Degradable cellulose acetate fiber, tow and preparation method and application thereof

Abstract

The degradable cellulose acetate fiber is composed of a polymer, the polymer comprises cellulose acetate and organic alkaline substances, and the organic alkaline substances are uniformly distributed in the cellulose acetate; the preparation method of the degradable cellulose acetate fiber comprises the following steps: dissolving cellulose acetate in a solvent to form a first homogeneous system; the method comprises the following steps: dissolving organic alkaline substances in water; adding a solvent into the aqueous solution obtained in the previous step to form a second homogeneous system; and adding the second homogeneous system into the first homogeneous system to form a uniform degradable polymer composition, mixing and uniformly distributing the uniform degradable polymer composition to form a third uniform dispersion system, and spraying the slurry of the third uniform dispersion system through a spinneret orifice and subsequently drying to obtain the degradable cellulose acetate fiber.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical materials and relates to a degradable cellulose acetate fiber, a tow, and a preparation method and application thereof. Background Art

[0002] Cellulose diacetate is a bio-based acetate. Studies have shown that its biodegradability under natural conditions needs to be further improved. The biodegradation rate of cellulose diacetate mainly depends on the change in the degree of acetyl substitution, and many papers have reported on this. For example, in the paper J.Appl.Polym.Sci.1993,50,1739-1746, the authors 14 The C-labeling method was used to study the CO2 release of cellulose acetate with different degrees of substitution. The article compared the CO2 release of cellulose acetates with DS of 1.85, 2.07, and 2.57 under aerobic composting conditions. The authors found that the lower the DS, the higher the CO2 release, indicating that the lower the DS, the more favorable it is for biodegradation. In the paper Appl. Biochem. Biotechnol. 1992, 34-35, 725-736, the authors placed cellulose acetates with DSs ranging from 0.82 to 2.40 in a culture medium for 98 days. The comparison revealed that cellulose acetates with DSs less than 1.25 degraded rapidly, while cellulose acetates with DSs between 1.25 and 2.40 degraded more slowly as the DS increased. In the paper J. Environ. Polym. Degrad. 1996, 4, 179-195, the authors mixed cellulose acetates with DS2.0 and DS2.5 in different proportions to prepare optical plastics. The study showed that the higher the DS2.0 content, the better the degradation performance of the optical plastic. The authors also studied the significant improvement in the degradation performance of cellulose acetate by adding PEG (Mw 400). US Patent 5,512,230 reported that by increasing the moisture content of the acetone slurry system, cellulose acetate with DS1.9-2.2 could be thoroughly mixed and uniformly spun with conventional cellulose acetate with DS2.45, ultimately improving the degradation performance of the yarn using low-substitution cellulose acetate. Therefore, the degree of substitution of cellulose acetate is a crucial factor in its biodegradation. Both aerobic and anaerobic microorganisms can degrade cellulose diacetate in the environment. Improving the biodegradability of cellulose diacetate meets current environmental requirements. Research on methods to accelerate the reduction of the degree of substitution of cellulose diacetate has important application value.

[0003] In the prior art, various substances that promote the accelerated degradation of cellulose diacetate are added, such as inorganic compounds calcium oxide and magnesium oxide; inorganic acidic substances containing phosphorus and sulfur elements, boric acid, hydrochloric acid, nitric acid, sulfuric acid, etc. and their salt compounds; and some organic acids, such as ascorbic acid, cinnamic acid, citric acid, folic acid, niacin, succinic acid, malic acid, tartaric acid, etc. Although the addition of the above substances has a certain effect on promoting degradation, it also has its disadvantages. For example, patent publication number CN114981311A discloses a degradable cellulose ester product, which improves the degradability of cellulose ester by adding alkaline materials, enzyme materials, or a combination thereof to the product, and the alkaline materials used include at least one of calcium oxide, calcium hydroxide, magnesium hydroxide, magnesium oxide, or a combination thereof; patent publication number CN112375259A discloses a polymer composition containing an alkaline additive, a method and an article containing the polymer composition, wherein the alkaline additive includes alkaline earth metal oxide, ZnO and alkaline Al2O3, MgO, Mg(OH)2, MgCO3, CaO, Ca(OH)2, etc., wherein the selected magnesium oxide is insoluble in water or acetone water phase and agglomerates, resulting in many disadvantages in practical applications. The disadvantages of the prior art include: poor solubility of additives resulting in excessive local acidity or alkalinity, which has an adverse effect on the shelf life of acetate fiber products; poor solubility of added substances, resulting in agglomeration, making it difficult to disperse evenly in the system and unable to play an effective role; adding magnesium oxide to acetate fiber acetone slurry will cause acetone to undergo a condensation reaction to produce mesityl oxide, resulting in the generation of new substances in the acetone slurry system, which has an adverse effect; and the addition of calcium oxide has excessive alkalinity and strong water absorption, which has a significant adverse effect on the quality of the tow product during storage and use. Summary of the Invention

[0004] The present invention aims to provide a biodegradable cellulose acetate polymer, a preparation method thereof, and the prepared products, such as tows and fibers, which utilize nitrogen-containing alkaline substances to catalyze the rapid deacetylation of cellulose acetate to reduce its degree of substitution, thereby indirectly helping to improve the biodegradability of cellulose acetate.

[0005] The solution of the present invention is:

[0006] A cellulose diacetate degradable polymer, at least a portion of which comprises cellulose diacetate and a nitrogen-containing alkaline substance, wherein the nitrogen-containing alkaline substance can reduce the degree of substitution of the cellulose diacetate, and the cellulose diacetate degradable polymer composition is uniformly distributed.

[0007] The nitrogen-containing alkaline substance can react with cellulose acetate to remove the acetyl group, thereby reducing the degree of substitution of cellulose diacetate to the range of 1.8-2.2.

[0008] Optionally, the organic alkaline substance includes nitrogen-containing alkaline substances, including acidic amino acids, basic amino acids, polypeptides (degree of polymerization less than 100), 1-acetylguanidine, guanidine, quinine, 1-tert-butylcarbonylguanidine, tert-butylguanidine, polyamide (degree of polymerization less than 100), polyhydrazide-PEG-hydrazide (degree of polymerization less than 200), naphthalene, 1,8-bisdimethylaminonaphthalene, Schiff base, pyridine, pyrrole, imidazole, pyrazine, pyrimidine, pyridazine, indole, preferably basic amino acids and 1-acetylguanidine, more preferably one or more of arginine and lysine. When the degree of polymerization of polypeptides, polyamides, and polyhydrazide-PEG-hydrazide is too high, their solubility in water is reduced, which is not conducive to releasing their acidity and alkalinity.

[0009] Optionally, the pH value of the nitrogen-containing alkaline substance itself ranges from 8.5 to 14.0, preferably from 9.0 to 11.0. Lysine (pH 9.8) and arginine (pH 10.5) are relatively alkaline, and their mass ratio in the cellulose polymer is 0.3 to 10.0%, preferably from 1.0 to 7.0%. Optionally, the uniform distribution refers to the uniform distribution of the organic alkaline substance and cellulose diacetate in the cellulose polymer. This statement uses specific indicators to measure the definition of uniform distribution. Of course, the more organic alkaline substance is added, the more difficult it is to form a uniform distribution system.

[0010] Optionally, the nitrogen-containing alkaline substance is arginine, and the mass ratio of arginine in the cellulose polymer is 0.3-10.0%, preferably 1.0-7.0%.

[0011] Optionally, the cellulose diacetate degradable polymer is at least in the form of tows and fibers.

[0012] A method for improving the degradation performance of cellulose diacetate, comprising adding a nitrogen-containing alkaline substance to cellulose diacetate to form any of the above-described cellulose diacetate degradable polymer compositions, wherein the cellulose diacetate degradable polymer composition is uniformly distributed, and the nitrogen-containing alkaline substance is used to deacetylate the cellulose diacetate to reduce its degree of substitution, thereby improving the degradability of the cellulose diacetate.

[0013] The degradation performance of cellulose diacetate is directly related to its degree of substitution and degree of polymerization, especially its degree of substitution directly determines the degradation rate. If the degree of substitution of cellulose diacetate is reduced to the range of 1.8-2.2, its degradation rate will be significantly improved in the natural environment. In the prior art, inorganic base magnesium oxide is used, but magnesium oxide is insoluble in acetone slurry and insoluble in water, resulting in it being trapped during the slurry filtration process and having little actual effect. The present invention uses nitrogen-containing organic matter, such as amino acids, which are very water-soluble. In the specific process, the amino acids are dissolved in water, and then acetone is sprayed into the amino acid aqueous solution until the system begins to become slightly turbid. While fully stirring the amino acid solution, the vinegar acetone slurry is slowly added to the above system to form a uniformly distributed cellulose diacetate polymer composition. The amino acids will not be trapped or will be trapped in small amounts during the slurry filtration process, and can fully play a role compared to magnesium oxide.

[0014] Preferably, the present invention utilizes the activity of natural alkaloids, preferably amino acids, to deacetylate cellulose acetate in water at room temperature, reducing its degree of substitution to 1.8-2.2 (the time varies depending on the amount of reactants added), significantly improving its degradation performance. Furthermore, natural alkaloids have advantages such as being human-friendly, odorless, water-soluble, naturally derived, thermally stable, and free of side reactions in acetone solutions, resulting in excellent catalytic effects.

[0015] Prior art primarily utilizes the Brönsted acid-base theory, using inorganic bases to reduce the degree of substitution of cellulose acetate. For example, magnesium oxide reacts with water to form magnesium hydroxide, and the ester bonds of cellulose acetate undergo an acid-base neutralization reaction under alkaline conditions to form magnesium acetate. In contrast, the present invention innovatively utilizes the Lewis acid-base theory, utilizing human-friendly natural compounds, natural alkaloids, particularly basic amino acids, to reduce the degree of substitution of cellulose acetate by leveraging the lone electron pair properties of the amino group.

[0016] Prior art degradable cellulose diacetate films utilize inorganic magnesium oxide to promote the degradation of cellulose acetate. However, because magnesium oxide is insoluble in water and acetone, this degradable cellulose acetate film exhibits significant particle size, resulting in an uneven system and poor slurry clarity and haze. In contrast, the method of the present invention provides a uniformly distributed degradable cellulose acetate polymer composition. Therefore, the amount of organic alkaline substance added, along with the definition of uniform distribution based on this amount, is described herein. Considering the presence of cellulose triacetate, a larger amount may be added for degradation. The mass ratio of the organic alkaline substance to the cellulose polymer is 0.2-14.0%, preferably 1.0-7.0%.

[0017] Cellulose acetate is dissolved in one or more of the following at 25°C: acetone, methyl butyl ketone, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, ethyl acetate, ethyl lactate, ethyl acetate:ethanol = 75:25, 1-methyl-2-pyridine, DMF, DMSO, and chloroform to form a first homogeneous phase, preferably ethyl acetate, ethanol, acetone, methyl butyl ketone, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone, with acetone being more preferred. An organic alkaline substance is first dissolved in water at 25°C, preferably arginine, lysine, or 1-acetylguanidine, with arginine being more preferred. Acetone is then added (1-10 mL / min) to an aqueous arginine solution at 25°C to form a second homogeneous phase (W acetone:W water = 1.0-5.0). The second homogeneous system is added to the first homogeneous system to form a uniformly distributed acetone slurry of the degradable polymer composition. The acetone slurry of the composition is spun through a porous spinneret and the solvent is volatilized and separated by hot air (50-100°C). After curling, drying, swinging and packaging, a degradable tow is prepared, thereby obtaining a degradable cellulose acetate tow.

[0018] Taking into account the dissolution variability of cellulose acetates of varying degrees of substitution, the polymer acetone slurry has a transmittance range of 65.0%-92.0%, preferably 80.0%-90.0%, and a haze (%) range of 3.0% to 20.0%, preferably 3.0% to 13.0%. Haze and transmittance are measured using an UltroScan spectrocolorimeter. The acetone slurry is filtered through a 0.45 μm filter membrane. The amino acid concentration in the filtered slurry is greater than 95%.

[0019] A method for preparing degradable cellulose acetate tow comprises the following steps:

[0020] 1. Dissolve cellulose acetate in acetone at 25°C, with the ratio of cellulose acetate to acetone in the first homogeneous system being 1:1.5-3.5.

[0021] 2. Completely dissolving an alkaline substance in water at 25° C.; the alkaline substance is at least one of arginine, lysine, histidine, glycine, alanine, valine, leucine, isoleucine, methionine, proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, and glutamic acid; then adding acetone to the aqueous solution of the alkaline substance without precipitation of particles to form a second homogeneous system, wherein the ratio of acetone to water in the second homogeneous system is 1:1.0-5.0;

[0022] 3. Add the second homogeneous phase system to the first homogeneous phase system through a syringe pump (flow rate is 1-10 mL / min), stirring the first homogeneous phase system continuously while adding until the second homogeneous phase system is added and continue stirring for 3-8 hours to form a third uniform dispersion system;

[0023] 4. The third uniformly dispersed system is directly spun through a porous spinneret under pressure without being filtered, and is then crimped, dried, swung, and packaged to form a degradable cellulose acetate tow.

[0024] The configuration of the second homogeneous system and the third homogeneous dispersion system is the process of optimizing the production process. The second homogeneous system is configured in two steps. The addition of the second homogeneous system to the first homogeneous system using a syringe pump is also an optimization of the feeding process. These optimization processes are all aimed at preventing the precipitation of amino acids in the final third homogeneous dispersion system to form particles, which would have an adverse effect on the subsequent spinning process (such as clogging the spinning holes). If amino acids precipitate, they may be intercepted by the filtration process in the pre-spinning process, resulting in a decrease in their actual remaining content in the silk and reducing the effectiveness of their alkalinity.

[0025] The present invention utilizes a nitrogen-containing alkaline substance to rapidly deacetylate cellulose acetate and reduce its degree of substitution, thereby improving the degradation performance of cellulose acetate and products containing the same. The nitrogen-containing alkaline substance and amino acid used in the present invention are uniformly dissolved in the slurry and are not filtered by slurry filters. This presents a significant advantage over existing technologies (e.g., adding magnesium oxide to the slurry). Because magnesium oxide is insoluble in the slurry, existing technologies that add magnesium oxide to the slurry risk agglomeration and being trapped by slurry filters. The present invention avoids this risk.

[0026] Furthermore, in order to prevent amino acids from precipitating in large pieces in the slurry, the present invention can ensure that the amino acids are precipitated below the micron level and will not aggregate or be trapped by filtration, thereby achieving the maximum effect.

[0027] The existing technology is to add additives to the slurry without considering whether it can be evenly dispersed and dissolved. The method of the present invention enables the amino acid to be dissolved and dispersed as evenly as possible, and to be evenly dispersed in fine particles without affecting subsequent filtration.

[0028] In addition, in addition to cellulose acetate with a degree of substitution of 2.45, the present invention is also applicable to the degradation of triacetyl cellulose with a degree of substitution of 3.0.

[0029] A degradable cellulose acetate fiber comprises cellulose acetate and an organic alkaline substance, wherein the organic alkaline substance is uniformly distributed in the cellulose acetate. The mass ratio of the organic alkaline substance in the degradable cellulose acetate material is 0.2-14.0%. The organic alkaline substance includes nitrogen-containing alkaline substances, amine polymers, amide polymers, heterocyclic compounds, etc., and the pH value of the organic alkaline substance ranges from 8.5 to 14.0. The degradable property refers to that the alkaline substance can reduce the degree of substitution of cellulose acetate to 1.8-2.2. The present invention includes degradable cellulose acetate polymers in the form of tows, fibers, etc. The present invention also discloses a method for preparing uniformly distributed degradable cellulose acetate fibers. The uniform distribution means that the transmittance of the cellulose acetate fiber slurry used to prepare the cellulose acetate fibers is 65.0%-92.0%, and the haze (Haze%) ranges from 2.0% to 20.0%. The uniform distribution of organic alkaline substances in the fibers can be obtained by measuring the uniformity of nitrogen distribution using SEM-EDS (the diameter of the fiber circumscribed concentric circles is 1.0-200 μm). BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a diagram showing the distribution of amino acids in the fiber of Example 1 detected by EDS.

[0031] Figure 2 This is a diagram showing the distribution of amino acids in the fiber of Example 2 detected by EDS.

[0032] Figure 3 This is a diagram showing the distribution of amino acids in the fiber of Example 3 detected by EDS. DETAILED DESCRIPTION

[0033] The present invention is further described with reference to the following examples.

[0034] At 25°C, 200g of cellulose acetate was dissolved in 503g of acetone to form a first homogeneous phase. 8g of an organic alkaline substance was completely dissolved in 27g of water at 25°C. 10g of acetone was then added to the aqueous solution of the organic alkaline substance without particle precipitation to form a second homogeneous phase. The second homogeneous phase was then added to the first homogeneous phase via a syringe pump and stirred for 5 hours to form a uniform biodegradable polymer composition. Haze (%) and transmittance were measured using an UltroScan spectrophotometer. The concentration of alkaline substances in the slurry was tested by filtration using a 0.45μm Whatman filter membrane. SEM-EDS was used to determine the uniformity of the C / O / N element distribution in the amino acids. GC (gas chromatography) was used to determine the acetate content in the polymer composition. The degree of reduction in the degree of substitution of the cellulose acetate was then calculated. Separating the solvent from the polymer composition can produce a biodegradable cellulose acetate polymer product in the form of tows or fibers.

[0035] Comparative Example

[0036] 200g of cellulose acetate was dissolved in 503g of acetone at 25°C to form a first homogeneous phase. 8g of an alkaline substance was dissolved in 27g of water at 25°C at 25°C. 10g of acetone was then added to the aqueous alkaline solution to form a second homogeneous phase. This second homogeneous phase was then added to the first homogeneous phase via a syringe pump (at a flow rate of 1mL / min) and stirred for 5 hours to form a degradable polymer composition. The composition was then tested for haze, transmittance, and residual alkaline content. The polymer composition was then pressure-spun through a spinneret, and the solvent was separated to form degradable cellulose acetate fibers. The results are shown in Table 1.

[0037] Table 1: Properties of polymer slurry containing inorganic base and changes in fiber substitution degree

[0038]

[0039] Note: Bound acid content = (6000*degree of substitution DS) / (162 + 42*degree of substitution DS); the bound acid content is determined by GC detection and calculation.

[0040] The haze, transmittance, and alkaline residue of the above-mentioned polymer composition slurry were tested. The haze of the magnesium oxide system was 64.2%, the transmittance was 72.3%, and the alkaline residue of the system after slurry filtration was 61%; the haze of the calcium oxide system was 60.7%, the transmittance was 76.7%, and the alkaline residue of the system after slurry filtration was 66%, indicating that its uniform distribution in the system was poor, and the alkaline substances formed particles that were easily filtered and retained, resulting in only 61% and 66% of the alkaline substances remaining after filtration.

[0041] Example 1

[0042] 200g of cellulose acetate was dissolved in 380g of acetone at 25°C to form a first homogeneous system; 2.4g of arginine (pH 10.76), an organic alkaline substance, was completely dissolved in 80g of water at 25°C, and then 80g of acetone was added to the aqueous solution of the alkaline substance arginine in the system without particle precipitation to form a second homogeneous system. The second homogeneous system was added to the first homogeneous system via a syringe pump (flow rate of 10mL / min) and stirred uniformly for 5 hours to form a uniform degradable polymer composition with a haze of 12.7% and a transmittance of 86.1%. After the slurry was filtered, the alkaline substance in the system remained at 97.1%. The third uniformly dispersed system was spun through a spinneret under pressure and air-dried at 50°C to form degradable cellulose acetate fiber with a fiber denier of 9.0D, a fiber circumscribed concentric circle diameter of 120μm, and a specific surface area of 0.80m 2 / g, the degree of substitution of the fiber decreased from 2.45 to 2.35 within 130 days. SEM-EDS detection of amino acid distribution in cellulose Figure 1 shown.

[0043] Example 2

[0044] 200g of cellulose acetate was dissolved in 503g of acetone to form a first homogeneous system; 4.8g of arginine (pH 10.76), an organic alkaline substance, was completely dissolved in 27g of water at 25°C. 10g of acetone was then added to the aqueous solution of the alkaline substance in the system without particle precipitation to form a second homogeneous system. The second homogeneous system was added to the first homogeneous system via a syringe pump (flow rate of 5mL / min) and stirred uniformly for 8h to form a uniform degradable polymer composition with a haze of 9.6% and a transmittance of 84.4%. After slurry filtration, the alkaline substance in the system remained at 97.6%. The third uniformly dispersed system was spun through a spinneret after applying pressure and air-dried at 100°C to form degradable cellulose acetate fiber with a fiber denier of 5.2D, a fiber circumscribed concentric circle diameter of 73μm, and a specific surface area of 1.1m 2 / g, the degree of substitution of the fiber decreased from 2.44 to 2.27 within 130 days. SEM-EDS detection of amino acid distribution in cellulose Figure 2 shown.

[0045] Example 3

[0046] 200g of cellulose acetate was dissolved in 503g of acetone to form a first homogeneous system; 8.0g of arginine (pH 10.76), an organic alkaline substance, was completely dissolved in 27g of water at 30°C. 10g of acetone was then added to the aqueous solution of the alkaline substance in the system without particle precipitation to form a second homogeneous system. The second homogeneous system was added to the first homogeneous system via a syringe pump (flow rate of 1mL / min) and stirred uniformly for 8 hours to form a uniform biodegradable polymer composition with a haze of 7.9% and a transmittance of 80.0%. After slurry filtration, the alkaline substance in the system remained at 97.3%. The third uniformly dispersed system was spun through a spinneret under pressure and air-dried at 200°C to form biodegradable cellulose acetate fiber with a fiber denier of 8.1D, a fiber circumscribed concentric circle diameter of 111μm, and a specific surface area of 0.86m 2 / g, the degree of substitution of the fiber decreased from 2.45 to 2.1 within 100 days. SEM-EDS detection of amino acid distribution in cellulose Figure 3 shown.

[0047] pass Figure 1-3 It can be found that the SEM-EDS detection of the uniformity of the distribution of amino acid C / O / N elements in the fibers of Examples 1-3 shows that the nitrogen element is uniformly distributed in the diameter of the circumscribed concentric circle.

[0048] Example 4

[0049] 200g of cellulose acetate was dissolved in 503g of acetone to form a first homogeneous system; 0.4g of lysine (pH 8.5), an organic alkaline substance, was completely dissolved in 27g of water at 20°C. Then, 10g of acetone was added to the aqueous solution of the alkaline substance in the system without particle precipitation to form a second homogeneous system. The second homogeneous system was added to the first homogeneous system via a syringe pump (flow rate of 5mL / min) and stirred evenly for 8h to form a uniform degradable polymer composition with a slurry haze of 2.0% and a slurry transmittance of 92%. After the slurry was filtered, 98.0% of the alkaline substance remained in the system. The third uniformly dispersed system was spun through a spinneret under pressure and air-dried at 150°C to form degradable cellulose acetate fiber with a fiber denier of 0.2D, a fiber circumscribed concentric circle diameter of 1.0μm, and a specific surface area of 10.0m 2 / g, and the degree of substitution of the fiber decreased from 2.45 to 2.40 within 100 days.

[0050] Example 5

[0051] 200g of cellulose acetate was dissolved in 503g of acetone to form a first homogeneous system; 28.0g of the organic alkaline substance 1-acetylguanidine (pH 14) was completely dissolved in 27g of water at 70°C, and then 10g of acetone was added to the aqueous solution of the alkaline substance in the system without particle precipitation to form a second homogeneous system. The second homogeneous system was added to the first homogeneous system via a syringe pump (flow rate of 6mL / min) and stirred uniformly for 8 hours to form a uniform degradable polymer composition with a slurry haze of 20.0% and a slurry transmittance of 65%. After the slurry was filtered, the alkaline substance in the system remained at 71%. The third uniformly dispersed system was spun through a spinneret under pressure and air-dried at 120°C to form degradable cellulose acetate fiber with a fiber denier of 30.0D, a fiber circumscribed concentric circle diameter of 200μm, and a specific surface area of 0.01m 2 / g, and the degree of substitution of the fiber decreased from 3.0 to 1.75 within 100 days.

[0052] Example 6

[0053] 200g of cellulose acetate was dissolved in 503g of acetone to form a first homogeneous system; 2.0g of quinine (pH 10.4), an organic alkaline substance, was completely dissolved in 27g of water at 25°C. 10g of acetone was then added to the aqueous solution of the alkaline substance in the system without particle precipitation to form a second homogeneous system. The second homogeneous system was added to the first homogeneous system via a syringe pump (flow rate of 5mL / min) and stirred uniformly for 8h to form a uniform degradable polymer composition with a slurry haze of 3.0% and a slurry transmittance of 85.2%. After the slurry was filtered, 96.8% of the alkaline substance remained in the system. The third uniformly dispersed system was spun through a spinneret under pressure and air-dried at 85°C to form degradable cellulose acetate fiber with a fiber denier of 6.0D, a fiber circumscribed concentric circle diameter of 95μm, and a specific surface area of 0.99m 2 / g, and the degree of substitution of the fiber decreased from 2.43 to 2.20 within 100 days.

[0054] Example 7

[0055] 200g of cellulose acetate was dissolved in 503g of acetone to form a first homogeneous system. 14.0g of 1,8-bis(dimethylaminonaphthalene) (pH 10.0) arginine (organic alkaline substance) was completely dissolved in 27g of water at 55°C. 10g of acetone was then added to the aqueous alkaline solution without particle precipitation to form a second homogeneous system. The second homogeneous system was added to the first homogeneous system via a syringe pump (flow rate of 4mL / min) and stirred for 8h to form a uniform biodegradable polymer composition with a slurry haze of 13.0% and a slurry transmittance of 72.1%. After slurry filtration, 83% of the alkaline substance remained in the system. The third uniformly dispersed system was spun through a spinneret under pressure and air-dried at 130°C to form biodegradable cellulose acetate fiber with a fiber denier of 7.2D, a fiber circumscribed concentric circle diameter of 107μm, and a specific surface area of 0.9m2. 2 / g, and the degree of substitution of the fiber decreased from 2.45 to 2.28 within 100 days.

[0056] The above descriptions and embodiments are provided to facilitate understanding and application of the present invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these contents and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above descriptions and embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should fall within the scope of protection of the present invention.

Claims

1. A degradable cellulose acetate fiber, characterized by: The degradable cellulose acetate fiber is composed of a polymer, which includes cellulose acetate and an organic alkaline substance. The organic alkaline substance is uniformly distributed in the cellulose acetate.

2. The degradable cellulose acetate fiber according to claim 1, characterized in that: The cross-section of the degradable cellulose acetate fiber includes Y-shape, O-shape, R-shape, and X-shape; optionally, the single denier range of the degradable cellulose acetate fiber is 0.2-30.0D; optionally, the specific surface area range of the degradable cellulose acetate fiber is 0.01-10.0m 2 / g; optionally, the diameter of the circumscribed concentric circle of the degradable cellulose acetate fiber is in the range of 1.0 μm-200 μm; optionally, the degree of substitution of the cellulose acetate is in the range of 2.2-3.

0.

3. The degradable cellulose acetate fiber according to claim 2, characterized in that: The single denier of the degradable cellulose acetate fiber is preferably 2.0-15.0D; optionally, the diameter of the circumscribed concentric circle of the degradable cellulose acetate fiber is 25.0-80.0 μm; optionally, the specific surface area of the degradable cellulose acetate fiber is 0.8-2.4 m 2 / g.

4. The degradable cellulose acetate fiber according to claim 1, characterized in that: The degradable means that the alkaline substance can reduce the degree of substitution of the cellulose acetate fiber to below 2.2 after treatment in an aqueous solution, preferably to below 2.1, and more preferably to below 2.

0.

5. The degradable cellulose acetate fiber according to claim 1, characterized in that: The mass ratio of the organic alkaline substance in the cellulose acetate or degradable cellulose acetate fiber is 0.2-14.0%, preferably 1.0-7.0%.

6. The degradable cellulose acetate fiber according to claim 1, characterized in that: The pH value of the organic alkaline substance is in the range of 8.5-14.0, preferably in the range of 9.0-11.

0.

7. The degradable cellulose acetate fiber according to claim 1, characterized in that: The organic alkaline substance includes but is not limited to nitrogen-containing alkaline substances, including any one or more of acidic amino acids, basic amino acids, polypeptides with a degree of polymerization less than 100, 1-acetylguanidine, guanidine, quinine, 1-tert-butylcarbonylguanidine, tert-butylguanidine, polyamides with a degree of polymerization less than 100, polyhydrazide-PEG-hydrazide with a degree of polymerization less than 200, naphthalene, 1,8-bisdimethylaminonaphthalene, Schiff base, pyridine, pyrrole, imidazole, pyrazine, pyrimidine, pyridazine, and indole, preferably basic amino acids and / or 1-acetylguanidine, more preferably arginine and / or lysine.

8. The degradable cellulose acetate fiber according to claim 1, characterized in that: The organic alkaline substance is a basic amino acid, including but not limited to arginine. The mass ratio of the arginine in the cellulose polymer is 0.2-14.0%, preferably 1.0-7.0%.

9. The method for preparing the degradable cellulose acetate fiber according to claim 1, characterized in that: The method comprises the following steps: (1) dissolving cellulose acetate in solvent one to form a first homogeneous system; (2) dissolving an organic alkaline substance in solvent two first, and adding solvent one to the organic alkaline substance solution to form a second homogeneous system; (3) adding the second homogeneous system to the first homogeneous system to form a uniform degradable polymer composition, and mixing and uniformly distributing the composition to form a third uniform dispersion system; and (4) spinning the slurry of the third uniform dispersion system through a spinneret and subsequently drying the slurry to obtain the degradable cellulose acetate fiber.

10. The method for preparing degradable cellulose acetate fiber according to claim 9, characterized in that: The solvent one in step (1) includes any one or more of acetone, methyl butyl ketone, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, ethyl acetate, ethyl lactate, ethyl acetate, ethanol, 1-methyl-2-pyridine, DMF, DMSO, and chloroform, preferably any one or more of ethyl acetate, ethanol, acetone, methyl butyl ketone, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; The solvent 2 in step (2) includes any one or more of water, methanol, ethanol, propanol, butanol, isopropanol, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol ethyl ether, ethylene glycol, propylene glycol, butanediol, triethylene glycol, 1,2,6-hexanetriol, hexanediol, and diethylene glycol, preferably any one or more of water, methanol, ethanol, propanol, butanol, isopropanol, and tetrahydrofuran.

11. The method for preparing degradable cellulose acetate fiber according to claim 9, wherein: The weight ratio of the organic alkaline substance to the cellulose acetate is 0.5-10.0%; the weight ratio of the organic alkaline substance to the acetone aqueous solution is 5.0-40.0%.

12. The method for preparing degradable cellulose acetate fiber according to claim 9, wherein: In step (1), the solvent 1 is acetone, and the mass ratio of cellulose acetate to solvent 1 is W cellulose acetate:W solvent 1 = 1:1.5-3.5; The second solvent in step (2) is water, and the mass ratio of the organic alkaline substance to water is W organic base:W water = 1:2-70; In step (3), solvent 1 is added to the aqueous solution obtained in step (2) at a mass ratio of W organic base: W solvent 1 = 1:1-35 to form a second homogeneous system; the mass ratio of the first homogeneous system to the second homogeneous system is W1 phase: W2 phase = 3.57-18.7:

1.

13. The method for preparing degradable cellulose acetate fiber according to claim 9, wherein: In step (1), cellulose acetate is dissolved in solvent 1 at 0-100° C., preferably 10-70° C., to form a first homogeneous system; In step (2), the organic alkaline substance is first dissolved in solvent 2 at 0-100° C., preferably 10-70° C.; solvent 1 is added to the aqueous solution obtained in step (2) at a temperature of 10-70° C., preferably 15-50° C., to form a second homogeneous system; preferably, the solvent in step (1) is dripped into the aqueous solution obtained in step (2) at a rate of 1-10 mL / min to form a second homogeneous system; preferably, the solvent 1 in the second homogeneous system is acetone, and the mass ratio of acetone to water is W acetone:W water = 1:1.0-5.0; In step (3), the second homogeneous system is added to the first homogeneous system at 0-100° C., preferably 10-70° C. to form a uniform degradable polymer composition and mixed and evenly distributed to form a third uniformly dispersed system.

14. The method for preparing degradable cellulose acetate fiber according to claim 9, wherein: In step (4), the composition slurry is spun through a spinneret and hot air is used to volatilize and separate the solvent to prepare the degradable cellulose acetate fiber; optionally, the diameter of the circumscribed concentric circle of the degradable cellulose acetate fiber ranges from 1.0 μm to 200 μm; optionally, the temperature of the hot air is 50-300°C, preferably, the temperature of the hot air is 50-100°C.

15. The method for preparing degradable cellulose acetate fiber according to claim 9, characterized in that: The uniform distribution in step (4) means that the transmittance of the polymer slurry is 65.0%-92.0%, preferably 80.0%-92.0%.

16. The method for preparing degradable cellulose acetate fiber according to claim 9, characterized in that: The uniform distribution in step (4) means that the haze of the polymer slurry is in the range of 2.0% to 20.0%, preferably 3.0% to 13.0%.

17. The method for preparing degradable cellulose acetate fiber according to claim 9, characterized in that: The temperature for dissolving cellulose acetate in solvent one is preferably 10-70°C; the temperature for dissolving the organic alkaline substance in solvent two is preferably 10-70°C; preferably, the solvent one is acetone; the solvent two is water; the organic alkaline substance is arginine; preferably, the temperature for adding acetone to the arginine aqueous solution is preferably 15-50°C; Optionally, the speed of adding acetone to the arginine aqueous solution is 1-10 mL / min, preferably 3-8 mL / min; optionally, the mass ratio of acetone to water is W acetone:W water = 1:0.1-5, preferably, the mass ratio of acetone to water is W acetone:W water = 1:2.

7.

18. A degradable cellulose acetate tow, characterized by: Made of the degradable cellulose acetate fiber according to any one of claims 1 to 8, the diameter of the circumscribed concentric circle of the degradable cellulose filament bundle is in the range of 50μm-500μm, the single denier range is 0.2-30.0D, and the total denier range is 10000-60000D.

19. The method for preparing the degradable cellulose acetate polymer tow according to claim 18, characterized in that: The weight ratio of the organic alkaline substance to the acetate fiber is 0.5-7.0%; the weight ratio of the organic alkaline substance to the acetone aqueous solution is 5.0-40.0%; and the mass ratio of acetone to water is W acetone:W water = 1:2.

7.

20. The method for preparing the degradable cellulose polymer tow according to claim 18, characterized in that: The degradable cellulose acetate fiber according to any one of claims 1 to 8 is prepared by curling, drying, spinning and packaging.

21. Use of the degradable cellulose acetate fiber according to any one of claims 1 to 8 and the degradable cellulose tow according to claim 18 in traditional cigarettes and heat-not-burn cigarette filters.

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