒用フィルム
CN102251404B (zh) * 2011-05-09 2013-03-27 张家港耐尔纳米科技有限公司 一种仿麻棉纱线的制备方法
CN108708219B (zh) * 2018-06-01 2020-11-17 中国人民大学 一种利用含纳米氢氧化钙的亚临界流体对纸质材料进行脱酸的方法
CN110607715A (zh) * 2019-09-28 2019-12-24 华南理工大学 一种无氟防油纸及其制备方法与应用

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1535343A (zh) * 2001-07-24 2004-10-06 日本制纸株式会社 膨松纸浆、其制造方法、使用该膨松纸浆的加工纸或多层纸
US20040074615A1 (en) * 2002-10-16 2004-04-22 Nguyen Xuan Truong Process for preparing microcrystalline cellulose
CN107653744A (zh) * 2017-09-12 2018-02-02 成都新柯力化工科技有限公司 一种超疏水纸及其制备方法
CN111925743A (zh) * 2020-08-18 2020-11-13 福建农林大学 一种生物质浸渍胶膜纸及其制备方法
CN112301794A (zh) * 2020-10-23 2021-02-02 杭州众材科技有限公司 一种提高表面疏水性的纸质保护方法
CN113026420A (zh) * 2021-03-26 2021-06-25 南京大学 纤维素耐水纸及其制备方法

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