Method for improving the antioxidant properties of hydroxyethylcellulose
By treating hydroxyethyl cellulose with surfactants and employing dispersion processes, the problem of low antioxidant properties of hydroxyethyl cellulose was solved, resulting in a significant improvement in its antioxidant performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LUZHOU NORTH CELLULOSE CO LTD
- Filing Date
- 2023-12-25
- Publication Date
- 2026-06-26
Smart Images
Figure CN117510997B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer materials technology, specifically relating to a method for improving the antioxidant properties of hydroxyethyl cellulose. Background Technology
[0002] Currently, hydroxyethyl cellulose produced in existing large-scale industrial production has relatively low antioxidant properties, making it susceptible to oxidation and affecting its performance during application. The antioxidant properties of hydroxyethyl cellulose, both domestically and internationally, are generally between 30% and 50%, or even lower.
[0003] Therefore, there is an urgent need to develop a method to improve the antioxidant properties of hydroxyethyl cellulose. Summary of the Invention
[0004] To address the technical problems of low antioxidant properties of hydroxyethyl cellulose in existing technologies, which makes it susceptible to oxidation and affects its performance during application, resulting in significant viscosity reduction, this invention uses surfactants to treat hydroxyethyl cellulose, promoting a more uniform reaction and better antioxidant effect.
[0005] This invention provides a method for improving the antioxidant properties of hydroxyethyl cellulose, comprising the following steps:
[0006] A. Disperse the surfactant in diluent A to obtain a surfactant slurry;
[0007] B. Add the hydroxyethyl cellulose slurry and the surfactant slurry obtained in step A to a kneader, heat the mixture, adjust the pH to weakly acidic, and knead.
[0008] C. The kneaded slurry is then centrifuged, dried, pulverized, and sieved to obtain hydroxyethyl cellulose with antioxidant properties.
[0009] In the above method, in step A, the diluent A is at least one of tert-butanol, isopropanol, or acetone.
[0010] In the above method, in step A, the surfactant is a carboxylate anionic surfactant, a sulfonate anionic surfactant, a sulfate anionic surfactant, or a phosphate anionic surfactant.
[0011] Preferably, in the above method, the surfactant is citric acid, sodium dodecylbenzenesulfonate, sodium alkyl alcohol polyoxyethylene ether sulfate, potassium tripolyphosphate, or sodium tripolyphosphate.
[0012] In the above method, in step A, the mass ratio of the surfactant to diluent A is 0.8–1.2:0.8–1.2.
[0013] In the above method, in step B, the hydroxyethyl cellulose slurry is etherified hydroxyethyl cellulose slurry from the production line, or is obtained by wetting and dispersing hydroxyethyl cellulose powder with diluent B.
[0014] In the above method, the diluent B is at least one of tert-butanol, isopropanol, or acetone.
[0015] In the above method, in step B, the mass ratio of hydroxyethyl cellulose in the hydroxyethyl cellulose slurry to the surfactant in the surfactant slurry is 1:0.01 to 0.08.
[0016] In the above method, step B, the heating is to raise the temperature to 30-50°C.
[0017] In the above method, step B, the specific operation of adjusting the pH to weak acidity is as follows: using at least one of acetic acid, hydrochloric acid, or nitric acid to adjust the pH to 5-7.
[0018] In the above method, in step B, the kneading time is 50-70 minutes.
[0019] In the above method, in step C, the centrifugation rate is ≥3000 r / min.
[0020] In the above method, in step C, the centrifugation time is 5 to 20 minutes.
[0021] In the above method, in step C, the drying temperature is 50-65°C, and the solvent is dried to ≤5wt%.
[0022] In the above method, step C, the crushing and sieving process involves crushing the material and then passing it through a 20-mesh sieve to collect the material that passes through the sieve.
[0023] The present invention also provides a hydroxyethyl cellulose with antioxidant properties, which is prepared by the above method and has excellent antioxidant properties.
[0024] The beneficial effects of this invention are:
[0025] This invention uses surfactants to control reaction conditions and externally encapsulates hydroxyethyl cellulose powder to alleviate the dispersion process of the product, promote the uniform dispersion of hydroxyethyl products, and enable oxide molecules to attack the side chains and main chains in sequence, thereby improving viscosity reduction and significantly enhancing the antioxidant properties of hydroxyethyl cellulose. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the water swelling process of hydroxyethyl cellulose.
[0027] Figure 2This is a schematic diagram illustrating the process of oxide attacking water-soluble macromolecules of hydroxyethyl cellulose under ideal conditions.
[0028] Figure 3 This is a schematic diagram illustrating the process of oxides attacking water-soluble macromolecules of hydroxyethyl cellulose in a real-world context. Detailed Implementation
[0029] Specifically, a method for improving the antioxidant properties of hydroxyethyl cellulose includes the following steps:
[0030] A. Disperse the surfactant in diluent A to obtain a surfactant slurry;
[0031] B. Add the hydroxyethyl cellulose slurry and the surfactant slurry obtained in step A to a kneader, heat the mixture, adjust the pH to weakly acidic, and knead.
[0032] C. The kneaded slurry is then centrifuged, dried, pulverized, and sieved to obtain hydroxyethyl cellulose with antioxidant properties.
[0033] In this field, hydroxyethyl cellulose swells in water to form water-soluble macromolecules (generally linear polymers), and the ultimately completely dissolved aqueous solution of hydroxyethyl cellulose becomes a colloid with intertwined molecular chains, thus generating viscosity, such as... Figure 1 As shown. This invention discovers that, under ideal conditions, hydroxyethyl cellulose water molecules are uniformly dispersed in aqueous solution. When attacked by oxide molecules, the surrounding side chains break first, and finally the main chain. This results in a viscosity reduction phenomenon in the hydroxyethyl cellulose aqueous solution, as shown. Figure 2 However, during the product swelling process, uneven dispersion and varying molecular chain lengths are inevitable. This results in oxide molecules attacking both side chains and the main chain, leading to significant viscosity reduction of the product within the same reaction time. Figure 3 .
[0034] Therefore, the inventors speculate that the uneven distribution of products under real-world conditions is the main source of low antioxidant properties. Thus, the inventors believe that improving the product's dispersion performance may be a breakthrough in solving the problem of low antioxidant properties. Based on this discovery, this invention addresses this issue by externally coating the etherified semi-finished hydroxyethyl cellulose slurry or finished hydroxyethyl cellulose powder on the production line. This alleviates the product dispersion process, and the coating material further promotes the uniform dispersion of the hydroxyethyl product, improving its antioxidant stability. Furthermore, the coating material allows oxide molecules to sequentially attack the molecular chains, thereby enhancing the antioxidant performance of the hydroxyethyl product.
[0035] In this invention, a surfactant is used to encapsulate hydroxyethyl cellulose. The surfactant is typically in paste or oil form. Therefore, in step A, diluent A is used to prepare it into a slurry form so that it can be uniformly kneaded with the hydroxyethyl cellulose. The diluent A is at least one of tert-butanol, isopropanol, or acetone.
[0036] In step A of this invention, the surfactant is a carboxylate anionic surfactant, a sulfonate anionic surfactant, a sulfate anionic surfactant, or a phosphate anionic surfactant; preferably, citric acid, sodium dodecylbenzenesulfonate, sodium alkyl alcohol polyoxyethylene ether sulfate, potassium tripolyphosphate (KTPP), or sodium tripolyphosphate (TSPP).
[0037] Through experiments, it was found that controlling the mass ratio of surfactant to diluent A in step A of this invention to be 0.8-1.2:0.8-1.2 yields a surfactant slurry with a suitable concentration, which is more conducive to kneading.
[0038] In step B of this invention, the hydroxyethyl cellulose slurry is either the etherified hydroxyethyl cellulose slurry produced on the production line, or obtained by wetting and dispersing hydroxyethyl cellulose powder with diluent B. The etherified hydroxyethyl cellulose slurry produced on the production line essentially only lacks post-processing steps such as drying and pulverizing to obtain the finished hydroxyethyl cellulose powder. Therefore, it can be considered that the semi-finished hydroxyethyl cellulose slurry produced on the production line and the slurry obtained by wetting and dispersing the finished hydroxyethyl cellulose powder with diluent B are essentially the same substance. The diluent B is at least one of tert-butanol, isopropanol, or acetone, and the diluent B used for wetting and dispersing the powder is similar to the solvent system in the etherified hydroxyethyl cellulose slurry.
[0039] In this invention, when using finished hydroxyethyl cellulose powder, direct use results in significant dust generation and hinders the uniform kneading and dispersion of the diluent. Therefore, this invention first uses an appropriate amount of diluent B to transform the powder into a cotton-like consistency, facilitating kneading and preventing dust. The amount of diluent B is not limited (generally, the mass ratio of hydroxyethyl cellulose powder to diluent B is 1:0.5-2).
[0040] Through experiments, it was found that in step B of the present invention, the mass ratio of hydroxyethyl cellulose in the hydroxyethyl cellulose slurry to the surfactant in the surfactant slurry is controlled to be 1:0.01 to 0.08. This amount can effectively coat the hydroxyethyl cellulose, promote the uniform dispersion of the product, and significantly improve its antioxidant stability.
[0041] In step B of this invention, the temperature increase is to raise the temperature to 30-50°C.
[0042] In the above method, step B, the specific operation of adjusting the pH to weak acidity is as follows: using at least one of acetic acid, hydrochloric acid, or nitric acid to adjust the pH to 5-7.
[0043] In the above method, in step B, the kneading time is 50-70 minutes.
[0044] In step C of this invention, the centrifugation rate is controlled to be ≥3000 r / min, and solvents such as diluent A (or diluent B) have been removed to facilitate drying; the centrifugation time is 5 to 20 min.
[0045] In step C of this invention, the drying temperature is controlled at 50-65°C, and the solvent is dried until it is ≤5wt% (the drying time is determined according to the remaining moisture content).
[0046] In step C of this invention, the crushing and sieving process involves passing the crushed material through a 20-mesh sieve to collect the undersize material. If the product particles are too large, they can easily cause the product to dissolve and become encapsulated. However, if the particles are too small, the dust will be heavy and the viscosity will easily decrease. Therefore, the crushing and sieving process is controlled, and the material is generally crushed to 20-40 mesh.
[0047] The present invention also provides a hydroxyethyl cellulose with antioxidant properties, which is prepared by the above method and has excellent antioxidant properties.
[0048] In this invention, diluent A, diluent B, and the solvent in the etherified semi-finished hydroxyethyl cellulose slurry on the production line are all commonly used solvents in hydroxyethyl cellulose production lines; however, the three do not necessarily have to be exactly the same.
[0049] The present invention will be further described in detail below through embodiments, but the scope of protection of the present invention is not limited to the embodiments described herein.
[0050] Example 1
[0051] (1) The surfactant (sodium dodecylbenzenesulfonate) and diluent A (a mixed solution of isopropanol and tert-butanol in a mass ratio of 1:1) are mixed and dispersed in a mass ratio of 1:1 to obtain a surfactant slurry;
[0052] (2) The hydroxyethyl cellulose powder (original sample 2) was wetted and dispersed with diluent B (a mixed solvent of isopropanol, tert-butanol and acetone in a mass ratio of 1:1:1) to obtain hydroxyethyl cellulose slurry; 1 kg of hydroxyethyl cellulose powder was used to take hydroxyethyl cellulose slurry, 0.03 kg of surfactant was used to take surfactant slurry, and the mixture was added to a kneader, heated to 50°C, and the pH was adjusted to 5.0 with acetic acid. The mixture was kneaded for 1 hour.
[0053] (3) Centrifuge the kneaded slurry to remove the diluent. The centrifugation speed is ≥3000r / min and the centrifugation time is 15min. Then dry it at 50℃ until the moisture content is ≤5% and then pulverize it to 20-40M to prepare hydroxyethyl cellulose with antioxidant properties.
[0054] Example 2
[0055] (1) The surfactant (sodium dodecylbenzenesulfonate) and diluent A (a mixed solution of isopropanol and acetone, with a mass ratio of 1:1) are mixed and dispersed at a mass ratio of 1:1 to obtain a surfactant slurry;
[0056] (2) Wet and disperse hydroxyethyl cellulose powder with diluent B (mixed solvent of isopropanol, tert-butanol and acetone, mass ratio 1:1:1) to obtain hydroxyethyl cellulose slurry; take hydroxyethyl cellulose slurry at 1 kg of hydroxyethyl cellulose powder and surfactant slurry at 0.07 kg of surfactant, add them to a kneader, heat to 45℃, adjust pH to 6.5 with acetic acid, and knead for 1 h;
[0057] (3) Centrifuge the kneaded slurry to remove the diluent. The centrifugation speed is ≥3000r / min and the centrifugation time is 20min. Then dry it at 50℃ until the moisture content is ≤5% and then pulverize it to 20-40M to prepare hydroxyethyl cellulose with antioxidant properties.
[0058] Example 3
[0059] (1) Mix and disperse the surfactant (citric acid) and diluent A (isopropanol) at a mass ratio of 1:1.2 to obtain a surfactant slurry;
[0060] (2) The hydroxyethyl cellulose powder (original sample 1) was wetted and dispersed with diluent B (a mixed solvent of isopropanol, tert-butanol and acetone in a mass ratio of 1:1:1) to obtain hydroxyethyl cellulose slurry; 1 kg of hydroxyethyl cellulose powder was used to take hydroxyethyl cellulose slurry, 0.05 kg of surfactant was used to take surfactant slurry, and the mixture was added to a kneader, heated to 45°C, and the pH was adjusted to 7.0 with acetic acid. The mixture was kneaded for 1 hour.
[0061] (3) Centrifuge the kneaded slurry to remove the diluent. The centrifugation speed is ≥3000r / min and the centrifugation time is 20min. Then dry it at 50℃ until the moisture content is ≤5% and then pulverize it to 20-40M to prepare hydroxyethyl cellulose with antioxidant properties.
[0062] Example 4
[0063] (1) The surfactant (sodium tripolyphosphate) and diluent A (a mixed solution of isopropanol and acetone, with a mass ratio of 1:1) are mixed and dispersed at a mass ratio of 1:0.8 to obtain a surfactant slurry;
[0064] (2) Wet and disperse hydroxyethyl cellulose powder with diluent B (mixed solvent of isopropanol, tert-butanol and acetone, mass ratio 1:1:1) to obtain hydroxyethyl cellulose slurry; take hydroxyethyl cellulose slurry at 1 kg of hydroxyethyl cellulose powder and surfactant slurry at 0.07 kg of surfactant, add them to a kneader, heat to 45℃, adjust pH to 5.5 with acetic acid, and knead for 1 h;
[0065] (3) Centrifuge the kneaded slurry to remove the diluent. The centrifugation speed is ≥3000r / min and the centrifugation time is 20min. Then dry it at 50℃ until the moisture content is ≤5% and then pulverize it to 20-40M to prepare hydroxyethyl cellulose with antioxidant properties.
[0066] Example 5
[0067] (1) The surfactant (sodium tripolyphosphate) and diluent A (a mixed solution of isopropanol and acetone, with a mass ratio of 1:1) are mixed and dispersed at a mass ratio of 1:1.2 to obtain a surfactant slurry;
[0068] (2) Take 1 kg of dry hydroxyethyl cellulose, take the semi-finished hydroxyethyl cellulose slurry after etherification on the production line, take 0.08 kg of surfactant, take the surfactant slurry, add it to the kneader, heat it to 40℃, adjust the pH to 6.0 with acetic acid, and knead for 70 min.
[0069] (3) Centrifuge the kneaded slurry to remove the diluent. The centrifugation speed is ≥3000r / min and the centrifugation time is 25min. Then dry it at 50℃ until the moisture content is ≤5% and then pulverize it to 20-40M to prepare hydroxyethyl cellulose with antioxidant properties.
[0070] Table 1. Physicochemical analysis results of the samples
[0071]
[0072]
[0073] Note: Original sample 1 is the initial hydroxyethyl cellulose powder in Example 1; original sample 2 is the initial hydroxyethyl cellulose powder in Example 2; antioxidant performance refers to the product's ability to retain viscosity after 24 hours of contact with the oxidant, and its calculation formula is: viscosity after 24 hours / initial viscosity * 100%.
Claims
1. A method for improving the antioxidant properties of hydroxyethyl cellulose, characterized in that: Includes the following steps: A. Disperse the surfactant in diluent A to obtain a surfactant slurry; B. Add the hydroxyethyl cellulose slurry and the surfactant slurry obtained in step A to a kneader, heat the mixture, adjust the pH to weakly acidic, and knead. C. The kneaded slurry is then centrifuged, dried, pulverized, and sieved to obtain hydroxyethyl cellulose with antioxidant properties. In step A, the diluent A is at least one of tert-butanol, isopropanol, or acetone; In step A, the surfactant is citric acid, sodium dodecylbenzene sulfonate, sodium alkyl alcohol polyoxyethylene ether sulfate, potassium tripolyphosphate, or sodium tripolyphosphate. In step B, the hydroxyethyl cellulose slurry is the etherified hydroxyethyl cellulose slurry from the production line, or it is obtained by wetting and dispersing hydroxyethyl cellulose product powder with diluent B. In step B, the mass ratio of hydroxyethyl cellulose in the hydroxyethyl cellulose slurry to the surfactant in the surfactant slurry is 1:0.01 to 0.08; In step B, the temperature increase is to raise the temperature to 30-50°C; In step B, the specific operation of adjusting the pH to a slightly acidic state is as follows: using at least one of acetic acid, hydrochloric acid, or nitric acid to adjust the pH to 5-7.
2. The method for improving the antioxidant properties of hydroxyethyl cellulose according to claim 1, characterized in that: In step A, the mass ratio of the surfactant to diluent A is 0.8~1.2:0.8~1.
2.
3. The method for improving the antioxidant properties of hydroxyethyl cellulose according to claim 1, characterized in that: The diluent B is at least one of tert-butanol, isopropanol, or acetone.
4. The method for improving the antioxidant properties of hydroxyethyl cellulose according to any one of claims 1 to 3, characterized in that: In step B, the kneading time is 50-70 minutes.
5. The method for improving the antioxidant properties of hydroxyethyl cellulose according to any one of claims 1 to 3, characterized in that: In step C, at least one of the following must be satisfied: The centrifugation rate is ≥3000 r / min; The centrifugation time is 5-20 minutes; The drying temperature is 50~65℃, and the solvent is dried to ≤5wt%; The crushing and sieving process involves crushing the material and then passing it through a 20-mesh sieve to collect the material that passes through the sieve.