A modified camellia oil and its application in film preparation

Abstract

The present invention provides a modified camellia oil and its application in film preparation. The preparation method of the modified camellia oil comprises the following steps: esterifying camellia oil with a sufficient amount of methanol to obtain transesterified camellia oil; mixing transesterified camellia oil with octenyl succinic anhydride in a reaction solvent to obtain a reaction system A; adding triethylamine and catalyst 4-dimethylaminopyridine to the reaction system A, reacting at 90-120°C for 60-90 minutes; adding alkali solution to adjust the pH to 7.0-7.5 after cooling to 50-65°C; removing the reaction solvent. The structure of the modified camellia oil after esterification has a hydrophilic group and a hydrophobic group, and the main structure is a main chain structure, which can better improve the mechanical properties and degradable properties of the film and artificial leather. After the camellia oil is esterified and modified by octenyl succinic anhydride, it is matched with oxidized cellulose and sodium alginate to prepare a film. The obtained film has better mechanical properties, better oxygen isolation effect and degradable properties, and has a good application scenario in food packaging.

Description

Technical Field

[0001] The invention relates to the field of modified preparation and application of camellia oil, and in particular to modified camellia oil and application thereof in film preparation. Background Art

[0002] Camellia oleifera is one of the four major woody oil plants in my country. Its main product, tea oil, has rich nutritional value and health benefits and has been widely used in the fields of food and daily chemicals. During the processing of camellia seeds, camellia oleifera residues rich in bioactive substances are produced, including camellia oleifera shells and camellia oleifera cakes. At present, many scholars have conducted in-depth research on the bioactive substances in camellia oleifera residues. Camellia oil is also used as a fatliquor for leather. However, other uses still need to be improved. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a modified camellia oil and its application in film preparation.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a modified camellia oil, and the preparation method of the modified camellia oil comprises the following steps:

[0005] (1) mixing camellia oil with sufficient methanol and catalyst 4-dimethylaminopyridine at 80-100° C. for reaction for 60-90 minutes, then removing excess methanol to obtain transesterified camellia oil;

[0006] (2) mixing the transesterified camellia oil and octenyl succinic anhydride in a reaction solvent to obtain a reaction system A;

[0007] (3) adding triethylamine (TEA) and catalyst 4-dimethylaminopyridine (DMAP) to reaction system A, and reacting at 90-120° C. for 60-90 minutes;

[0008] (4) cooling to 50-65°C and adding alkali solution to adjust the pH to 7.0-7.5;

[0009] (5) Removing the reaction solvent in the system of step (4) to obtain modified camellia oil.

[0010] The modified camellia oil is made from camellia oil, which contains a large number of carboxyl functional groups and hydroxyl functional groups. The carboxyl functional groups of camellia oil are first modified by esterification reaction using methanol to obtain transesterified camellia oil. The transesterified camellia oil is then subjected to esterification reaction with octenyl succinic anhydride to introduce a long carbon chain ester structure. The reaction formula is shown in Ⅰ to obtain modified camellia oil.

[0011]

[0012] Wherein R represents the groups other than hydroxyl groups in the transesterified camellia oil.

[0013] The structure of modified camellia oil after esterification has hydrophilic groups and hydrophobic groups, and the main structure is a main chain structure. Its application in the preparation of cellulose film and cellulose artificial leather can better improve the mechanical properties and degradability of the film and artificial leather.

[0014] Preferably, in step (1), camellia oil is reacted with a sufficient amount of methanol in a reaction solvent, N,N-dimethylformamide, and the solvent is removed after the reaction is completed.

[0015] Preferably, in step (2), the mass ratio of the transesterified camellia oil to octenyl succinic anhydride is 1:(0.2-0.35), and the reaction solvent is N,N-dimethylformamide.

[0016] The study found that when the mass ratio of ester-transferred camellia oil to octenyl succinic anhydride is 1:(0.2-0.35), the modified camellia oil has a better effect of improving the mechanical properties and degradability of films and artificial leather.

[0017] Preferably, in the step (3), the amount of triethylamine used is 1% to 2% of the mass of the transesterified camellia oil; the amount of 4-dimethylaminopyridine used is 0.5% to 1% of the mass of the transesterified camellia oil.

[0018] Preferably, the method for removing the reaction solvent in the system of step (4) is: removing the reaction solvent by low-pressure evaporation at a temperature below 50°C.

[0019] The present invention also provides a method for preparing the modified camellia oil, which comprises the following steps:

[0020] (1) mixing camellia oil with sufficient methanol and catalyst 4-dimethylaminopyridine at 80-100° C. for reaction for 60-90 minutes, and then removing excess methanol to obtain transesterified camellia oil;

[0021] (2) mixing the transesterified camellia oil and octenyl succinic anhydride in a reaction solvent to obtain a reaction system A;

[0022] (3) adding triethylamine and catalyst 4-dimethylaminopyridine to reaction system A, and reacting at 90-120° C. for 60-90 minutes;

[0023] (4) cooling to 50-65°C and adding alkali solution to adjust the pH to 7.0-7.5;

[0024] (5) Removing the reaction solvent in the system of step (4) to obtain modified camellia oil.

[0025] Preferably, in step (2), the mass ratio of the transesterified camellia oil to octenyl succinic anhydride is 1:(0.2-0.35), and the reaction solvent is N,N-dimethylformamide.

[0026] Preferably, in the step (3), the amount of triethylamine used is 1% to 2% of the mass of the transesterified camellia oil; the amount of 4-dimethylaminopyridine used is 0.5% to 1% of the mass of the transesterified camellia oil.

[0027] Preferably, in step (5), the method for removing the reaction solvent in the system of step (4) is: removing the reaction solvent by low-pressure evaporation at a temperature below 50°C.

[0028] The present invention also provides a film prepared by using modified camellia oil, and the preparation method of the film comprises the following steps:

[0029] (I) dissolving cellulose and lithium chloride in N,N-dimethylacetamide, heating and stirring at 90-105° C. for 45-75 minutes, and then stirring at 25-30° C. for 4-8 hours to obtain a cellulose suspension;

[0030] (II) adding deionized water to the cellulose suspension, stirring and filtering, washing with deionized water, drying, and mechanically crushing to obtain modified cellulose A;

[0031] (III) mixing modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide in deionized water to obtain a mixed aqueous solution A; wherein the mass ratio of modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide is 1:(0.08-0.12):(0.1-0.15);

[0032] (IV) mixing a sodium hypochlorite aqueous solution having a pH of 9.8 to 10.2 with the mixed aqueous solution A for reaction, adding sodium hydroxide during the reaction to adjust and maintain the pH of the reaction system at 9.8 to 10.2, and adding ethanol to terminate the reaction after the pH no longer needs sodium hydroxide adjustment, filtering and washing with water to obtain a suspension of modified cellulose B;

[0033] (V) stirring the suspension of modified cellulose B, the modified camellia oil as claimed in any one of claims 1 to 5, and an aqueous solution of sodium alginate in a constant temperature water bath at 45 to 55° C. for 15 to 30 minutes until fully mixed to obtain a mixed solution B;

[0034] (VI) After the mixed solution B is filtered and formed into a wet film, ion cross-linking is carried out in a calcium chloride aqueous solution with a mass concentration of 2.5% to 3.5%, and after standing at 25 to 30° C. for 18 to 24 hours, the film is dried to obtain a film prepared using modified camellia oil.

[0035] Through research, it was found that after camellia oil was modified by esterification with octenylsuccinic anhydride, it was combined with oxidized cellulose and sodium alginate to prepare a film. The obtained film has better mechanical properties, better oxygen barrier effect and biodegradability, and has a good application scenario in food packaging.

[0036] Preferably, in the step (V), the amount of the suspension of modified cellulose B, the modified camellia oil as described above, and sodium alginate is, measured on a dry basis of the suspension of modified cellulose B, 100 parts by weight of the suspension of modified cellulose B, 10 to 25 parts by weight of the modified camellia oil as described above, and 25 to 50 parts by weight of sodium alginate, and a 1.5% to 2.5% aqueous solution of sodium alginate is mixed with the suspension of modified cellulose B and the modified camellia oil as described above.

[0037] The combination of the weight of the above-mentioned oxidized modified cellulose B, sodium alginate and modified camellia oil makes the film have more excellent mechanical properties, better oxygen barrier effect and degradability.

[0038] Preferably, in step (I), the usage ratio of cellulose, lithium chloride and N,N-dimethylacetamide is: (2-4) g cellulose: (2-3) g lithium chloride: 100 mL N,N-dimethylacetamide.

[0039] Preferably, in step (IV), the amount of sodium hypochlorite used is such that the weight ratio of sodium hypochlorite to modified cellulose A is (0.8-1.2):10, the mass concentration of the sodium hypochlorite aqueous solution is 10%-15%, and the pH is adjusted to 9.8-10.2 with concentrated hydrochloric acid.

[0040] The present invention also provides a method for preparing a film using modified camellia oil, the preparation method comprising the following steps:

[0041] (I) dissolving cellulose and lithium chloride in N,N-dimethylacetamide, heating and stirring at 90-105° C. for 45-75 minutes, and then stirring at 25-30° C. for 4-8 hours to obtain a cellulose suspension;

[0042] (II) adding deionized water to the cellulose suspension, stirring and filtering, washing with deionized water, drying, and mechanically crushing to obtain modified cellulose A;

[0043] (III) mixing modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide in deionized water to obtain a mixed aqueous solution A; wherein the mass ratio of modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide is 1:(0.08-0.12):(0.1-0.15);

[0044] (IV) mixing a sodium hypochlorite aqueous solution having a pH of 9.8 to 10.2 with the mixed aqueous solution A for reaction, adding sodium hydroxide during the reaction to adjust and maintain the pH of the reaction system at 9.8 to 10.2, and adding ethanol to terminate the reaction after the pH no longer needs sodium hydroxide adjustment, filtering and washing with water to obtain a suspension of modified cellulose B;

[0045] (V) stirring the suspension of modified cellulose B, the modified camellia oil as claimed in any one of claims 1 to 5, and an aqueous solution of sodium alginate in a constant temperature water bath at 45 to 55° C. for 15 to 30 minutes until fully mixed to obtain a mixed solution B;

[0046] (VI) After the mixed solution B is filtered and formed into a wet film, ion cross-linking is carried out in a calcium chloride aqueous solution with a mass concentration of 2.5% to 3.5%, and after standing at 25 to 30° C. for 18 to 24 hours, the film is dried to obtain a film prepared using modified camellia oil.

[0047] Preferably, in the step (V), the amount of the suspension of modified cellulose B, the modified camellia oil as described above, and sodium alginate is, measured on a dry basis of the suspension of modified cellulose B, 100 parts by weight of the suspension of modified cellulose B, 10 to 25 parts by weight of the modified camellia oil as described above, and 25 to 50 parts by weight of sodium alginate, and a 1.5% to 2.5% aqueous solution of sodium alginate is mixed with the suspension of modified cellulose B and the modified camellia oil as described above.

[0048] The combination of the weight of the above-mentioned oxidized modified cellulose B, sodium alginate and modified camellia oil makes the film have more excellent mechanical properties, better oxygen barrier effect and degradability.

[0049] Preferably, in step (I), the usage ratio of cellulose, lithium chloride and N,N-dimethylacetamide is: (2-4) g cellulose: (2-3) g lithium chloride: 100 mL N,N-dimethylacetamide.

[0050] Preferably, in step (IV), the amount of sodium hypochlorite used is such that the weight ratio of sodium hypochlorite to modified cellulose A is (0.8-1.2):10, the mass concentration of the sodium hypochlorite aqueous solution is 10%-15%, and the pH is adjusted to 9.8-10.2 with concentrated hydrochloric acid.

[0051] The cellulose raw material can be wood cellulose, bamboo cellulose or camellia shell cellulose.

[0052] The beneficial effects of the present invention are as follows: the present invention provides a modified camellia oil and its application in the preparation of thin films, providing better application purposes for camellia oil and its byproducts. The structure of the modified camellia oil of the present invention after esterification has a hydrophilic group and a hydrophobic group, and the main structure is a main chain structure. When it is applied to the preparation of cellulose film and cellulose artificial leather, the mechanical properties and degradability of the film and artificial leather can be better improved. After the camellia oil is esterified and modified with octenyl succinic anhydride, it is combined with oxidized cellulose and sodium alginate to prepare a film. The obtained film has better mechanical properties, better oxygen barrier effect and degradability, and has a good application scenario in food packaging. DETAILED DESCRIPTION

[0053] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0054] Example 1

[0055] As a modified camellia oil according to an embodiment of the present invention, the preparation method of the modified camellia oil comprises the following steps:

[0056] (1) mixing camellia oil with sufficient amount of methanol and catalyst 4-dimethylaminopyridine in a reaction solvent N,N-dimethylformamide, reacting at 90° C. for 75 minutes, and then removing excess methanol and reaction solvent to obtain transesterified camellia oil;

[0057] (2) mixing the transesterified camellia oil and octenyl succinic anhydride in a reaction solvent, N,N-dimethylformamide, to obtain a reaction system A; the mass ratio of the transesterified camellia oil to the octenyl succinic anhydride is 1:0.20;

[0058] (3) adding triethylamine and catalyst 4-dimethylaminopyridine to reaction system A, and reacting at 90-120° C. for 60-90 minutes; the amount of triethylamine used is 1.5% of the mass of the transesterified camellia oil, and the amount of 4-dimethylaminopyridine used is 0.8% of the mass of the transesterified camellia oil;

[0059] (4) cooling to 60°C and adding alkali solution to adjust the pH to 7.2;

[0060] (5) removing the reaction solvent in the system of step (4) by low-pressure evaporation at a temperature below 50° C. to obtain modified camellia oil.

[0061] Example 2

[0062] As a modified camellia oil of an embodiment of the present invention, the only difference between this embodiment and embodiment 1 is that the mass ratio of the transesterified camellia oil to octenyl succinic anhydride is 1:0.25.

[0063] Example 3

[0064] As a modified camellia oil of an embodiment of the present invention, the only difference between this embodiment and embodiment 1 is that the mass ratio of the transesterified camellia oil to octenyl succinic anhydride is 1:0.30.

[0065] Example 4

[0066] As a modified camellia oil of an embodiment of the present invention, the only difference between this embodiment and embodiment 1 is that the mass ratio of the transesterified camellia oil to octenyl succinic anhydride is 1:0.35.

[0067] The transesterified camellia oil in step (1) of Examples 1-4 was uniformly prepared for subsequent reactions and the mass yield of the transesterified camellia oil and camellia oil was calculated.

[0068] Example 5

[0069] As a film prepared by using modified camellia oil of the present invention, the preparation method of the film comprises the following steps:

[0070] (I) dissolving cellulose and lithium chloride in N,N-dimethylacetamide, heating and stirring at 95°C for 50 minutes, and then stirring at 25°C for 5 hours to obtain a cellulose suspension; the amount ratio of cellulose, lithium chloride and N,N-dimethylacetamide is: 3g cellulose: 2.5g lithium chloride: 100mL N,N-dimethylacetamide;

[0071] (II) adding deionized water to the cellulose suspension, stirring and filtering, washing with deionized water, drying, and mechanically crushing to obtain modified cellulose A;

[0072] (III) mixing modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide in deionized water to obtain a mixed aqueous solution A, wherein the mass ratio of modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide is 1:0.10:0.12;

[0073] (IV) the mass concentration of the sodium hypochlorite aqueous solution is 12%, the pH is adjusted to 10 with concentrated hydrochloric acid, the sodium hypochlorite aqueous solution with a pH of 10 is mixed with the mixed aqueous solution A for reaction, sodium hydroxide is added during the reaction to adjust the pH of the reaction system to maintain 10, ethanol is added to terminate the reaction after the pH is no longer required to be adjusted by sodium hydroxide, and the suspension of modified cellulose B is obtained after filtering and washing with water; the weight ratio of sodium hypochlorite to modified cellulose A is 1:10;

[0074] (V) Stirring the suspension of modified cellulose B, the modified camellia oil prepared as in Example 1, and the aqueous sodium alginate solution in a 50° C. constant temperature water bath for 20 minutes until fully mixed to obtain a mixed solution B; the amount of the suspension of modified cellulose B, the modified camellia oil as in Example 1, and the sodium alginate is, based on the dry basis of the suspension of modified cellulose B, 100 parts by weight of the suspension of modified cellulose B, 15 parts by weight of the modified camellia oil, and 35 parts by weight of the sodium alginate, and a 2% aqueous solution of the sodium alginate is mixed with the suspension of modified cellulose B and the modified camellia oil;

[0075] (VI) The mixed solution B is filtered and formed into a wet film, which is then ionically cross-linked in a 3% calcium chloride aqueous solution. After standing at 25° C. for 18 hours, the film is dried to obtain a film prepared using modified camellia oil.

[0076] Example 6

[0077] As a film prepared by using modified camellia oil of the present invention, the only difference between this example and Example 5 is that the modified camellia oil prepared by Example 2 is used to replace the modified camellia oil prepared by Example 1.

[0078] Example 7

[0079] As a film prepared by using modified camellia oil of the present invention, the only difference between this example and Example 5 is that the modified camellia oil prepared by Example 3 is used to replace the modified camellia oil prepared by Example 1.

[0080] Example 8

[0081] As a film prepared by using modified camellia oil of the present invention, the only difference between this example and Example 5 is that the modified camellia oil prepared by Example 4 is used to replace the modified camellia oil prepared by Example 1.

[0082] Example 9

[0083] As a film prepared by using modified camellia oil of the present invention, the only difference between this embodiment and embodiment 5 is that the amount of the suspension of modified cellulose B, modified camellia oil and sodium alginate is, measured on a dry basis of the suspension of modified cellulose B, 100 parts by weight of the dry basis of the suspension of modified cellulose B, 25 parts by weight of modified camellia oil and 25 parts by weight of sodium alginate.

[0084] Comparative Example 1

[0085] As a comparative example of the present invention, a film is prepared by using modified camellia oil. The only difference between this comparative example and Example 5 is that the modified camellia oil prepared in Example 1 is replaced by camellia oil.

[0086] Comparative Example 2

[0087] As a comparative example of the present invention, a film is prepared using modified camellia oil. The only difference between this comparative example and Example 5 is that the modified camellia oil prepared in Example 1 is replaced by the transesterified camellia oil prepared in step (1) of Example 1.

[0088] Comparative Example 3

[0089] As a comparative example of the present invention, a film is prepared by using modified camellia oil. The only difference between this comparative example and Example 5 is that the suspension of modified cellulose B is replaced by cellulose solution.

[0090] Comparative Example 4

[0091] As a comparative example of the present invention, a film is prepared using modified camellia oil. The only difference between this comparative example and Example 5 is that steps (III) and (IV) are not performed, and modified cellulose A replaces modified cellulose B.

[0092] Comparative Example 5

[0093] As a comparative example of the present invention, a film prepared by using modified camellia oil is used. The only difference between this comparative example and Example 5 is that the film is prepared by using 100 parts by weight of a suspension of modified cellulose B on a dry basis and 25 parts by weight of sodium alginate, without adding modified camellia oil or camellia oil.

[0094] Experimental methods

[0095] 1. Experimental materials

[0096] Camellia oil was purchased from Hunan Yamei Camellia Oil Co., Ltd., cellulose was purchased from Aladdin, and the rest were analytical grade reagents.

[0097] 2. Substitution and esterification rate of modified camellia oil.

[0098] The substitution esterification rate of the product was calculated by the alkaline hydrolysis-acid back titration method based on the neutralization of the alkali and the carboxylic acid after the alkaline hydrolysis of the ester. First, 0.5 g of the samples of Examples 1-4 were taken respectively, 20 mL of dimethyl sulfoxide was added, and after magnetic stirring for 1 h, 100 mL of 0.25 mol / L NaOH solution was added, and heated to 70° C. in a constant temperature magnetic stirring water bath, and magnetic stirring was performed for 12 h, 2 to 3 drops of phenolphthalein indicator were added, and the excess NaOH in the reaction beaker was titrated with 0.25 mol / L HCl solution. The titration was terminated when the phenolphthalein turned pink, and the HCl used for the titration was recorded. The same test was performed with (0.5 / 1.78) g of the ester-exchanged camellia oil prepared in step (1) of Example 1 as a control.

[0099] Since camellia oil contains a variety of components and is a mixture, the degree of substitution of its functional groups cannot be calculated, but the octenyl succinic anhydride substitution esterification rate of camellia oil can still be calculated. Excessive NaOH is added. According to the law of conservation of matter, the total amount of NaOH is divided into three parts. After alkaline hydrolysis of the ester, one part of NaOH reacts with the carboxyl group contained in the camellia oil, another part reacts with the titrated HCl, and another part reacts with the hydrolyzed octenyl succinic acid. This part represents the octenyl succinic anhydride substitution esterification degree of camellia oil. In the preparation of Example 1, it can be known by measurement that 1g of the transesterified camellia oil prepared in step (1) can be reacted to obtain 1.78g of the final modified camellia oil of Example 1, so the ratio of 1g of the transesterified camellia oil prepared in step (1) to 1.78g of the final modified camellia oil of Example 1 is used as a control for the experiment.

[0100] Through the titration of the control group, the molar amount n0 of carboxyl groups contained in the ester-exchanged camellia oil of the control sample can be calculated according to the total amount of alkali and HCl consumption.

[0101] Through the titration of the experimental group, record the molar amount of HCl consumed n2 and the total mass of sodium hydroxide n 总 , then the amount of octenyl succinic acid, that is, the degree of octenyl succinic anhydride substitution esterification of camellia oil is n1 = (n 总 -n0-n2) / 2. According to the feed and output ratio of camellia oil, transesterified camellia oil and final modified camellia oil, in the samples of Examples 1-4, DmoL octenyl succinic anhydride groups are substituted per 100g of camellia oil, denoted as D, as shown in Table 1, which can represent the octenyl succinic anhydride substitution esterification degree of camellia oil.

[0102] Table 1 Degree of octenyl succinic anhydride substitution esterification of modified camellia oil

[0103] sample Octenyl succinic anhydride functional group substitution molar number D Example 1 0.072 Example 2 0.106 Example 3 0.128 Example 4 0.143

[0104] 3. Properties of films prepared with modified camellia oil.

[0105] (I) Mechanical properties

[0106] According to GB / T1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for films and sheets", the mechanical properties of the film were determined using a universal mechanical testing machine. First, the thickness of the film was measured; then the film was cut into dumbbell-shaped strips with a length of 35 mm and a narrow width of 2 mm using a dumbbell cutter. The clamp spacing was adjusted to 20 mm, and a 100N sensor was used to measure the tensile strength and elongation of the TOCN / SA-x film at a tensile rate of 1 mm / min. At least 3 parallel samples were measured for each sample, and the arithmetic mean was taken. The results are shown in Table 2.

[0107] Table 2 Mechanical properties of films prepared with modified camellia oil

[0108] sample Thickness / mm Tensile strength / Mpa Elongation after break % Example 5 0.196 79.8 9.76 Example 6 0.199 81.8 10.15 Example 7 0.198 88.8 10.72 Example 8 0.204 84.9 10.77 Example 9 0.202 79.4 9.78 Comparative Example 1 0.198 73.1 8.89 Comparative Example 2 0.203 72.7 8.83 Comparative Example 3 0.198 72.0 8.85 Comparative Example 4 0.197 72.8 8.92 Comparative Example 5 0.199 71.2 8.74

[0109] (II) Barrier properties

[0110] The film was placed in a 23°C dryer and dried for 24 hours. The oxygen permeability of the film was tested at 23°C using an oxygen permeability tester. The oxygen permeability / (mL / m 2 The results are shown in Table 3.

[0111] (III) Biodegradation performance test

[0112] The film was buried in the soil for biodegradation. The biodegradation test was carried out in an incubator with relative humidity of air and soil of 60% and 80% respectively. The biodegradation temperature was maintained at 25-30°C. All film samples were buried 0.1m below the soil. The samples were recovered after 60 days. The film samples were cleaned and dried in a vacuum drying oven at 50°C for 5h. The biodegradation rate of the film was calculated as follows: (W1-W2) / W1×100%. W1 and W2 are the weights of the film before and after the soil biodegradation test, respectively. The results are shown in Table 3.

[0113] Table 3 Barrier properties and biodegradability of films

[0114]

[0115] It can be seen from Tables 2 and 3 that after camellia oil is modified by esterification with octenylsuccinic anhydride, it is combined with oxidized cellulose and sodium alginate to prepare a film. The obtained film has better mechanical properties, better oxygen barrier effect and biodegradability, and has a good application scenario in food packaging.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A modified camellia oil, characterized in that: The preparation method of the modified camellia oil comprises the following steps: (1) mixing camellia oil with sufficient methanol and catalyst 4-dimethylaminopyridine at 80-100° C. for reaction for 60-90 minutes, and then removing excess methanol to obtain transesterified camellia oil; (2) mixing the transesterified camellia oil and octenyl succinic anhydride in a reaction solvent to obtain a reaction system A, wherein the mass ratio of the transesterified camellia oil to the octenyl succinic anhydride is 1:(0.2-0.35); (3) adding triethylamine and catalyst 4-dimethylaminopyridine to reaction system A, and reacting at 90-120° C. for 60-90 minutes; the amount of triethylamine is 1%-2% of the mass of the transesterified camellia oil, and the amount of 4-dimethylaminopyridine is 0.5%-1% of the mass of the transesterified camellia oil; (4) cooling to 50-65°C and adding alkali solution to adjust the pH to 7.0-7.5; (5) Removing the reaction solvent in the system of step (4) to obtain modified camellia oil.

2. The modified camellia oil according to claim 1, characterized in that In the step (1), camellia oil is reacted with a sufficient amount of methanol in a reaction solvent, N,N-dimethylformamide, and the solvent is removed after the reaction is completed; in the step (2), the mass ratio of the transesterified camellia oil to octenyl succinic anhydride is 1:(0.25-0.35), and the reaction solvent is N,N-dimethylformamide.

3. The modified camellia oil according to claim 1, characterized in that In the step (3), the amount of triethylamine used is 1.5% to 2% of the mass of the transesterified camellia oil; the amount of 4-dimethylaminopyridine used is 0.5% to 1% of the mass of the transesterified camellia oil.

4. The modified camellia oil according to claim 1, characterized in that The method for removing the reaction solvent in the system of step (4) is: removing the reaction solvent by low-pressure evaporation at a temperature below 50°C.

5. A method for preparing modified camellia oil, characterized in that: The preparation method of the modified camellia oil comprises the following steps: (1) mixing camellia oil with sufficient methanol and catalyst 4-dimethylaminopyridine at 80-100° C. for reaction for 60-90 minutes, and then removing excess methanol to obtain transesterified camellia oil; (2) mixing the transesterified camellia oil and octenyl succinic anhydride in a reaction solvent to obtain a reaction system A; (3) adding triethylamine and catalyst 4-dimethylaminopyridine to reaction system A, and reacting at 90-120° C. for 60-90 minutes; (4) cooling to 50-65°C and adding alkali solution to adjust the pH to 7.0-7.5; (5) removing the reaction solvent in the system of step (4) to obtain modified camellia oil; In the step (2), the mass ratio of the transesterified camellia oil to octenylsuccinic anhydride is 1:(0.2-0.35), and the reaction solvent is N,N-dimethylformamide; in the step (3), the amount of triethylamine is 1%-2% of the mass of the transesterified camellia oil; the amount of 4-dimethylaminopyridine is 0.5%-1% of the mass of the transesterified camellia oil; in the step (5), the method for removing the reaction solvent in the system of step (4) is: removing the reaction solvent by low-pressure evaporation at a temperature below 50°C.

6. A film prepared using modified camellia oil, characterized in that: The method for preparing the film comprises the following steps: (I) dissolving cellulose and lithium chloride in N,N-dimethylacetamide, heating and stirring at 90-105° C. for 45-75 minutes, and then stirring at 25-30° C. for 4-8 hours to obtain a cellulose suspension; (II) adding deionized water to the cellulose suspension, stirring and filtering, washing with deionized water, drying, and mechanically crushing to obtain modified cellulose A; (III) mixing modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide in deionized water to obtain a mixed aqueous solution A; wherein the mass ratio of modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide is 1:(0.08-0.12):(0.1-0.15); (IV) mixing a sodium hypochlorite aqueous solution having a pH of 9.8 to 10.2 with the mixed aqueous solution A for reaction, adding sodium hydroxide during the reaction to adjust and maintain the pH of the reaction system at 9.8 to 10.2, and adding ethanol to terminate the reaction after the pH no longer needs sodium hydroxide adjustment, filtering and washing with water to obtain a suspension of modified cellulose B; (V) stirring the suspension of modified cellulose B, the modified camellia oil as claimed in any one of claims 1 to 4, and an aqueous solution of sodium alginate in a constant temperature water bath at 45 to 55° C. for 15 to 30 minutes until fully mixed to obtain a mixed solution B; (VI) After the mixed solution B is filtered and formed into a wet film, ion cross-linking is carried out in a calcium chloride aqueous solution with a mass concentration of 2.5% to 3.5%. After standing at 25 to 30° C. for 18 to 24 hours, the film is dried to obtain a film prepared using modified camellia oil.

7. The film prepared by using modified camellia oil according to claim 6, characterized in that: In the step (V), the amount of the suspension of modified cellulose B, the modified camellia oil as claimed in any one of claims 1 to 4, and sodium alginate is, measured on a dry basis of the suspension of modified cellulose B, 100 parts by weight of the suspension of modified cellulose B, 10 to 25 parts by weight of the modified camellia oil as claimed in any one of claims 1 to 4, and 25 to 50 parts by weight of sodium alginate, and a 1.5% to 2.5% aqueous solution of sodium alginate is mixed with the suspension of modified cellulose B and the modified camellia oil as claimed in any one of claims 1 to 4.

8. The film prepared by using modified camellia oil according to claim 6, characterized in that: In the step (I), the usage ratio of cellulose, lithium chloride and N,N-dimethylacetamide is: (2-4) g cellulose: (2-3) g lithium chloride: 100 mL N,N-dimethylacetamide.

9. The film prepared by using modified camellia oil according to claim 6, characterized in that: In the step (IV), the amount of sodium hypochlorite used is such that the weight ratio of sodium hypochlorite to modified cellulose A is (0.8-1.2):10, the mass concentration of the sodium hypochlorite aqueous solution is 10%-15%, and the pH is adjusted to 9.8-10.2 with concentrated hydrochloric acid.

10. A method for preparing a film using modified camellia oil, characterized in that: The preparation method comprises the following steps: (I) dissolving cellulose and lithium chloride in N,N-dimethylacetamide, heating and stirring at 90-105° C. for 45-75 minutes, and then stirring at 25-30° C. for 4-8 hours to obtain a cellulose suspension; (II) adding deionized water to the cellulose suspension, stirring and filtering, washing with deionized water, drying, and mechanically crushing to obtain modified cellulose A; (III) mixing modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide in deionized water to obtain a mixed aqueous solution A; wherein the mass ratio of modified cellulose A, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and sodium bromide is 1:(0.08-0.12):(0.1-0.15); (IV) mixing a sodium hypochlorite aqueous solution having a pH of 9.8 to 10.2 with the mixed aqueous solution A for reaction, adding sodium hydroxide during the reaction to adjust and maintain the pH of the reaction system at 9.8 to 10.2, and adding ethanol to terminate the reaction after the pH no longer needs sodium hydroxide adjustment, filtering and washing with water to obtain a suspension of modified cellulose B; (V) stirring the suspension of modified cellulose B, the modified camellia oil as claimed in any one of claims 1 to 4, and an aqueous solution of sodium alginate in a constant temperature water bath at 45 to 55° C. for 15 to 30 minutes until fully mixed to obtain a mixed solution B; (VI) After the mixed solution B is filtered and formed into a wet film, ion cross-linking is carried out in a calcium chloride aqueous solution with a mass concentration of 2.5% to 3.5%. After standing at 25 to 30° C. for 18 to 24 hours, the film is dried to obtain a film prepared using modified camellia oil.

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