Preparation method of oil tea steroid biodegradable film

Abstract

The invention relates to a preparation method of a camellia oleifera steroid biodegradable film. The preparation method comprises the following steps: providing a camellia oleifera steroid compound; the method comprises the following steps: catalyzing hydroxylation reaction of oil tea steroids through P450 oxygenase to obtain hydroxyl steroids; the preparation method comprises the following steps: carrying out esterification copolymerization on a steroid compound with hydroxyl and terpenoid acid saponin with carboxyl to obtain a steroid plasticizer; the degradable film is obtained by mixing a bio-based material and a steroid plasticizer, and the mass ratio of the bio-based material to the steroid plasticizer is (100: 10)-(100: 25). According to the preparation method of the oil tea steroid biodegradable film, the steroid plasticizer is provided by the tea steroid compound and the carboxyl terpenoid acidic saponin, and is added into a bio-based material as a substitute of a traditional PAEs plasticizer, so that the elasticity modulus, the elongation at break, the toughness and / or the degradability can be improved; meanwhile, the toxicity of the micro-nano plastic is reduced, and the micro-nano plastic can be applied to multiple fields.

Description

Technical Field

[0001] The present invention relates to degradable bioplastics, and more particularly to a method for preparing a camellia steroid biodegradable film. Background Art

[0002] Ubiquitous plastic pollution has posed a serious threat to global ecological and environmental security and human health. How to deal with the negative impact of plastic pollution is a major challenge facing the world. According to statistics, the current global cumulative plastic production has reached 8.3x10 9 However, only 20% of plastics are recycled, and the remaining approximately 80% ends up in the soil, rivers and marine environments.

[0003] As the global plastic pollution problem becomes increasingly serious, biodegradable plastics such as polylactic acid (PLA) and polyhydroxybutyrate (PHB) are considered to be effective alternatives to traditional plastics. However, in order to improve the performance of bioplastics, existing biodegradable plastics usually need to add plasticizers such as phthalates (PAEs), but these plasticizers easily migrate into the environment, posing potential toxic risks to the ecological environment and biological health. For example, PAEs in plastic film are the main source of PAEs in the soil of fruit and vegetable fields, and are therefore easily accumulated in the food chain. According to surveys, the PAE content in film-covered soil is 5 times that of unfilmed soil. Summary of the Invention

[0004] In order to solve the potential toxicity risk problem caused by the PAEs plasticizer in the prior art, the present invention provides a method for preparing a camellia steroid biodegradable film.

[0005] The method for preparing a camellia steroid biodegradable film according to the present invention comprises the following steps: S1, providing a camellia steroid compound; S2, catalyzing the hydroxylation reaction of the camellia steroid compound by P450 oxygenase to obtain a hydroxylated steroid compound, wherein the mass ratio of the camellia steroid compound to the P450 oxygenase is between (500-1000):(10-20); S3, esterifying and copolymerizing the hydroxylated steroid compound with a carboxyl-containing terpenoid acid saponin to obtain a steroid plasticizer; S4, obtaining a degradable film by mixing a bio-based material and the steroid plasticizer, wherein the mass ratio of the bio-based material to the steroid plasticizer is between 100:10 and 100:25.

[0006] In a preferred embodiment, in step S2, the mass ratio of camellia steroids to P450 oxygenase is between 1000:10 and 1000:15.

[0007] In a preferred embodiment, in step S2, hydroxyl groups are introduced into the camellia oleifera steroids by P450 oxygenase, and hydroxyl-bearing steroids with increased polarity are obtained by membrane separation technology.

[0008] In a preferred embodiment, in step S3, the carboxyl-containing terpenoid acidic saponin is tea saponin.

[0009] In a preferred embodiment, in step S3, the steroid compound with a hydroxyl group and the acidic saponin with a carboxyl group are polymerized in a ratio of hydroxyl group to carboxyl group of (1-3): (1-3).

[0010] In a preferred embodiment, in step S4, the bio-based material is polylactic acid and / or polyhydroxybutyrate.

[0011] In a preferred embodiment, in step S4, the bio-based material and the steroid plasticizer are stirred at a rotation speed of 1000 r / min-2000 r / min for 20 min-30 min to obtain a uniformly mixed mixture.

[0012] In a preferred embodiment, the mixture is hot-pressed in a plate vulcanizer at 110° C.-145° C. and 3 MPa-10 MPa for 5 min-30 min to obtain a transparent degradable film.

[0013] In a preferred embodiment, the preparation method further comprises performing a performance test on the degradable film.

[0014] In a preferred embodiment, the elastic modulus of the degradable film is between 3000 MPa and 4000 MPa, the elongation at break is between 4% and 10%, the tensile strength is between 50 MPa and 70 MPa, and the degradability is greater than 90%.

[0015] According to the preparation method of the tea steroid biodegradable film of the present invention, a steroid plasticizer is provided by tea steroid compounds and carboxyl terpene acid saponins, which are added to bio-based materials as a substitute for traditional PAEs plasticizers. The elastic modulus, elongation at break, toughness, and / or degradability can be improved, while the toxicity problem of micro-nano plastics is reduced. The film can be applied in multiple fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a flow chart of the method for preparing the camellia oleifera steroid biodegradable film.

[0017] Figure 2 The toxicity reduction rate of Example 1 according to the present invention is shown.

[0018] Figure 3 The toxicity reduction rate of Example 2 according to the present invention is shown. DETAILED DESCRIPTION

[0019] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0020] like Figure 1 As shown, the method for preparing a camellia steroid biodegradable film according to the present invention first involves providing a raw material of camellia steroids. Camellia steroids are spirosterane compounds composed of 27 carbon atoms, are carboxyl-free, and are neutral. They are also known as neutral camellia saponins and are found in camellia seeds or camellia cake. Camellia seeds are the seeds of the tea tree, and camellia cake is the residue left after the oil is extracted from the camellia seeds. Camellia steroids can be isolated from the camellia cake using methods such as organic solvent extraction, enzymatic extraction, or supercritical fluid extraction.

[0021] like Figure 1 As shown, the method for preparing a camellia steroid biodegradable film according to the present invention then includes catalyzing a hydroxylation reaction of camellia steroid compounds using P450 oxygenase to obtain hydroxylated steroid compounds, wherein the mass ratio of camellia steroid compounds to P450 oxygenase is between (500-1000):(10-20). Specifically, a hydroxyl group (-OH) is introduced into the camellia steroid compounds by P450 oxygenase, and the hydroxylated steroid compounds with increased polarity are obtained by membrane separation technology. P450 oxygenase (P450 Monooxygenase), also known as cytochrome P450 enzyme (Cytochrome P450), can be extracted and purified from animal and plant tissues or microorganisms, or expressed in microorganisms (such as Escherichia coli, yeast) or cell lines through genetic engineering techniques. P450 oxygenase can also be purchased directly, for example, from Shandong Kelongte Enzyme Co., Ltd. In a preferred embodiment. In a preferred embodiment, the mass ratio of camellia steroid to P450 oxygenase is between 1000:10 and 1000:15. In a preferred embodiment, the reaction mixture after the P450 oxygenase-catalyzed hydroxylation reaction comprises hydroxylated steroid, unreacted camellia steroid, P450 oxygenase, solvent, and other impurities, and the hydroxylated steroid is effectively retained and separated using a separation membrane with a pore size greater than 10 nm.

[0022] like Figure 1 As shown, the method for preparing the tea steroid biodegradable film according to the present invention then includes esterification copolymerization of a hydroxyl-containing steroid compound and a carboxyl-containing terpene acidic saponin to obtain a steroid plasticizer. The carboxyl-containing terpene acidic saponin is composed of a terpene skeleton, a carboxyl functional group, and a glycoside portion, and can be extracted from plants (such as ginseng, soybeans, etc.) using solvent extraction, enzymatic extraction, or supercritical fluid extraction. In a preferred embodiment, the carboxyl-containing terpene acidic saponin is tea saponin. In a preferred embodiment, the hydroxyl-containing steroid compound and the carboxyl-containing terpene acidic saponin are polymerized according to a hydroxyl group to carboxyl group ratio of (1-3): (1-3).

[0023] like Figure 1As shown, the preparation method of the oil-tea camellia steroid biodegradable film according to the present invention then includes obtaining a degradable film by mixing a bio-based material and a steroid plasticizer, wherein the mass ratio of the bio-based material to the steroid plasticizer is between 100:10 and 100:25. In a preferred embodiment, the bio-based material is polylactic acid (PLA) and / or polyhydroxybutyrate (PHB). In a preferred embodiment, the bio-based material is PLA and / or PHB produced by microbial fermentation. In a preferred embodiment, the bio-based material and the steroid plasticizer are stirred at a speed of 1000r / min-2000r / min for 20min-30min to obtain a uniformly mixed mixture. In a preferred embodiment, the mixture is hot pressed in a flat plate vulcanizer at 110℃-145℃ and 3MPa-10MPa for 5min-30min to obtain a transparent degradable film.

[0024] like Figure 1 As shown, the preparation method of the tea oil steroid biodegradable film according to the present invention finally includes performance testing and application of the degradable film. The elastic modulus of the degradable film according to the present invention is between 3000MPa-4000MPa, the elongation at break is between 4%-10%, the tensile strength (toughness) is between 50MPa-70MPa, and the degradability is greater than 90%. Compared with traditional biodegradable plastic films without the addition of steroid plasticizers, the elastic modulus, elongation at break and toughness of the degradable film according to the present invention are respectively increased by 30%-50%. Compared with traditional biodegradable plastic films without the addition of steroid plasticizers, the toxicity rate of the degradable film according to the present invention when it is formed into micro-nano plastics is reduced by 50%-75%. Compared with traditional biodegradable plastic films without the addition of steroid plasticizers, the degradable film according to the present invention has been verified through exposure tests to have no effect on the enzymatic activity of proteases and / or cellulases. In a preferred embodiment, the eco-matrix (T / CVA1-2024) was covered with a degradable film, and a blank test was performed in an artificial incubator at a relative humidity of 60%-65%, 20°C-25°C, and a photoperiod of 12h:12h (dark: light) for 3 days, and the enzymatic activity of the protease was not affected. In a preferred embodiment, the eco-matrix (T / CVA1-2024) was covered with a degradable film, and a blank test was performed in an artificial incubator at a relative humidity of 60%-65%, 20°C-25°C, and a photoperiod of 12h:12h (dark: light) for 3 days, and the enzymatic activity of the cellulase was not affected.

[0025] Example 1

[0026] Take 1000g of neutral saponin from camellia oleifera and add 10g of P450 oxygenase to carry out catalytic hydroxylation reaction. 100g of hydroxylated steroid compounds were obtained by membrane separation technology. The hydroxylated steroid compounds were copolymerized with tea saponin by esterification reaction. PLA and the polymer product were mixed in a weight ratio of 100:25, stirred at a speed of 1000r / min for 20 minutes, and hot pressed in a flat-plate vulcanizer at 110°C and 3MPa for 10 minutes to prepare a transparent degradable film. After testing, according to the national standard "GB / t1040.2-2016", the elastic modulus of the film is 3000MPa, the elongation at break is 4%, the tensile strength is 50MPa, and the biodegradability reaches 95%. According to GB / T41010-2021 "Degradability and Labeling Requirements of Biodegradable Plastics and Products", and referring to the test method for the toxicological effects of ingestion of different types of microplastics on juvenile barramundi, the toxicity of PLA is reduced by 50% at micro-nano size, such as Figure 2 shown.

[0027] Example 2

[0028] 1000g of neutral camellia saponins were catalyzed by the addition of 15g of P450 oxygenase for a hydroxylation reaction. 120g of hydroxylated steroids were obtained through membrane separation. The hydroxylated steroids were then copolymerized with tea saponins through an esterification reaction. PHB and the polymer product were mixed at a weight ratio of 100:10 at 2000 rpm for 30 minutes, and then hot-pressed in a plate-type vulcanizer at 120°C and 5 MPa for 10 minutes to produce a transparent biodegradable film. Testing revealed that according to the national standard GB / T 1040.2-2016, the film exhibited an elastic modulus of 4000 MPa, an elongation at break of 10%, and a tensile strength of 70 MPa, achieving a biodegradability of 92%. Furthermore, according to GB / T 41010-2021, "Degradability and Labeling Requirements for Biodegradable Plastics and Products," and in accordance with the test method for the toxicological effects of different microplastics on juvenile barramundi, the toxicity of PHB at micro- and nanoscale sizes was reduced by 70%.

[0029] Example 3

[0030] 1000g of neutral camellia saponin was taken, and 15g of P450 oxygenase was added to carry out a catalytic hydroxylation reaction. 120g of hydroxylated steroid compounds were obtained through membrane separation technology. The hydroxylated steroid compounds were then copolymerized with tea saponin through an esterification reaction. PLA and the polymer product were mixed at a weight ratio of 100:25 at a speed of 2000 r / min for 30 minutes, and then hot-pressed in a flat-plate vulcanizer at 120°C and 5MPa for 10 minutes to prepare a transparent biodegradable film. This film was then covered on an ecological substrate (T / CVA1-2024) for exposure testing. A comparative blank test was conducted in an artificial incubator at 60% relative humidity, 20°C, and a 12h:12h (dark:light) photoperiod for 3 days. The results showed that the film had no significant effect on protease activity, that is, it did not affect the degradation performance after application.

[0031] Example 4

[0032] 1000g of neutral camellia saponins were catalyzed and hydroxylated by the addition of 15g of P450 oxygenase. 120g of hydroxylated steroids were obtained by membrane separation. The hydroxylated steroids were then copolymerized with tea saponin via esterification. PHB and the polymer product were mixed at a weight ratio of 100:10 at 2000 rpm for 30 minutes, and then hot-pressed in a flat-plate vulcanizer at 120°C and 5 MPa for 10 minutes to prepare a transparent, biodegradable film. This film was then applied to an ecological substrate (T / CVA1-2024) for exposure testing, compared to a blank test, conducted in an artificial incubator at 65% relative humidity, 25°C, and a 12h:12h (dark:light) photoperiod for 3 days. The results showed that the film had no significant effect on cellulase activity, indicating no impact on degradation performance after application.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible. In other words, any simple, equivalent changes and modifications made in accordance with the claims and description of the present invention are within the scope of protection of the patent claims. Anything not fully described in this invention constitutes conventional technology.

Claims

1. A method for preparing a camellia oleifera steroid biodegradable film, characterized in that: The preparation method comprises the following steps: S1, providing camellia steroids; S2, catalyzing the hydroxylation reaction of the camellia steroid compound by P450 oxygenase to obtain a hydroxylated steroid compound, wherein the mass ratio of the camellia steroid compound to the P450 oxygenase is between (500-1000): (10-20); S3, esterification copolymerization of hydroxyl steroid compounds and carboxyl terpenoid acid saponins to obtain steroid plasticizers; S4, obtaining a degradable film by mixing a bio-based material and a steroid plasticizer, wherein a mass ratio of the bio-based material to the steroid plasticizer is between 100:10 and 100:

25.

2. The preparation method according to claim 1, characterized in that In step S2, the mass ratio of the camellia steroid compound to the P450 oxygenase is between 1000:10 and 1000:

15.

3. The preparation method according to claim 1, characterized in that In step S2, hydroxyl groups are introduced into the camellia oleifera steroids by P450 oxygenase, and hydroxyl-containing steroids with increased polarity are obtained by membrane separation technology.

4. The preparation method according to claim 1, characterized in that In step S3, the carboxyl-containing terpenoid acidic saponin is tea saponin.

5. The preparation method according to claim 1, characterized in that In step S3, the steroid compound with a hydroxyl group and the acidic saponin with a carboxyl group are polymerized according to a group ratio of hydroxyl group to carboxyl group of (1-3): (1-3).

6. The preparation method according to claim 1, characterized in that In step S4, the bio-based material is polylactic acid and / or polyhydroxybutyrate.

7. The preparation method according to claim 1, characterized in that In step S4, the bio-based material and the steroid plasticizer are stirred at a rotation speed of 1000 r / min-2000 r / min for 20 min-30 min to obtain a uniformly mixed mixture.

8. The preparation method according to claim 7, characterized in that The mixture is hot-pressed in a flat plate vulcanizer at 110° C.-145° C. and 3 MPa-10 MPa for 5 min-30 min to obtain a transparent degradable film.

9. The preparation method according to claim 1, characterized in that The preparation method also includes performing performance testing on the degradable film.

10. The preparation method according to claim 9, characterized in that The elastic modulus of the degradable film is between 3000MPa-4000MPa, the elongation at break is between 4%-10%, the tensile strength is between 50MPa-70MPa, and the degradability is greater than 90%.

Images