High-stability plant essential oil composition, preparation and application thereof

Abstract

The application belongs to the technical fields of polymer materials and cosmetics, and discloses a high-stability plant essential oil composition and preparation and application thereof. 12 The preparation method of the plant essential oil composition comprises the following steps: adding an acrylate monomer, 1-vinyl-2-pyrrolidone and C6-C 12 The diene crosslinking agent is added into an organic solvent for mixing and dissolving, and then an initiator is added for copolymerization and crosslinking reaction; after the reaction is completed, the solvent is removed by rotary evaporation to obtain an acrylate / VP crosslinking copolymer; then the obtained acrylate / VP crosslinking copolymer is added into mixed oil of plant essential oil and plant oil for mixing and swelling to obtain the high-stability plant essential oil composition. The specific acrylate / VP crosslinking copolymer is used for gel-state wrapping protection of the plant essential oil, and the application efficacy stability of the plant essential oil in a skin care product formula can be significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials and cosmetics technology, specifically relating to a highly stable plant essential oil composition and its preparation and application. Background Technology

[0002] Plant essential oils are highly active and volatile components extracted from the flowers, leaves, roots, bark, fruits, seeds, and resins of herbaceous plants through distillation and pressing. Some plant essential oils are widely used in cosmetics due to their excellent anti-aging and repairing effects. For example, patent documents CN 108778241 B and CN 111886052 B both describe the use of cosmetic compositions containing helichrysum essential oil in combating signs of skin aging and / or dry skin. Patent documents CN108836897A and CN103361181A both describe cosmetics containing rose essential oil that have excellent nourishing, skin-protecting, whitening, anti-aging, anti-wrinkle, and antibacterial effects on the skin.

[0003] However, due to the generally poor volatility and water solubility of plant essential oils, their efficacy stability in water-based skincare formulations is relatively poor. While emulsifiers can improve the dispersion stability of plant essential oils, they cannot effectively protect the active components. Encapsulation with polymers is an effective method to improve the stability of plant essential oil application effects. For example, patent document CN 118384056 B describes the use of multi-layer nanocomposite emulsions to protect plant essential oils, reduce their volatility, and control their release rate, producing a sustained-release effect. However, the preparation method of this multi-layer nanocomposite emulsion is relatively complex, requiring the sequential emulsification and encapsulation of collagen, chitosan, natural plant oils, and natural plant waxes, which have poor compatibility, making process control difficult.

[0004] Therefore, providing a highly stable plant essential oil composition with a simple preparation process and good encapsulation effect, and its application in cosmetics, has significant practical implications. Summary of the Invention

[0005] To improve the stability of plant essential oils in water-based skincare product formulations, the primary objective of this invention is to provide a method for preparing a highly stable plant essential oil composition.

[0006] Another object of the present invention is to provide a highly stable plant essential oil composition prepared by the above method.

[0007] Another object of the present invention is to provide the application of the above-mentioned highly stable plant essential oil composition in cosmetics.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A method for preparing a highly stable plant essential oil composition includes the following preparation steps:

[0010] (1) Acrylate monomer, 1-vinyl-2-pyrrolidone (VP) and C6-C 12 The diene crosslinking agent is added to an organic solvent and mixed and dissolved. Then, an initiator is added to carry out a copolymerization and crosslinking reaction. After the reaction is completed, the solvent is removed by rotary evaporation to obtain an acrylate / VP crosslinked copolymer.

[0011] (2) The obtained acrylate / VP crosslinked copolymer was added to a mixture of plant essential oil and vegetable oil and mixed and swollen to obtain a highly stable plant essential oil composition.

[0012] Furthermore, the acrylate monomer is one or more of ethyl acrylate, butyl acrylate, and isooctyl acrylate.

[0013] The use of acrylate monomers in this invention is mainly to improve compatibility with oily components and enhance the swelling and encapsulation effect.

[0014] Furthermore, the mass of the added 1-vinyl-2-pyrrolidone is 15-40% of the mass of the acrylate monomer.

[0015] This invention utilizes 1-vinyl-2-pyrrolidone monomer copolymerization, which simultaneously enhances the lipophilicity and hydrophilicity of the crosslinked copolymer. On one hand, it improves the swelling effect of plant essential oils and plant oils (the pyrrolidone structure exhibits good compatibility with small-molecule esters, ketones, and alcohols in plant essential oils). On the other hand, it improves the emulsifying performance in aqueous skincare formulations. If the amount of 1-vinyl-2-pyrrolidone added is too low, the emulsifying performance of the resulting gel composition decreases; if the amount added is too high, the plant essential oils are easily leached out by the aqueous phase, reducing the protective effect of encapsulating the plant essential oils.

[0016] Furthermore, the C6-C 12 The diene crosslinking agent is one or more of 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, and 1,11-dodecadiene.

[0017] Furthermore, the C6-C 12 The mass of the diene crosslinking agent added is 0.5% to 5% of the mass of the acrylate monomer.

[0018] This invention uses C6-C 12Diene crosslinking agents can form a hydrophobic and lipophilic three-dimensional crosslinked network, making this network more easily swollen by oily plant essential oils and plant oils, but difficult to swell by water. This achieves gel-like encapsulation and protection of plant essential oils, and makes them less likely to be leached out by the aqueous phase when used in subsequent water-based skincare formulations, thus improving the encapsulation stability of plant essential oils.

[0019] Furthermore, the organic solvent is one or more of ethyl acetate, cyclohexane, and acetone.

[0020] Furthermore, the initiator is benzoyl peroxide (BPO) or azobisisobutyronitrile (AIBN); the temperature of the copolymerization crosslinking reaction is 60-70°C, and the time is 2-4 hours.

[0021] Furthermore, the plant essential oil is one or more of helichrysum essential oil, rose essential oil, and lavender essential oil.

[0022] Furthermore, the vegetable oil is one or more of jojoba oil, olive oil, argan oil, grapeseed oil, sweet almond oil, and camellia seed oil.

[0023] Furthermore, in the mixed oil, the mass ratio of plant essential oil to plant oil is 2 to 5:1.

[0024] This invention reduces the volatility of plant essential oils by compounding them with plant oils. However, an excessively high proportion of plant oils can lead to a reduced swelling and encapsulation effect.

[0025] Furthermore, the amount of the acrylate / VP crosslinked copolymer added is 0.5-10% of the mass of the mixed oil.

[0026] A highly stable plant essential oil composition was prepared by the above method.

[0027] Application of the above-mentioned highly stable plant essential oil composition in cosmetics.

[0028] Furthermore, the application method is as follows: the highly stable plant essential oil composition is added to an aqueous cosmetic formula containing emulsifier and moisturizer at a mass percentage of 0.1-5%, and homogenized and emulsified until uniform, to obtain the finished product.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] (1) The present invention uses a specific acrylate / VP cross-linked copolymer to encapsulate and protect plant essential oils in a gel state, which can significantly improve the stability of their application efficacy in skin care product formulations.

[0031] (2) The preparation process of the acrylate / VP crosslinked copolymer of the present invention is simple. The obtained acrylate / VP crosslinked copolymer is easily encapsulated by plant essential oils and is not easily leached out by the aqueous phase, thus having a good encapsulation effect on plant essential oils. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0033] Example 1

[0034] A method for preparing a highly stable plant essential oil composition includes the following preparation steps:

[0035] (1) Ethyl acrylate, 1-vinyl-2-pyrrolidone and 1,6-heptadiene crosslinking agent were added to a mixed solvent of ethyl acetate and acetone with a volume ratio of 2:1 at a mass ratio of 100:25:2.5 and stirred to dissolve. After deoxygenation by nitrogen, the temperature was raised to 65°C. Then, AIBN initiator was added and the temperature was maintained for copolymerization and crosslinking reaction for 3 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a white powder acrylate / VP crosslinking copolymer.

[0036] (2) The obtained acrylate / VP cross-linked copolymer was added to a mixture of hemerocallis essential oil and jojoba oil with a mass ratio of 3.5:1 and mixed and swollen. The amount of acrylate / VP cross-linked copolymer added was 5% of the mass of the mixed oil. The mixture was stirred and swollen at room temperature for 8 hours to obtain a transparent gel-like high-stability plant essential oil composition.

[0037] Example 2

[0038] A method for preparing a highly stable plant essential oil composition includes the following preparation steps:

[0039] (1) Butyl acrylate, 1-vinyl-2-pyrrolidone and 1,8-nonadiene crosslinking agent were added to a mixed solvent of ethyl acetate and acetone with a volume ratio of 2:1 at a mass ratio of 100:20:3.5 and stirred to dissolve. After deoxygenation by nitrogen, the temperature was raised to 65°C, and then AIBN initiator was added and kept warm for copolymerization and crosslinking reaction for 3.5 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a white powder acrylate / VP crosslinking copolymer.

[0040] (2) The obtained acrylate / VP cross-linked copolymer was added to a mixture of hemerocallis essential oil and olive oil in a mass ratio of 4:1 and mixed and swollen. The amount of acrylate / VP cross-linked copolymer added was 3% of the mass of the mixture. The mixture was stirred and swollen at room temperature for 6 hours to obtain a transparent gel-like high-stability plant essential oil composition.

[0041] Example 3

[0042] A method for preparing a highly stable plant essential oil composition includes the following preparation steps:

[0043] (1) Isooctyl acrylate, 1-vinyl-2-pyrrolidone and 1,11-dodecadiene crosslinking agent were added to a mixed solvent of ethyl acetate and acetone with a volume ratio of 2:1 at a mass ratio of 100:30:5 and stirred to dissolve. After deoxygenation by nitrogen, the temperature was raised to 70°C. Then AIBN initiator was added and kept warm for 4 hours for copolymerization and crosslinking reaction. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a white powder acrylate / VP crosslinking copolymer.

[0044] (2) The obtained acrylate / VP cross-linked copolymer was added to a mixture of hemerocallis essential oil and argan oil in a mass ratio of 5:1 and mixed and swollen. The amount of acrylate / VP cross-linked copolymer added was 7% of the mass of the mixture. The mixture was stirred and swollen at room temperature for 8 hours to obtain a transparent gel-like high-stability plant essential oil composition.

[0045] Example 4

[0046] A method for preparing a highly stable plant essential oil composition includes the following preparation steps:

[0047] (1) Butyl acrylate, 1-vinyl-2-pyrrolidone and 1,7-octadiene crosslinking agent were added to a mixed solvent of ethyl acetate and acetone with a volume ratio of 2:1 at a mass ratio of 100:40:4 and stirred to dissolve. After deoxygenation by nitrogen, the temperature was raised to 60°C. Then, AIBN initiator was added and kept warm for 3 hours for copolymerization and crosslinking reaction. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a white powder acrylate / VP crosslinking copolymer.

[0048] (2) The obtained acrylate / VP cross-linked copolymer was added to a mixture of rose essential oil and camellia seed oil in a mass ratio of 3:1 and mixed and swollen. The amount of acrylate / VP cross-linked copolymer added was 1% of the mass of the mixed oil. The mixture was stirred and swollen at room temperature for 5 hours to obtain a transparent gel-like high-stability plant essential oil composition.

[0049] Example 5

[0050] A method for preparing a highly stable plant essential oil composition includes the following preparation steps:

[0051] (1) Ethyl acrylate, 1-vinyl-2-pyrrolidone and 1,9-decadiene crosslinking agent were added to a mixed solvent of ethyl acetate and acetone with a volume ratio of 2:1 at a mass ratio of 100:15:1 and stirred to dissolve. After deoxygenation by nitrogen, the temperature was raised to 60°C. Then, AIBN initiator was added and the temperature was maintained for copolymerization and crosslinking reaction for 2 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a white powder acrylate / VP crosslinking copolymer.

[0052] (2) The obtained acrylate / VP cross-linked copolymer was added to a mixture of lavender essential oil and sweet almond oil in a mass ratio of 2:1 and mixed and swollen. The amount of acrylate / VP cross-linked copolymer added was 0.5% of the mass of the mixed oil. The mixture was stirred and swollen at room temperature for 4 hours to obtain a transparent gel-like high-stability plant essential oil composition.

[0053] Comparative Example 1

[0054] Helichrysum essential oil and jojoba oil were mixed evenly at a mass ratio of 3.5:1 to obtain a transparent plant essential oil composition.

[0055] Comparative Example 2

[0056] (1) Ethyl acrylate and 1-vinyl-2-pyrrolidone were added to a mixed solvent of ethyl acetate and acetone in a volume ratio of 2:1 at a mass ratio of 100:25 and stirred to dissolve. After deoxygenation by nitrogen, the temperature was raised to 65°C. Then, AIBN initiator was added and kept warm for copolymerization and crosslinking reaction for 3 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a white powder acrylate / VP copolymer.

[0057] (2) The obtained acrylic acid / VP copolymer was added to a mixture of hemerocallis essential oil and jojoba oil in a mass ratio of 3.5:1 and mixed and swollen. The amount of acrylic acid / VP copolymer added was 5% of the mass of the mixed oil. The mixture was stirred and swollen at room temperature for 8 hours to obtain a transparent and viscous plant essential oil composition.

[0058] Comparative Example 3

[0059] Ethyl acrylate, 1-vinyl-2-pyrrolidone, and pentaerythritol triallyl ether crosslinking agent were added to a mixed solvent of ethyl acetate and acetone in a mass ratio of 100:25:2.5 and stirred to dissolve. After deoxygenation with nitrogen, the mixture was heated to 65°C, and then AIBN initiator was added and kept at the temperature for copolymerization and crosslinking reaction for 3 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a white powdery acrylate / VP crosslinked copolymer.

[0060] The acrylate / VP crosslinked copolymer obtained in this comparative example failed to swell when added to a mixture of hemerocallis essential oil and jojoba oil at a mass ratio of 3.5:1, resulting in a transparent gel-like composition. This indicates that the present invention utilizes C6-C... 12 Diene crosslinking agents are crucial for achieving the swelling and encapsulation of plant essential oils.

[0061] The application performance of the obtained plant essential oil composition was tested:

[0062] The application formula is: PPG-5-laureyl polyether-5 6%, glycerin 6%, 1,3-butanediol 4%, jojoba oil 3%, plant essential oil composition 2.5%, and deionized water 78.5%.

[0063] The test sample was prepared as follows: PPG-5-lauryl ether-5, 6% glycerol and 1,3-butanediol were added to deionized water and stirred to dissolve. Then, jojoba oil and a plant essential oil composition were added and homogenized and emulsified by a high-pressure homogenizer to obtain a plant essential oil anti-aging repair emulsion.

[0064] The application performance testing method was as follows: The plant essential oil compositions of Example 1, Comparative Example 1, and Comparative Example 2 were prepared into test samples according to the above method, and then subjected to accelerated testing (40±2℃ / 75%±5%RH, 3 months). The samples after accelerated testing were then subjected to anti-aging and repair efficacy tests (using the MTT assay to promote the proliferation of human skin fibroblasts, calculating the proliferation rate) and soothing efficacy tests (using the hyaluronidase inhibition assay, calculating the hyaluronidase inhibition rate). The number of parallel tests was n=3, and the results were averaged. The test results are shown in the table below:

[0065] Table 1. Application performance test results of the plant essential oil compositions prepared in Examples 1 and Comparative Examples 1-2

[0066] Example 1 Comparative Example 1 Comparative Example 2 Proliferation rate (%) 108.65 71.82 80.47 Hyaluronidase inhibition rate (%) 36.77 24.15 28.50

[0067] The results above show that the present invention uses a specific acrylate / VP cross-linked copolymer to encapsulate and protect plant essential oils in a gel state, which can significantly improve the anti-aging, repairing, and soothing effects of plant essential oils in formulation applications.

[0068] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a highly stable plant essential oil composition, characterized in that: The preparation steps include the following: (1) Acrylate monomer, 1-vinyl-2-pyrrolidone and C6-C 12 The diene crosslinking agent is added to an organic solvent and mixed and dissolved. Then, an initiator is added to carry out a copolymerization and crosslinking reaction. After the reaction is completed, the solvent is removed by rotary evaporation to obtain an acrylate / VP crosslinked copolymer. (2) The obtained acrylate / VP cross-linked copolymer is added to a mixture of plant essential oil and vegetable oil and mixed and swollen to obtain a highly stable plant essential oil composition.

2. The method for preparing a highly stable plant essential oil composition according to claim 1, characterized in that: The acrylate monomer is one or more of ethyl acrylate, butyl acrylate, and isooctyl acrylate.

3. The method for preparing a highly stable plant essential oil composition according to claim 1, characterized in that: The mass of 1-vinyl-2-pyrrolidone added is 15-40% of the mass of the acrylate monomer.

4. The method for preparing a highly stable plant essential oil composition according to claim 1, characterized in that: The C6-C 12 The diene crosslinking agent is one or more of 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, and 1,11-dodecadiene, wherein the C6-C 12 The mass of the diene crosslinking agent added is 0.5 to 5% of the mass of the acrylate monomer.

5. The method for preparing a highly stable plant essential oil composition according to claim 1, characterized in that: The organic solvent is one or more of ethyl acetate, cyclohexane, and acetone; the initiator is BPO or AIBN; the temperature of the copolymerization crosslinking reaction is 60~70℃, and the time is 2~4h.

6. The method for preparing a highly stable plant essential oil composition according to claim 1, characterized in that: The plant essential oil is one or more of helichrysum essential oil, rose essential oil, and lavender essential oil; the plant oil is one or more of jojoba oil, olive oil, argan oil, grapeseed oil, sweet almond oil, and camellia seed oil; in the mixed oil, the mass ratio of plant essential oil to plant oil is 2 to 5:

1.

7. The method for preparing a highly stable plant essential oil composition according to claim 1, characterized in that: The amount of the acrylate / VP crosslinked copolymer added is 0.5-10% of the mass of the mixed oil.

8. A highly stable plant essential oil composition, characterized in that: It is prepared by the method described in any one of claims 1 to 7.

9. The use of the highly stable plant essential oil composition according to claim 8 in the preparation of cosmetics.

10. The application according to claim 9, characterized in that: The application method is as follows: the highly stable plant essential oil composition is added to an aqueous cosmetic formula containing emulsifier and moisturizer at a mass percentage of 0.1-5% and homogenized and emulsified to obtain the finished product.