CN114989315B

CN114989315B - Preparation method of biomass-based antioxidant material

Info

Publication number: CN114989315B
Application number: CN202210774415.9A
Authority: CN
Inventors: 李唯; 梁敏敏; 李怡薇; 杜洁莹
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2022-07-01
Filing date: 2022-07-01
Publication date: 2023-03-17
Anticipated expiration: 2042-07-01
Also published as: CN114989315A

Abstract

The invention discloses a preparation method of a biomass-based antioxidant material, which comprises the following steps: 1) Mixing carbon tetrachloride, eugenol and silver oxide according to a certain molar ratio for reaction, and filtering to obtain a reaction intermediate; 2) Soaking a biomass material containing hydroxyl in a polar hydrophilic solvent, adding a reaction intermediate, and completing an oil bath reaction under the condition of high-temperature heating to obtain the biomass-based antioxidant material. The biomass-based antioxidant material prepared by the invention overcomes the defects of volatility, potential toxicity and the like of eugenol; after the biomass material is swelled by the polar hydrophilic solvent, the hydroxyl reaction activity is enhanced, and the grafting ratio of the eugenol is improved; the biomass-based antioxidant material has high antioxidant performance and hydrophobic performance, and a series of advantages of environmental protection, reproducibility, degradability and the like, and the application of the biomass-based antioxidant material in various fields is widened.

Description

Preparation method of biomass-based antioxidant material

Technical Field

The invention belongs to the field of materials, and relates to a preparation method of an antioxidant material, in particular to a preparation method of a biomass-based antioxidant material.

Background

The biomass material can be used as a substitute of a plastic product, has the advantages of low cost, excellent mechanical property, recoverability, degradability and the like, and is widely applied to various fields of packaging, daily chemicals, food and the like. At present, biomass materials such as regenerated cellulose films are used in the field of functional packaging such as antibacterial property by some researchers, and further intensive research on antioxidant property is needed.

Eugenol, as a natural antioxidant, has antibacterial, anti-inflammatory and analgesic effects, is widely concerned in academia and industry, and is widely applied to the fields of food, cosmetics, medicine and the like. However, eugenol is a small molecule, easily penetrates cell membranes, influences cell metabolism and has cytotoxicity. In addition, the volatility of eugenol is also an urgent problem to be solved. Taking a regenerated cellulose film as an example, studies have reported that eugenol can be grafted on cellulose, but the reaction utilizes the phenolic hydroxyl group of eugenol, and may have an influence on the antioxidant property. Based on this, how to retain phenolic hydroxyl group in the reaction of the biomass material and the eugenol, endow the eugenol with antioxidant property to the biomass material, and simultaneously reduce the volatility and potential toxicity of the eugenol is the problem to be solved by the invention.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a preparation method of a biomass-based antioxidant material, so that the performance of the biomass material is improved, and the application field is expanded.

The above purpose is realized by the following technical scheme:

a preparation method of a biomass-based antioxidant material comprises the following steps:

1) Heating carbon tetrachloride as a reaction solvent and silver oxide as a catalyst to fully react eugenol, and then filtering to obtain a reaction intermediate; the grafting reaction formula of the eugenol and the biomass material A is shown in figure 1;

2) Polar hydrophilic reagent is used as solvent to swell the biomass material, then reaction intermediate is added, and oil bath reaction is carried out, thus obtaining the biomass-based antioxidant material.

Further, the molar ratio of the silver oxide to the eugenol in the step 1) is 1-15.

Further, the heating temperature in the step 1) is 50-80 ℃.

Further, the polar hydrophilic reagent of step 2) includes but is not limited to: dimethyl sulfoxide, nitroethane, dimethylformamide, dimethylacetamide, tetrahydrofuran and N-methylpyrrolidone.

Further, the biomass material of step 2) includes but is not limited to: cellulose, chitin, chitosan, starch, hemicellulose, agar and protein.

Further, the molar ratio of the biomass material to the eugenol in the step 2) is 1.

Further, the oil bath reaction conditions in the step 2) are as follows: oil bath reaction at 70-100 deg.c for 0.2-72 hr.

The invention also discloses a biomass-based antioxidant material prepared by any one of the preparation methods.

Compared with the prior art, the invention has the following beneficial effects:

1) The invention solves the defects of volatility, potential toxicity and the like of the eugenol;

2) In the invention, after the biomass material is swelled by the polar hydrophilic solvent, the hydroxyl reaction activity is enhanced, and the grafting rate of the eugenol is improved;

3) The biomass-based antioxidant material prepared by the invention has higher antioxidant performance and hydrophobic performance;

4) The biomass material has a series of advantages of environmental protection, reproducibility, degradability and the like, but the biomass material does not have oxidation resistance, and the application field is limited.

Drawings

FIG. 1 shows the grafting reaction formula of eugenol and biomass material A in step 1) of the invention.

FIG. 2 is an oxidation resistance graph of pure regenerated cellulose membranes and cellulose eugenol composite membranes with different reaction times.

FIG. 3 is a TGA graph of freeze-dried pure regenerated cellulose membranes (n-RC) after liquid nitrogen pretreatment and cellulose eugenol composite membranes with reaction times of 0.5 (n-RCE 0.5), 3 (n-RCE 3), 7 (n-RCE 7), 24 (n-RCE 24) and 48 hours (n-RCE 48).

Fig. 4 is a contact angle image of a pure regenerated cellulose film (a) and a cellulose eugenol composite film (b) with a reaction time of 48 hours.

FIG. 5 shows the cell absorbance (OD) values and cell proliferation rates of a control group and an experimental group of a pure regenerated cellulose membrane (n-RC) and a cellulose eugenol composite membrane (n-RCE 0.5) with a reaction time of 0.5 hour.

Detailed Description

The invention is further illustrated by the following examples. These embodiments are merely illustrative of the present invention and are not intended to limit the scope of the present invention. In addition, after reading the teaching of the present invention, those skilled in the art can make various changes or modifications to the invention, and these equivalents also fall within the scope of the claims appended to the present application.

Example 1

1) Using carbon tetrachloride as a reaction solvent and silver oxide as a catalyst to enable eugenol to fully react at 65 ℃, and then filtering to obtain a reaction intermediate. The specific operation is as follows:

320ml of carbon tetrachloride and 2g of eugenol and 12g of silver oxide were added to a 500ml round bottom flask equipped with a rotor and a condenser, and reacted for 11min under an oil bath at 65 ℃. And adding diatomite into the sand core suction filtering funnel, and performing suction filtration under reduced pressure to remove silver oxide to obtain a reaction intermediate.

2) Using dimethyl sulfoxide as a solvent to swell the regenerated cellulose membrane, then adding the reaction intermediate obtained in the step 1), and carrying out oil bath reaction at 90 ℃ for 0.5h, wherein the specific operation is as follows:

to a 500ml round bottom flask was added 128ml of dimethyl sulfoxide solvent, and to the flask was added 0.3g of regenerated cellulose film. Adding the reaction intermediate obtained in step 1) into a round-bottom flask. After this time the round bottom flask was fitted with a condenser and reacted for 0.5h in an oil bath at 90 ℃.

Example 2

1) Using carbon tetrachloride as a reaction solvent and silver oxide as a catalyst to enable eugenol to fully react at 70 ℃, and then filtering to obtain a reaction intermediate. The specific operation is as follows:

320ml of carbon tetrachloride and 2g of eugenol and 12g of silver oxide were added to a 500ml round bottom flask equipped with a rotor and a condenser, and reacted for 11min under an oil bath at 70 ℃. And adding diatomite into the sand core suction filtering funnel, and performing reduced pressure suction filtration to remove silver oxide to obtain a reaction intermediate.

2) Using dimethyl sulfoxide as a solvent to swell starch, then adding the reaction intermediate obtained in the step 1), and carrying out oil bath reaction at 90 ℃ for 48 hours, wherein the specific operation is as follows:

to a 500ml round bottom flask was added 128ml of dimethyl sulfoxide solvent and to the flask was added 0.1g of starch. Adding the reaction intermediate obtained in step 1) into a round-bottom flask. Then, a condenser tube was attached to the round-bottom flask, and the reaction was carried out in an oil bath at 90 ℃ for 48 hours.

Example 3

320ml of carbon tetrachloride and 2g of eugenol and 10g of silver oxide were added to a 500ml round bottom flask equipped with a rotor and a condenser, and reacted for 20min under an oil bath at 65 ℃. And adding diatomite into the sand core suction filtering funnel, and performing reduced pressure suction filtration to remove silver oxide to obtain a reaction intermediate.

2) Using tetrahydrofuran as a solvent to swell the chitosan, and then adding the reaction intermediate obtained in the step 1) to perform oil bath reaction for 72 hours at 100 ℃, wherein the specific operation is as follows:

150ml of tetrahydrofuran solvent was added to a 500ml round bottom flask and 0.6g of chitosan was added to the flask. Adding the reaction intermediate obtained in step 1) into a round-bottom flask. After that, a condenser tube was attached to the round-bottom flask, and the reaction was carried out in an oil bath at 100 ℃ for 72 hours.

Comparative example 1

Preparation of pure regenerated cellulose membranes

(1) 9 g of LiOH and 12g of urea are mixed, 100 g of water is added, and a LiOH/urea solution is prepared. 3.7 g of cellulose powder were dissolved in a LiOH/urea solution and the resulting cellulose suspension was placed in a refrigerator and frozen at-20 ℃ for 24 hours. Taking out and mechanically stirring at room temperature to obtain viscous solution, centrifuging at 8000rpm and 4 deg.C for 5 min to remove bubbles to obtain transparent cellulose solution;

(2) The cellulose solution was pushed off the glass plate and immersed in an acidic solution (5% ₂ SO ₄ ) In (b), a translucent cellulose film is obtained, which is washed with distilled water untilAnd (4) the product is neutral.

(3) The cellulose membrane can be dried by three drying methods, namely natural drying, pretreatment freeze drying at-80 ℃ and liquid nitrogen pretreatment freeze drying.

Test example 1

Evaluation of product Properties

1.1 evaluation of Oxidation resistance

FIG. 2 shows the absorbance of DPPH solutions of pure regenerated cellulose membranes and cellulose eugenol composite membranes with different reaction times, and the oxidation resistance values are labeled. As shown in fig. 2, it can be seen that cellulose itself does not have oxidation resistance, which is imparted by grafting eugenol. The oxidation resistance of different reaction time is kept above 90%.

1.2 evaluation of thermal stability

FIG. 3 is a thermogravimetric plot of pure regenerated cellulose membranes and cellulose eugenol composite membranes with reaction times of 0.5, 3, 7, 24 and 48 hours. The n-RCE7 is weightless firstly and is about 200 ℃, and the weightless temperature of the modified membrane of the RC membrane and other reaction time is about 270 ℃. The final quality of the RC film is stabilized at about 10%, and the final quality of the modified film is stabilized at 20% -35%, and the RC film has the following size sequence: 48 > 3 > 7 > 24 > 0.5. Compared with a pure regenerated cellulose membrane, the thermal stability of the composite membrane is improved, and the composite membrane is influenced by reaction time.

1.3 evaluation of hydrophobic Properties

The hydrophilicity and hydrophobicity of the composite membrane can be known by testing the contact angle of the surface of the membrane. Fig. 4 is a contact angle image of a pure regenerated cellulose film and a cellulose eugenol composite film with a reaction time of 48 hours. Cellulose is a very hydrophilic material and water drops on the surface are quickly absorbed, so that the contact angle is difficult to measure accurately. When eugenol is added to modify the cellulose membrane, as shown in fig. 4, the contact angle value is greatly increased, which indicates that the membrane surface is gradually changed from hydrophilic to hydrophobic.

1.4 cytotoxicity assays

FIG. 5 shows the cell absorbance (OD) values and cell proliferation rates of a control group and an experimental group of a pure regenerated cellulose membrane (n-RC) and a cellulose eugenol composite membrane (n-RCE 0.5) with a reaction time of 0.5 hour. The ordinate corresponds to absorbance values, and the cell proliferation rate (RGR) is plotted on a bar graph. As shown in FIG. 5, the cell proliferation rate of both n-RC and n-RCE0.5 is more than 100%, the cytotoxicity is 0 grade, and the requirement of biocompatibility is met.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.

Claims

1. A preparation method of a biomass-based antioxidant material comprises the following steps:

1) Heating to 50-80 ℃ by using carbon tetrachloride as a reaction solvent and silver oxide as a catalyst to fully react the eugenol, wherein the molar ratio of the silver oxide to the eugenol is 1-15, and then filtering to obtain a mixed solution of a reaction intermediate and the carbon tetrachloride;

2) And (2) swelling the biomass material containing hydroxyl by using a polar hydrophilic reagent as a solvent, adding a mixed solution of a reaction intermediate and carbon tetrachloride, wherein the molar ratio of the biomass material containing hydroxyl to eugenol is 1-50, and performing oil bath reaction at 70-100 ℃ for 0.2-72 hours to obtain the biomass-based antioxidant material.

2. The production method according to claim 1, wherein:

step 2) the polar hydrophilic reagent comprises: dimethyl sulfoxide, nitroethane, dimethylformamide, dimethylacetamide, tetrahydrofuran and N-methylpyrrolidone.

3. The production method according to claim 1, wherein:

step 2) the hydroxyl-containing biomass material comprises: cellulose, chitin, chitosan, starch, hemicellulose, agar and protein.

4. A biomass-based antioxidant material produced by the production method according to any one of claims 1 to 3.