CN115873145A - Preparation method of carboxymethyl chitosan - Google Patents
Preparation method of carboxymethyl chitosan Download PDFInfo
- Publication number
- CN115873145A CN115873145A CN202310212835.2A CN202310212835A CN115873145A CN 115873145 A CN115873145 A CN 115873145A CN 202310212835 A CN202310212835 A CN 202310212835A CN 115873145 A CN115873145 A CN 115873145A
- Authority
- CN
- China
- Prior art keywords
- primary
- alkalization
- chitosan
- carboxylation
- carboxymethyl chitosan
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Polysaccharides And Polysaccharide Derivatives (AREA)
Abstract
The invention provides a preparation method of carboxymethyl chitosan, belonging to the field of carboxymethyl chitosan. The preparation method of the carboxymethyl chitosan comprises the following steps: primary alkalization, secondary alkalization, primary carboxylation, secondary carboxylation and post-treatment. The preparation method of the carboxymethyl chitosan can obtain an ideal substitution effect aiming at high molecular weight chitosan, can realize effective substitution on primary amino group at 2-position of the chitosan, and effectively improves the substitution degree; simultaneously, the adverse effect caused by microwave radiation in the carboxylation process in the prior art is overcome, the problem that the microwave radiation may cause chain scission and degradation of high molecular weight chitosan is avoided, and the prepared carboxymethyl chitosan has the viscosity-average molecular weight of (23.8-26.9) x 10 4 The total degree of substitution is 1.81-1.87, wherein the degree of substitution at the O position is 1.40-1.44 and the degree of substitution at the N position is 0.41-0.43.
Description
Technical Field
The invention relates to the field of preparation of carboxymethyl chitosan, in particular to a preparation method of carboxymethyl chitosan.
Background
Chitin is a polysaccharide substance extracted from the shell of marine crustaceans, and has the chemical formula (C) 8 H 13 O 5 N) n . Chitin is oneA non-toxic, odorless, white or off-white translucent solid is soluble in concentrated hydrochloric acid, phosphoric acid, sulfuric acid and acetic acid, insoluble in alkali and other organic solvents, and insoluble in water. Chitin is treated by concentrated alkali to remove more than 55% of N-acetyl, and chitosan (chitosan) is obtained, which is insoluble in water and soluble in partial dilute acid. Chitin and chitosan have many unique properties such as biodegradability, cell affinity, biological effect and the like, particularly chitosan containing free amino is the only alkaline polysaccharide in natural polysaccharide, and can be widely applied to the fields of food, environmental protection, beauty and health care, antibacterial agents, medical fibers, medical dressings, artificial tissue materials, drug sustained release materials, gene transduction carriers, biomedical fields, medical absorbable materials and the like.
Carboxymethyl chitosan is a chitosan derivative modified by carboxymethylation, has good water solubility, permeability, moisture retention and antibacterial property, and can promote epithelial cell growth, delay cell aging and promote skin ulcer wound healing. It is currently used in medicine, beauty treatment and fruit and vegetable fresh-keeping. Meanwhile, the carboxymethyl chitosan can also be used as a flocculating agent, a metal ion chelating agent and the like in water treatment. In recent years, carboxymethyl chitosan has become one of the most studied and applied chitosan derivatives.
In the prior art, the preparation method of carboxymethyl chitosan mainly comprises the step of carrying out carboxymethyl substitution reaction on chitosan and chloroacetic acid and the like in an alkaline environment. The preparation process of carboxymethyl chitosan is essentially that the 2-primary amino group and the 3-and 6-hydroxyl groups of the chitosan are completely or partially subjected to carboxymethyl substitution reaction. The substitution sequence is 6-hydroxyl, 3-hydroxyl and 2-primary amino, and the substitution degree is obviously increased along with the reduction of the molecular weight of the chitosan. The reason is that with the increase of molecular weight, chitosan as a long-chain polymer compound has steric hindrance and strong hydrogen bonding effect in molecules and between molecules, the structure of the chitosan is changed from a disordered structure to an ordered structure, and the structure seriously hinders NaOH and CICH 2 The permeation of small molecules such as COOH prevents the carboxymethyl substitution reaction, and finally, the desired substitution effect of high molecular weight chitosan, especially on the primary amino group at the 2-position, cannot be obtainedThe effective substitution can not be effectively improved, and the further expansion of the application of the carboxymethyl chitosan in various fields is limited.
Furthermore, microwave radiation is usually adopted in the prior art to improve the substitution effect of carboxymethyl. However, in the actual operation of preparing carboxymethyl chitosan by using high molecular weight chitosan, microwave radiation may cause the phenomena of chain scission, degradation and the like of the high molecular weight chitosan, which not only causes the molecular weight of part of chitosan to be reduced, but also causes the carboxymethyl chitosan with high and low molecular weights to be blended; the quality of the prepared carboxymethyl chitosan product is unstable, and the stable and uniform moisturizing performance cannot be realized in the later application process.
Disclosure of Invention
Aiming at high molecular weight chitosan, the ideal substitution effect can be obtained, effective substitution can be realized on the 2-primary amino group of the chitosan, and the substitution degree is effectively improved; meanwhile, adverse effects caused by microwave radiation in the carboxylation process in the prior art are overcome, the problems of chain scission and degradation of high molecular weight chitosan possibly caused by microwave radiation are avoided, the prepared carboxymethyl chitosan product is stable in quality, and stable and uniform moisturizing performance is realized in the later application process.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
a preparation method of carboxymethyl chitosan, which comprises the following steps: primary alkalization, secondary alkalization, primary carboxylation, secondary carboxylation and post-treatment.
The primary alkalization method comprises the steps of putting sodium hydroxide into ethanol water solution with the volume concentration of 50-55% under the stirring condition, and adjusting the concentration of the sodium hydroxide to 15-20wt% to prepare alkalized liquid; under the condition of stirring, adding chitosan into the alkalization liquid, and adjusting the concentration of chitosan in the alkalization liquid to be 5-7wt% to prepare chitosan dispersion liquid; carrying out first ultrasonic treatment on the chitosan dispersion liquid for 10-30min; then cooling to minus 30 ℃ to minus 35 ℃ at a cooling rate of 0.2-0.5 ℃/min, and carrying out heat preservation treatment for 3-5h to obtain a primary alkalinized substance;
in the primary alkalization, the viscosity average molecular weight M eta of the chitosan is (35-40) multiplied by 10 4 The degree of deacetylation is 75-85%, and the particle size is 0.1-0.3mm;
in the primary alkalization, the frequency of the first ultrasonic treatment is 30-33kHz, and the ultrasonic power is 400-500W.
The secondary alkalization method comprises the steps of naturally rewarming the primary alkalization to 3-8 ℃, adding a saturated sodium hydroxide aqueous solution under stirring, adjusting the concentration of sodium hydroxide to 35-40wt%, and performing secondary ultrasonic treatment for 10-20min to obtain a secondary alkalization;
in the secondary alkalization, the frequency of the second ultrasonic treatment is 33-35kHz, and the ultrasonic power is 400-500W.
The primary carboxylation method comprises the steps of adding a predetermined amount of a carboxylation agent and a catalyst into the secondary alkali compound, heating to 40-50 ℃, preserving heat, and carrying out primary carboxylation reaction for 1-2 hours to obtain the primary carboxylate. In the course of one carboxylation reaction, ultraviolet light with the wavelength of 385-395nm is adopted for radiation treatment.
In the primary carboxylation, the carboxylating agent is a mixture of chloroacetic acid and trichloroacetic acid, and the weight part ratio of the chloroacetic acid to the trichloroacetic acid is 1:3-4;
in the primary carboxylation, the addition amount of the carboxylating agent is 3-6 times of the weight of the chitosan in the primary alkalization.
In the primary carboxylation, a catalyst is a mixture of lauryl dimethyl amine oxide and dodecyl trimethyl ammonium chloride, and the ratio of the weight parts of the lauryl dimethyl amine oxide to the weight parts of the dodecyl trimethyl ammonium chloride is 2-3:1;
in the primary carboxylation, the addition amount of the catalyst is 0.2-0.5% of the weight of the chitosan in the primary alkalization.
The secondary carboxylation method comprises the steps of continuously heating the primary carboxylate to 50-60 ℃, then preserving the temperature, and carrying out secondary carboxylation reaction for 30-60min to obtain the secondary carboxylate. In the secondary carboxylation process, ultraviolet light with the wavelength of 390-400nm is adopted for radiation treatment.
Naturally cooling the secondary carboxylate to normal temperature, adding the secondary carboxylate into 3-5 times volume of absolute ethyl alcohol, adjusting the pH value to 6.8-7.2 by adopting 30-40wt% of acetic acid, and standing until no solid is separated out; and then centrifugally separating out solids by adopting a centrifugal rotating speed of 12000-15000rpm, washing the solids by adopting sufficient ethanol solution with the concentration of 70-80% until no chloride ions exist, then leaching the solids by adopting 2-3 times of volume of absolute ethanol once, placing the solids in a vacuum environment, and drying the solids at 60-70 ℃ until the weight of the solids is unchanged to prepare the carboxymethyl chitosan.
Compared with the prior art, the invention has the beneficial effects that:
(1) According to the preparation method of the carboxymethyl chitosan, the chitosan is alkalized and swelled in a secondary alkalization mode in a specific ethanol solution; in the secondary alkalization process, ultrasonic treatment with specific technological parameters (such as ultrasonic frequency and the like) is set, so that adverse effects of ultrasonic on high molecular weight chitosan are avoided while alkalization and swelling of chitosan are promoted; realizes good alkalization and swelling effects and reduces OH - The difficulty of permeating into the chitosan is easier to form an alkalization active center, the reaction effect of subsequent carboxylation is promoted, the substitution degree is effectively improved, and particularly the substitution degree of carboxymethyl on 2-primary amino group is improved.
(2) According to the preparation method of carboxymethyl chitosan, a specific carboxylation agent, a catalyst and a secondary alkalinization compound are used for secondary carboxylation, ultraviolet light with specific wavelength is set for radiation treatment in the secondary carboxylation process, so that adverse effects of the ultraviolet light on high molecular weight chitosan are avoided while carboxylation reaction of the alkalized chitosan is promoted, the possible problems of chain scission and degradation are avoided, the substitution degree is further improved, and particularly the substitution degree of carboxymethyl on 2-primary amino group is improved. The obtained carboxymethyl chitosan has viscosity average molecular weight (M eta) of (23.8-26.9) × 10 4 The total degree of substitution is 1.81-1.87, wherein the degree of substitution at the O position is 1.40-1.44 and the degree of substitution at the N position is 0.41-0.43.
(3) The carboxymethyl chitosan product prepared by the preparation method of the carboxymethyl chitosan has stable quality, and through detection, the 24-hour moisture absorption rate is 36.8-37.3% and the 48-hour moisture absorption rate is 40.7-41.6% under the condition that RH = 43%; under the condition that RH =81%, the moisture absorption rate of 24h is 50.5-51.4%, and the moisture absorption rate of 48h is 55.8-57.5%; under the condition of RH =43%, the 24h moisture retention rate is 356.1-357.2%, and the 48h moisture retention rate is 411.9-412.8%; under the condition of RH =81%, the moisture retention rate of 24h is 434.0-435.5%, and the moisture retention rate of 48h is 471.1-472.3%.
(4) The preparation method of carboxymethyl chitosan of the invention has simple process method and easy control of the preparation process, and can be suitable for large-scale industrial production.
Detailed Description
In order to more clearly understand the technical features, objects, and effects of the present invention, specific embodiments of the present invention will now be described.
Example 1
A preparation method of carboxymethyl chitosan, which comprises the following steps: primary alkalization, secondary alkalization, primary carboxylation, secondary carboxylation and post-treatment. The method comprises the following specific steps:
1. primary alkalization
Under the condition of stirring, putting sodium hydroxide into an ethanol water solution with the volume concentration of 50%, and adjusting the concentration of the sodium hydroxide to be 15wt% to prepare an alkalized solution; under the condition of stirring, adding chitosan into the alkalization liquid, and adjusting the concentration of chitosan in the alkalization liquid to be 5wt% to prepare chitosan dispersion liquid; carrying out first ultrasonic treatment on the chitosan dispersion liquid for 10min; then cooling to minus 30 ℃ at a cooling rate of 0.2 ℃/min, and carrying out heat preservation treatment for 3 hours to obtain the primary alkalinized substance.
In the primary alkalization, the viscosity average molecular weight (M eta) of chitosan is 35 × 10 4 The degree of deacetylation was 85% and the particle size was 0.1mm.
In the primary alkalization, the frequency of the first ultrasonic treatment was 30kHz and the ultrasonic power was 400W.
2. Second alkalization
Naturally rewarming the primary alkalinized substance to 3 ℃, adding saturated sodium hydroxide aqueous solution under stirring, adjusting the concentration of sodium hydroxide to 35wt%, and performing secondary ultrasonic treatment for 10min to obtain a secondary alkalinized substance.
In the secondary alkalization, the frequency of the second ultrasonic treatment is 33kHz, and the ultrasonic power is 400W.
3. First carboxylation
Adding a predetermined amount of a carboxylating agent and a catalyst into the secondary alkali, heating to 40 ℃, preserving heat, and carrying out primary carboxylation reaction for 1h to obtain a primary carboxylate. During the primary carboxylation reaction, ultraviolet light with the wavelength of 385nm is used for radiation treatment.
Wherein the carboxylating agent is a mixture of chloroacetic acid and trichloroacetic acid, and the weight part ratio of the chloroacetic acid to the trichloroacetic acid is 1:3.
The addition amount of the carboxylating agent is 3 times of the weight of the chitosan.
The catalyst is a mixture of lauryl dimethyl amine oxide and dodecyl trimethyl ammonium chloride, and the weight part ratio of the lauryl dimethyl amine oxide to the dodecyl trimethyl ammonium chloride is 2:1.
The addition amount of the catalyst is 0.2 percent of the weight of the chitosan.
4. Second carboxylation
And continuously heating the primary carboxylate to 50 ℃, preserving the temperature, and carrying out secondary carboxylation reaction for 30min to obtain a secondary carboxylate. In the secondary carboxylation process, ultraviolet light with the wavelength of 390nm is adopted for radiation treatment.
5. Post-treatment
Naturally cooling the secondary carboxylate to normal temperature, adding into 3 times volume of anhydrous ethanol, adjusting pH to 6.8 with 30wt% acetic acid, and standing until no solid is separated out; and then centrifugally separating out solids by adopting a centrifugal rotating speed of 12000rpm, washing the solids by adopting sufficient ethanol solution with the concentration of 70% until no chloride ions exist, then rinsing the solids by adopting absolute ethanol with the volume of 2 times, placing the solids in a vacuum environment, and drying the solids at 60 ℃ until the weight of the solids is unchanged to prepare the carboxymethyl chitosan.
Example 2
A preparation method of carboxymethyl chitosan, which comprises the following steps: primary alkalization, secondary alkalization, primary carboxylation, secondary carboxylation and post-treatment. The method comprises the following specific steps:
1. primary alkalization
Under the condition of stirring, adding sodium hydroxide into an ethanol aqueous solution with the volume concentration of 52 percent, and adjusting the concentration of the sodium hydroxide to 18 weight percent to prepare an alkalized solution; under the condition of stirring, adding chitosan into the alkalization liquid, and adjusting the concentration of chitosan in the alkalization liquid to be 6wt% to prepare chitosan dispersion liquid; carrying out first ultrasonic treatment on the chitosan dispersion liquid for 20min; then cooling to 32 ℃ below zero at a cooling rate of 0.3 ℃/min, and carrying out heat preservation treatment for 4h to obtain the primary alkalinized substance.
In the primary alkalization, the viscosity-average molecular weight (M eta) of the chitosan is 38 multiplied by 10 4 The degree of deacetylation was 80% and the particle size was 0.2mm.
In the primary alkalization, the frequency of the first ultrasonic treatment was 31kHz and the ultrasonic power was 450W.
2. Second alkalization
Naturally rewarming the primary alkalinized substance to 5 ℃, adding saturated sodium hydroxide aqueous solution under stirring, adjusting the concentration of sodium hydroxide to 38wt%, and performing secondary ultrasonic treatment for 15min to obtain a secondary alkalinized substance.
In the secondary alkalization, the frequency of the second ultrasonic treatment is 34kHz, and the ultrasonic power is 450W.
3. First carboxylation
Adding a predetermined amount of a carboxylating agent and a catalyst into the secondary alkali, heating to 45 ℃, preserving heat, and carrying out primary carboxylation reaction for 1.5h to obtain a primary carboxylate. During the primary carboxylation reaction, ultraviolet light with the wavelength of 390nm is adopted for radiation treatment.
Wherein the carboxylating agent is a mixture of chloroacetic acid and trichloroacetic acid, and the weight part ratio of the chloroacetic acid to the trichloroacetic acid is 1.
The addition amount of the carboxylating agent is 5 times of the weight of the chitosan.
The catalyst is a mixture of lauryl dimethyl amine oxide and dodecyl trimethyl ammonium chloride, and the weight part ratio of the lauryl dimethyl amine oxide to the dodecyl trimethyl ammonium chloride is 2.5.
The addition amount of the catalyst is 0.3 percent of the weight of the chitosan.
4. Second carboxylation
And continuously heating the primary carboxylate to 55 ℃, preserving the temperature, and carrying out secondary carboxylation reaction for 40min to obtain a secondary carboxylate. In the secondary carboxylation process, ultraviolet light with the wavelength of 395nm is used for radiation treatment.
5. Post-treatment
Naturally cooling the secondary carboxylate to normal temperature, putting into anhydrous ethanol with the volume of 4 times, adjusting the pH value to 7.0 by adopting acetic acid with the concentration of 35wt%, and standing until no solid is separated out; and then centrifugally separating out solids at the centrifugal speed of 14000rpm, washing the solids by using sufficient ethanol solution with the concentration of 75% until no chloride ions exist, leaching the solids by using 2.5 times of volume of absolute ethanol once, placing the solids in a vacuum environment, and drying the solids at 65 ℃ until the weight of the solids is unchanged to obtain the carboxymethyl chitosan.
Example 3
A preparation method of carboxymethyl chitosan, which comprises the following steps: primary alkalization, secondary alkalization, primary carboxylation, secondary carboxylation and post-treatment. The method comprises the following specific steps:
1. primary alkalization
Under the condition of stirring, adding sodium hydroxide into an ethanol aqueous solution with the volume concentration of 55%, and adjusting the concentration of the sodium hydroxide to be 20wt% to prepare an alkalized solution; under the condition of stirring, adding chitosan into the alkalization liquid, and adjusting the concentration of chitosan in the alkalization liquid to be 7wt% to prepare chitosan dispersion liquid; carrying out first ultrasonic treatment on the chitosan dispersion liquid for 30min; then cooling to 35 ℃ below zero at a cooling rate of 0.5 ℃/min, and carrying out heat preservation treatment for 5h to obtain the primary alkalinized substance.
In primary alkalization, the viscosity-average molecular weight (M eta) of chitosan is 40 × 10 4 The degree of deacetylation was 75% and the particle size was 0.3mm.
In the primary alkalization, the frequency of the first ultrasonic treatment was 33kHz and the ultrasonic power was 500W.
2. Second alkalization
Naturally rewarming the primary alkalinized substance to 8 ℃, adding saturated sodium hydroxide aqueous solution under stirring, adjusting the concentration of sodium hydroxide to 40wt%, and performing secondary ultrasonic treatment for 20min to obtain a secondary alkalinized substance.
In the secondary alkalization, the frequency of the second ultrasonic treatment is 35kHz, and the ultrasonic power is 500W.
3. First carboxylation
Adding a predetermined amount of a carboxylating agent and a catalyst into the secondary alkali, heating to 50 ℃, preserving heat, and carrying out primary carboxylation reaction for 2 hours to obtain a primary carboxylate. During the primary carboxylation reaction, ultraviolet light with the wavelength of 395nm is adopted for radiation treatment.
Wherein the carboxylating agent is a mixture of chloroacetic acid and trichloroacetic acid, and the weight part ratio of the chloroacetic acid to the trichloroacetic acid is 1:4.
The addition amount of the carboxylating agent is 6 times of the weight of the chitosan.
The catalyst is a mixture of lauryl dimethyl amine oxide and dodecyl trimethyl ammonium chloride, and the weight part ratio of the lauryl dimethyl amine oxide to the dodecyl trimethyl ammonium chloride is 3:1.
The addition amount of the catalyst is 0.5 percent of the weight of the chitosan.
4. Second carboxylation
And continuously heating the primary carboxylate to 60 ℃, preserving the temperature, and performing secondary carboxylation reaction for 60min to obtain a secondary carboxylate. In the secondary carboxylation process, ultraviolet light with the wavelength of 400nm is adopted for radiation treatment.
5. Post-treatment
Naturally cooling the secondary carboxylate to normal temperature, adding the secondary carboxylate into 5 times volume of absolute ethyl alcohol, adjusting the pH value to 7.2 by adopting acetic acid with the concentration of 40wt%, and standing until no solid is separated out; and then centrifugally separating out solid matters at the centrifugal speed of 15000rpm, washing the solid matters by using sufficient ethanol solution with the concentration of 80% until no chloride ions exist, then leaching the solid matters by using anhydrous ethanol with the volume of 3 times, placing the solid matters in a vacuum environment, and drying the solid matters at 70 ℃ until the weight of the solid matters is unchanged to obtain the carboxymethyl chitosan.
Comparative example 1
The technical scheme of the embodiment 2 is adopted, and the difference is that: 1) In the primary alkalization and the secondary alkalization steps, the first ultrasonic treatment and the second ultrasonic treatment are omitted. 2) In the primary alkalization step, deionized water is adopted to replace 52% ethanol water solution.
Comparative example 2
The technical scheme of the embodiment 2 is adopted, and the difference is that: 1) In the step of primary carboxylation, microwave radiation is adopted for heating and heat preservation to assist the carboxylation reaction; wherein the frequency of the microwave radiation is 3000MHz, and the microwave power is 600W. 2) The second carboxylation step was omitted.
The viscosity average molecular weight, total substitution degree, substitution degree at the O site, and substitution degree at the N site of the carboxymethyl chitosan prepared in examples 1 to 3 and comparative examples 1 to 2 were measured, and the specific results are shown in table 1:
TABLE 1 summary of the results of the molecular weight and substitution of carboxymethyl chitosan
Further, the moisture absorption and retention properties of the carboxymethyl chitosans prepared in examples 1-3 and comparative examples 1-2 were measured. Specifically, the moisture absorption performance was measured under humidity conditions of 43% and 81% Relative Humidity (RH), respectively; the moisturizing performance was measured under Relative Humidity (RH) of 43% and 81% and dry conditions, respectively.
The method for detecting the hygroscopicity of the carboxymethyl chitosan comprises the following steps: respectively weighing W 0 The carboxymethyl chitosans prepared in examples 1 to 3 and comparative examples 1 to 2, in which the amount of each of the carboxymethyl chitosans was 0.5g, were placed in a desiccator for moisture absorption in which a saturated aqueous solution of ammonium sulfate was used to maintain a relative humidity RH =43% and a relative humidity RH =81%, and were weighed once at 24h and 48h to obtain W 1 Numerical values. And calculating the moisture absorption rate.
The calculation method of the moisture absorption rate comprises the following steps: moisture absorption rate (%) = [ (W) 1- -W 0 ）/W 0 ]×100%
The detection method of the moisture retention of the carboxymethyl chitosan comprises the following steps: the water content of the carboxymethyl chitosan prepared in examples 1-3 and comparative examples 1-2 was adjusted to H 0 =10wt%, and then placed in a relative humidity RH =43% and a relative humidity RH =81% and a silica gel dryer, respectively, and weighed once at 24H and 48H to obtain H 1 Numerical values. And the moisture residual rate was calculated.
The calculation method of the water residual rate comprises the following steps: water remaining ratio (%) = (H) 1 /H 0 ）×100%
The specific test results are shown in table 2:
TABLE 2 summary table of the results of testing moisture absorption and retention rates of carboxymethyl chitosan
All percentages used in the present invention are mass percentages unless otherwise indicated.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (5)
1. The preparation method of carboxymethyl chitosan is characterized by comprising the following steps: primary alkalization, secondary alkalization, primary carboxylation, secondary carboxylation and post-treatment;
the primary alkalization method comprises the steps of putting sodium hydroxide into ethanol water solution with the volume concentration of 50-55% under the stirring condition, and adjusting the concentration of the sodium hydroxide to 15-20wt% to prepare alkalized liquid; under the condition of stirring, adding chitosan into the alkalization liquid, and adjusting the concentration of chitosan in the alkalization liquid to be 5-7wt% to prepare chitosan dispersion liquid; performing first ultrasonic treatment on the chitosan dispersion liquid for 10-30min; then cooling to minus 30-minus 35 ℃, and carrying out heat preservation treatment for 3-5h to obtain a primary alkalinized substance;
in the primary alkalization, the frequency of the first ultrasonic treatment is 30-33kHz, and the ultrasonic power is 400-500W;
the secondary alkalization method comprises the steps of naturally rewarming the primary alkalization product to 3-8 ℃, adding a saturated sodium hydroxide aqueous solution under stirring, adjusting the concentration of sodium hydroxide to 35-40wt%, and performing secondary ultrasonic treatment for 10-20min to obtain a secondary alkalization product;
in the secondary alkalization, the frequency of the second ultrasonic treatment is 33-35kHz, and the ultrasonic power is 400-500W;
the primary carboxylation method comprises the steps of adding a predetermined amount of a carboxylation agent and a catalyst into the secondary alkali compound, heating to 40-50 ℃, preserving heat, and carrying out primary carboxylation reaction for 1-2 hours to obtain a primary carboxylate; in the process of primary carboxylation reaction, ultraviolet light with the wavelength of 385-395nm is adopted for radiation treatment;
the secondary carboxylation method comprises the steps of continuously heating the primary carboxylate to 50-60 ℃, preserving the temperature, and carrying out secondary carboxylation reaction for 30-60min to obtain a secondary carboxylate; in the process of secondary carboxylation, ultraviolet light with the wavelength of 390-400nm is adopted for radiation treatment;
the post-treatment method comprises the steps of cooling, pH adjusting and precipitating the secondary carboxylate, separating out solid matters, washing and drying to obtain the carboxymethyl chitosan.
2. The method for preparing carboxymethyl chitosan according to claim 1, wherein in the primary alkalization, the cooling rate after the first ultrasonic treatment is in the range of 0.2-0.5 ℃/min;
in the primary alkalization, the viscosity average molecular weight M eta of the chitosan is (35-40) multiplied by 10 4 The deacetylation degree is 75-85%, and the particle size is 0.1-0.3mm.
3. The method for preparing carboxymethyl chitosan according to claim 1, wherein in the primary carboxylation, the carboxylation agent is a mixture of chloroacetic acid and trichloroacetic acid, and the weight part ratio of the chloroacetic acid to the trichloroacetic acid is 1:3-4;
the addition amount of the carboxylating agent is 3-6 times of the weight of the chitosan in the primary alkalization.
4. The method for preparing carboxymethyl chitosan according to claim 1, wherein in the primary carboxylation, the catalyst is a mixture of lauryl dimethyl amine oxide and dodecyl trimethyl ammonium chloride, and the weight part ratio of the lauryl dimethyl amine oxide to the dodecyl trimethyl ammonium chloride is 2-3:1;
the addition amount of the catalyst is 0.2-0.5% of the weight of the chitosan in the primary alkalization.
5. The method for preparing carboxymethyl chitosan according to claim 1, wherein the post-treatment method comprises the steps of naturally cooling the secondary carboxylate to room temperature, adding the cooled secondary carboxylate into 3-5 times of anhydrous ethanol, adjusting the pH value to 6.8-7.2 with acetic acid, and standing until no solid is precipitated; and then centrifugally separating out solids, washing the solids by using sufficient ethanol solution until no chloride ions exist, leaching the solids by using 2-3 times of volume of absolute ethanol once, and drying the solids in vacuum until the weight of the solids is unchanged to obtain the carboxymethyl chitosan.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310212835.2A CN115873145B (en) | 2023-03-08 | 2023-03-08 | Preparation method of carboxymethyl chitosan |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310212835.2A CN115873145B (en) | 2023-03-08 | 2023-03-08 | Preparation method of carboxymethyl chitosan |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115873145A true CN115873145A (en) | 2023-03-31 |
| CN115873145B CN115873145B (en) | 2023-05-30 |
Family
ID=85761917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310212835.2A Active CN115873145B (en) | 2023-03-08 | 2023-03-08 | Preparation method of carboxymethyl chitosan |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115873145B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DD236738A1 (en) * | 1984-12-28 | 1986-06-18 | Finowtal Chem Fab | PROCESS FOR THE PREPARATION OF CARBOXYMETHYL CELLULOSE |
| JPH1072502A (en) * | 1996-08-30 | 1998-03-17 | Tsuyatsuku Kk | Production of water-soluble, partially acetylated chitosan solution |
| US20030125532A1 (en) * | 2001-11-28 | 2003-07-03 | Japan Atomic Energy Research Institute | Process for producing chitin derivatives and/or chitosan derivatives having a crosslinked structure |
| KR20030062081A (en) * | 2002-01-16 | 2003-07-23 | 주식회사 자광 | Manufacturing method of Water soluble chitosan blendmer for heavy metal binding agent and itself produced using the same |
| CN101747441A (en) * | 2008-12-19 | 2010-06-23 | 丹尼斯克（张家港）亲水胶体有限公司 | Preparation method of sodium carboxymethyl cellulose with high degree of substitution and high viscosity |
| KR20140136830A (en) * | 2013-05-21 | 2014-12-01 | 단국대학교 산학협력단 | N,O-Hydroxypropyl Chitosans and their alkanoic acid esters for liquid crystal and method for manufacturing the same |
| CN105153325A (en) * | 2015-09-16 | 2015-12-16 | 中华全国供销合作总社南京野生植物综合利用研究所 | Improved production process of carboxymethyl chitosan |
| CN106046200A (en) * | 2016-08-19 | 2016-10-26 | 沧州师范学院 | Preparation method of carboxymethyl chitosan |
| CN107759703A (en) * | 2017-11-17 | 2018-03-06 | 江南大学 | A kind of method that ultrasonic assistant prepares stalk carboxymethyl cellulose |
| WO2019043740A2 (en) * | 2017-01-24 | 2019-03-07 | Jordan University Of Science And Technology | Process of producing and method of using soluble high molecular-weight chitosan |
| CN111363064A (en) * | 2020-04-28 | 2020-07-03 | 东华大学 | Preparation method of carboxymethyl chitosan with high substitution degree and high molecular weight |
-
2023
- 2023-03-08 CN CN202310212835.2A patent/CN115873145B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DD236738A1 (en) * | 1984-12-28 | 1986-06-18 | Finowtal Chem Fab | PROCESS FOR THE PREPARATION OF CARBOXYMETHYL CELLULOSE |
| JPH1072502A (en) * | 1996-08-30 | 1998-03-17 | Tsuyatsuku Kk | Production of water-soluble, partially acetylated chitosan solution |
| US20030125532A1 (en) * | 2001-11-28 | 2003-07-03 | Japan Atomic Energy Research Institute | Process for producing chitin derivatives and/or chitosan derivatives having a crosslinked structure |
| KR20030062081A (en) * | 2002-01-16 | 2003-07-23 | 주식회사 자광 | Manufacturing method of Water soluble chitosan blendmer for heavy metal binding agent and itself produced using the same |
| CN101747441A (en) * | 2008-12-19 | 2010-06-23 | 丹尼斯克（张家港）亲水胶体有限公司 | Preparation method of sodium carboxymethyl cellulose with high degree of substitution and high viscosity |
| KR20140136830A (en) * | 2013-05-21 | 2014-12-01 | 단국대학교 산학협력단 | N,O-Hydroxypropyl Chitosans and their alkanoic acid esters for liquid crystal and method for manufacturing the same |
| CN105153325A (en) * | 2015-09-16 | 2015-12-16 | 中华全国供销合作总社南京野生植物综合利用研究所 | Improved production process of carboxymethyl chitosan |
| CN106046200A (en) * | 2016-08-19 | 2016-10-26 | 沧州师范学院 | Preparation method of carboxymethyl chitosan |
| WO2019043740A2 (en) * | 2017-01-24 | 2019-03-07 | Jordan University Of Science And Technology | Process of producing and method of using soluble high molecular-weight chitosan |
| CN107759703A (en) * | 2017-11-17 | 2018-03-06 | 江南大学 | A kind of method that ultrasonic assistant prepares stalk carboxymethyl cellulose |
| CN111363064A (en) * | 2020-04-28 | 2020-07-03 | 东华大学 | Preparation method of carboxymethyl chitosan with high substitution degree and high molecular weight |
Non-Patent Citations (3)
| Title |
|---|
| TANPONG CHAIWARIT ET AL.: "Development of Carboxymethyl Chitosan Nanoparticles Prepared by Ultrasound-Assisted Technique for a Clindamycin HCl Carrier", 《POLYMERS》 * |
| 付君善 等: "高取代度羧甲基壳聚糖的制备工艺研究", 《精细石油化工进展》 * |
| 奚廷斐 等: "《壳聚糖基海洋生物医用材料》", 上海：上海科学技术出版社 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115873145B (en) | 2023-05-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU689692B2 (en) | Chitosan salts and process for the preparation thereof | |
| US4929722A (en) | Acid decrystallization of aminopolysaccharides and derivatives thereof | |
| CN109293948B (en) | Hydrogel and preparation method and application thereof | |
| CN106975101B (en) | Nano-silver composite collagen medical dressing and preparation method thereof | |
| CN103071181A (en) | Hydrogel as well as preparation method and purpose of hydrogel | |
| CN109796606A (en) | A kind of self-healing hydrogel and preparation method thereof based on MULTIPLE DYNAMIC chemical bond | |
| CN107362386A (en) | A kind of Thermo-sensitive hydroxyl butyl chitosan hemostasis gel and application | |
| CN105670008A (en) | Water-soluble cross-linked HA (hyaluronic acid) dry powder and application | |
| CN111518296B (en) | Preparation method of chitosan membrane material | |
| Chatterjee et al. | Chitosan: source, chemistry, and properties | |
| Mali et al. | Synthesis and characterization of citric acid crosslinked carboxymethyl tamarind gum-polyvinyl alcohol hydrogel films | |
| CN115926200A (en) | Preparation method and application of enzyme-catalyzed double-crosslinked polymer composite hydrogel material | |
| CN115536920A (en) | Chitosan derivative-based wound repair hydrogel and preparation method and application thereof | |
| CN113855852B (en) | A repairing dressing containing Ginseng radix extract and its preparation method | |
| CN109762183A (en) | A kind of preparation method and products thereof of sodium trimetaphosphate cross-linked hyaluronic acid gel | |
| CN107915850B (en) | Selenium-containing chitosan hydrogel and preparation method, degradation method and application thereof | |
| CN115873145A (en) | Preparation method of carboxymethyl chitosan | |
| CN106310348B (en) | Starch/poloxamer composite styptic powder and preparation method thereof | |
| CN109354632B (en) | Carboxymethyl aminopolysaccharide derivative and preparation method and application thereof | |
| CN112618785A (en) | Porous antibacterial hydrogel dressing and preparation method thereof | |
| CN110317280A (en) | A kind of different degree of substitution Preparation Technology of Carboxymethyl-chitosan | |
| CN116535540B (en) | Quaternized modified chitin, sponge thereof, preparation method of porous microsphere and application of quaternized modified chitin | |
| CN117357564A (en) | Novel protective agent for promoting ulcer surface healing | |
| CN117050341B (en) | Single-phase room-temperature injectable temperature-sensitive chitosan hydrogel and preparation method thereof | |
| CN111359006B (en) | Medical high-strength high-antibacterial-property enzymolysis-resistant gel film and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |