Mildew-proof tablet containing plant essential oil as well as preparation method and application of mildew-proof tablet

Abstract

The invention relates to the field of essential oil slow release, and discloses a mildew-proof tablet containing plant essential oil and a preparation method and application thereof.The mildew-proof tablet containing the plant essential oil comprises two epidermal layers and an essential oil slow-release layer arranged between the two epidermal layers, the preparation method comprises the following steps: grafting sodium abietate and aminated mesoporous silica to prepare functionalized mesoporous silica, loading plant essential oil on the functionalized mesoporous silica to obtain a core material, introducing dihydroxyl polyhedral oligomeric silsesquioxane into a polyurethane main chain, wrapping the core material to prepare an essential oil slow-release agent, taking lignin as a base material, taking the essential oil slow-release agent as an effective component, and preparing the essential oil slow-release agent. And preparing to obtain the essential oil slow-release layer. The prepared essential oil slow-release layer can achieve the effects of essential oil slow release and antibiosis and mildew prevention, the slow-release effect is remarkable under the normal-temperature and high-temperature conditions, the good slow-release effect is still kept in the humid environment, and the efficacy period of the material is greatly prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of essential oil sustained release, and in particular relates to an anti-mildew sheet containing plant essential oil and a preparation method and application thereof. Background Art

[0002] Flavors and fragrances are important industrial raw materials for various flavoring products and are widely used in food, beverages, daily chemical products and other industries. Essential oils are widely used as an important component of natural flavors and fragrances, but their application is limited due to their poor stability. Microencapsulation of essential oils is a common means to solve the above problems. Nano-microcapsule technology is a technology that uses natural or synthetic polymers to encapsulate target substances in materials with a particle size of 1nm to 100nm, mainly through nano-composite materials, nano-emulsification, nano-structure technology, etc. to encapsulate micro-substances. The use of nano-microcapsule technology can effectively improve the antioxidant capacity, thermal stability and biological activity of the encapsulated object.

[0003] As the use time of essential oils increases, the effective ingredients of the essential oils decrease rapidly. Although natural plant essential oils have a certain inhibitory effect on bacteria and fungi, their long-lasting antibacterial and mildew-proof effects are poor. In addition, the wall materials used in existing microcapsule technology are highly hydrophilic and absorb water in a humid environment to form a hydration layer, which reduces the long-term sustained-release effect of the material. Summary of the invention

[0004] In order to solve the deficiencies mentioned in the above background technology, the object of the present invention is to provide a mildew-proof sheet containing plant essential oil and its preparation method and application, sodium rosin acid and amino mesoporous silica are used to graft functionalized mesoporous silica, and it is loaded with plant essential oil as a core material, dihydroxy cage silsesquioxane is introduced into the polyurethane main chain and the core material is wrapped to make an essential oil sustained-release agent, and then lignin is used as a substrate, and the essential oil sustained-release agent is used as an effective ingredient to prepare an essential oil sustained-release layer. The essential oil sustained-release agent prepared by the present invention can achieve the effects of essential oil sustained-release and antibacterial and mildew-proof, and still maintains a good sustained-release effect in a humid environment, greatly extending the efficacy period of the material.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A mildew-proof sheet containing plant essential oil comprises two epidermal layers and an essential oil sustained-release layer arranged between the two epidermal layers. The preparation method of the essential oil sustained-release layer comprises the following steps:

[0007] A1: immersing lignin in a solution containing an essential oil sustained-release agent, taking it out, and preparing essential oil-modified lignin;

[0008] A2: preparing essential oil slow-release layer by modifying lignin with essential oil;

[0009] The essential oil sustained-release agent is prepared by using functionalized mesoporous silica loaded with plant essential oil as a core material, introducing dihydroxy cage-type silsesquioxane into the main chain of polyurethane and then wrapping the core material, wherein the functionalized mesoporous silica is prepared by grafting sodium rosin acid with amino mesoporous silica by chemical reaction.

[0010] Preferably, the epidermis layer is a breathable membrane; and the solution is ethanol, deionized water, or a combination of both.

[0011] Preferably, the preparation method of the essential oil sustained-release agent comprises the following steps:

[0012] (1) Ammonia water, deionized water and hexadecyltrimethylammonium bromide are placed in a reactor, stirred at 50-65° C. and 200-300 r / min for 2-3 h, and then tetraethyl orthosilicate is added and stirred for 1-3 h. After stirring, 3-aminopropyltriethoxysilane is added dropwise and mixed for 6-8 h. The mixture is placed at 30-35° C. for crystallization at a constant temperature for 20-24 h. The template is removed by filtering, washing, drying and ethanol extraction to prepare amino mesoporous silica.

[0013] (2) dissolving sodium rosin acid in a hydrochloric acid aqueous solution to adjust the pH value of the system to 5.5-6, adding 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide and stirring and mixing for 20-24 hours, then adding amino mesoporous silica and continuing to stir and react for 18-24 hours. After the reaction is completed, filtering and drying are performed to prepare functionalized mesoporous silica;

[0014] (3) mixing the functionalized mesoporous silica with plant essential oil and subjecting the mixture to ultrasonic treatment, filtering and drying to prepare supported mesoporous silica;

[0015] (4) Polyvinyl pyrrolidone is dissolved in deionized water at 80 to 90° C., cooled to room temperature, Tween 80 is added and stirred for emulsification, and then supported mesoporous silica is added and stirred for dispersion, and then isophorone diisocyanate, 1,4-butanediol, dihydroxy cage silsesquioxane, polypropylene glycol 2000 and triethylenediamine are added, and the temperature is raised to 65 to 80° C. for reaction for 1 to 3 hours. After the reaction is completed, the essential oil sustained-release agent is prepared by suction filtration, washing and drying.

[0016] Preferably, the mass fraction of ammonia water in step (1) is 20-30%, and the addition ratio of ammonia water, deionized water, hexadecyltrimethylammonium bromide, tetraethyl orthosilicate and 3-aminopropyltriethoxysilane is 150-200 mL: 200-300 mL: 2-3.2 g: 10-15.5 g: 3.6-5 g.

[0017] Preferably, in step (2), the mass ratio of sodium rosinate to amino-modified mesoporous silica is 7.5-10:0.5.

[0018] Preferably, the plant essential oil in step (3) is one or more combinations of tea tree essential oil, mustard essential oil, cinnamon essential oil, garlic essential oil, citronella essential oil, rose essential oil, wormwood essential oil, peppermint essential oil, lemon essential oil, clove essential oil, and lavender essential oil.

[0019] Preferably, in the step (4), the mass ratio of polyvinyl pyrrolidone, Tween 80, supported mesoporous silica, isophorone diisocyanate, 1,4-butanediol, dihydroxy cage silsesquioxane, polypropylene glycol 2000 and triethylenediamine is 2.5-3: 2.5-3: 2.5-5: 8-9.6: 0.4-0.7: 0.2-0.6: 7-10: 0.02-0.06.

[0020] Preferably, the method for preparing dihydroxy cage silsesquioxane in step (4) comprises the following steps:

[0021] ① Dissolve sodium hydroxide in deionized water, add isopropanol solvent, then add phenyltrimethoxysilane and stir to mix, place under nitrogen atmosphere at 80-95° C. for reflux reaction for 3-5 hours, then cool to room temperature, continue stirring to react for 10-15 hours, and after the reaction is completed, perform rotary evaporation and drying to obtain a primary product;

[0022] ② Take the initial product, add tetrahydrofuran solvent and triethylamine, add methyltrichlorosilane in a nitrogen atmosphere, stir and react for 8 to 12 hours, then place it in an ice water bath and add deionized water to dissolve excess methyltrichlorosilane and by-products. After the reaction is completed, add toluene to extract and separate the organic layer, wash, filter, rotary evaporate and dry to prepare dihydroxy cage-type silsesquioxane.

[0023] A method for preparing an anti-mildew sheet containing plant essential oil comprises the following steps: arranging an essential oil slow-release layer between two epidermis layers and performing composite pressing to prepare the sheet.

[0024] An application of an anti-mildew sheet containing plant essential oil, characterized in that the anti-mildew sheet containing plant essential oil is used for food preservation, and anti-mildew of shoes, clothing, bags, and sofa products.

[0025] Beneficial effects of the present invention:

[0026] The present invention uses plant essential oil as an effective ingredient, loads the plant essential oil on a functionalized mesoporous silica carrier to obtain a loaded mesoporous silica, and uses the loaded mesoporous silica as a core material, introduces dihydroxy cage-type silsesquioxane into a polyurethane main chain, and then wraps the loaded mesoporous silica to prepare an essential oil sustained-release agent, and uses lignin as a substrate and the essential oil sustained-release agent as an effective ingredient to prepare an essential oil sustained-release layer. The essential oil sustained-release layer prepared by the present invention can achieve the effects of essential oil sustained-release and antibacterial and mildew-proofing, and still maintains a good sustained-release effect in a humid environment, greatly extending the efficacy period of the material.

[0027] The invention uses sodium rosin acid and amino mesoporous silica to undergo an amidation reaction to obtain functionalized mesoporous silica, and uses the functionalized mesoporous silica as a carrier to load plant essential oil. The specific surface area and pore volume of the mesoporous silica are reduced by grafting of sodium rosin acid, thereby inhibiting the volatilization of the plant essential oil and prolonging the sustained-release time of the plant essential oil. In addition, the invention prepares dihydroxy cage-type silsesquioxane, and introduces the dihydroxy cage-type silsesquioxane as a chain extender into a polyurethane main chain to modify the polyurethane. The modified polyurethane is used as a wall material of the loaded mesoporous silica, and the wall material is endowed with excellent heat resistance and hydrophobicity, and the sustained-release effect is significant under normal temperature and high temperature conditions, thereby further improving the long-term sustained-release antibacterial and mildew-proof effect of the plant essential oil. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1 A method for preparing a dihydroxy cage-type silsesquioxane comprises the following steps:

[0030] ① Take 3.2g of sodium hydroxide and dissolve it in 2.5mL of deionized water, add 120mL of isopropanol solvent, then add 24g of phenyltrimethoxysilane and stir to mix, place it under nitrogen atmosphere at 90°C for reflux reaction for 4h, then cool to room temperature, continue stirring and reacting for 12h, and after the reaction is completed, rotary evaporate and dry to prepare the primary product;

[0031] ② Take 5 g of the initial product, add 50 mL of tetrahydrofuran solvent and 1.1 g of triethylamine, add 2.7 g of methyltrichlorosilane in a nitrogen atmosphere, stir and react for 12 hours, then place it in an ice water bath, add 20 mL of deionized water to dissolve excess methyltrichlorosilane and by-products, and after the reaction is completed, add 80 mL of toluene to extract and separate the organic layer, wash, filter, rotary evaporate, and dry to prepare dihydroxy cage-type silsesquioxane.

[0032] Embodiment 2 A method for preparing an essential oil sustained-release agent comprises the following steps:

[0033] (1) 185 mL of 25% ammonia water, 250 mL of deionized water and 2.7 g of hexadecyltrimethylammonium bromide were placed in a reactor, stirred at 55° C. and 260 r / min for 2 h, and then 13.4 g of tetraethyl orthosilicate was added and stirred for 2 h. After stirring, 4.5 g of 3-aminopropyltriethoxysilane was added dropwise and mixed for 8 h. The mixture was placed at 35° C. for crystallization for 24 h. The template was removed by filtration, washing, drying and ethanol extraction to prepare amino mesoporous silica.

[0034] (2) 9.3 g of sodium rosinate was dissolved in 100 mL of hydrochloric acid solution to adjust the pH value of the system to 5.5, 1.1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.5 g of N-hydroxysuccinimide were added and stirred for 24 h, and then 0.5 g of amino-modified mesoporous silica was added and stirred for 24 h. After the reaction was completed, the functionalized mesoporous silica was filtered and dried to prepare the functionalized mesoporous silica.

[0035] (3) 1.7 g of functionalized mesoporous silica was mixed with 2 mL of mustard essential oil and subjected to ultrasonic treatment, and then filtered and dried to prepare supported mesoporous silica;

[0036] (4) Take 2.7 g of polyvinyl pyrrolidone and add it to deionized water at 85° C. to dissolve it. After cooling to room temperature, add 2.5 g of Tween 80 and stir to emulsify it. Then add 2.5 g of supported mesoporous silica and stir to disperse it. Then add 8.2 g of isophorone diisocyanate, 0.45 g of 1,4-butanediol, 0.2 g of the dihydroxy cage-type silsesquioxane prepared in Example 1, 7.1 g of polypropylene glycol 2000 and 0.02 g of triethylenediamine. The temperature is raised to 80° C. to react for 3 h. After the reaction is completed, the mixture is filtered, washed and dried to prepare an essential oil sustained-release agent.

[0037] Embodiment 3 A method for preparing an essential oil sustained-release agent comprises the following steps:

[0038] (1) 175 mL of 30% ammonia water, 270 mL of deionized water and 2.5 g of hexadecyltrimethylammonium bromide were placed in a reactor, stirred at 55° C. and 245 r / min for 2 h, and then 11.8 g of tetraethyl orthosilicate was added and stirred for 2 h. After the stirring was completed, 4.2 g of 3-aminopropyltriethoxysilane was added dropwise and mixed for 8 h. The mixture was placed at 35° C. for crystallization for 24 h, and the template was removed by filtration, washing, drying and ethanol extraction to prepare amino mesoporous silica;

[0039] (2) 7.8 g of sodium rosinate was dissolved in 100 mL of hydrochloric acid solution to adjust the pH value of the system to 6, 1.1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.6 g of N-hydroxysuccinimide were added and stirred for 24 h, and then 0.5 g of amino-modified mesoporous silica was added and stirred for 24 h. After the reaction was completed, the functionalized mesoporous silica was filtered and dried to prepare the functionalized mesoporous silica.

[0040] (3) 1.7 g of functionalized mesoporous silica was mixed with 2 mL of mustard essential oil and subjected to ultrasonic treatment, and then filtered and dried to prepare supported mesoporous silica;

[0041] (4) Take 2.5 g of polyvinyl pyrrolidone and add it to deionized water at 85° C. to dissolve it. After cooling to room temperature, add 2.7 g of Tween 80 and stir to emulsify it. Then add 3.6 g of supported mesoporous silica and stir to disperse it. Then add 8.9 g of isophorone diisocyanate, 0.5 g of 1,4-butanediol, 0.4 g of the dihydroxy cage-type silsesquioxane prepared in Example 1, 8.3 g of polypropylene glycol 2000 and 0.04 g of triethylenediamine. The temperature is raised to 80° C. to react for 3 h. After the reaction is completed, the essential oil sustained-release agent is prepared by suction filtration, washing and drying.

[0042] Embodiment 4 A method for preparing an essential oil sustained-release agent comprises the following steps:

[0043] (1) 200 mL of 20% ammonia water, 220 mL of deionized water and 3.1 g of hexadecyltrimethylammonium bromide were placed in a reactor, stirred at 65° C. and 255 r / min for 2 h, and then 14.8 g of tetraethyl orthosilicate was added and stirred for 2 h. After stirring, 4.8 g of 3-aminopropyltriethoxysilane was added dropwise and mixed for 8 h. The mixture was placed at 35° C. for crystallization for 24 h. The template was removed by filtration, washing, drying and ethanol extraction to prepare amino mesoporous silica.

[0044] (2) 9.8 g of sodium rosinate was dissolved in 100 mL of hydrochloric acid aqueous solution to adjust the pH value of the system to 6, 1.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.8 g of N-hydroxysuccinimide were added and stirred for 24 h, and then 0.5 g of amino-modified mesoporous silica was added and stirred for 24 h. After the reaction was completed, the functionalized mesoporous silica was filtered and dried to prepare the functionalized mesoporous silica.

[0045] (3) 1.7 g of functionalized mesoporous silica was mixed with 2 mL of mustard essential oil and subjected to ultrasonic treatment, and then filtered and dried to prepare supported mesoporous silica;

[0046] (4) 3 g of polyvinyl pyrrolidone was dissolved in deionized water at 85° C., cooled to room temperature, added with 2.9 g of Tween 80, stirred and emulsified, then added with 4.5 g of supported mesoporous silica, stirred and dispersed, then added with 9.6 g of isophorone diisocyanate, 0.7 g of 1,4-butanediol, 0.5 g of the dihydroxy cage silsesquioxane prepared in Example 1, 9.3 g of polypropylene glycol 2000 and 0.06 g of triethylenediamine, heated to 80° C. for reaction for 3 h, and after the reaction was completed, filtered, washed and dried to prepare an essential oil sustained-release agent.

[0047] Embodiment 5 A mildew-proof sheet containing plant essential oil comprises two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer comprises the following steps:

[0048] A1: immersing lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Example 2, and taking it out to prepare essential oil-modified lignin;

[0049] A2: The essential oil-modified lignin is sliced ​​to prepare an essential oil sustained-release layer.

[0050] Embodiment 6 A mildew-proof sheet containing plant essential oil comprises two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer comprises the following steps:

[0051] A1: immersing lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Example 3, taking it out, and preparing essential oil-modified lignin;

[0052] A2: The essential oil-modified lignin is sliced ​​to prepare an essential oil sustained-release layer.

[0053] Embodiment 7 A mildew-proof sheet containing plant essential oil comprises two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer comprises the following steps:

[0054] A1: immersing lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Example 4, taking it out, and preparing essential oil-modified lignin;

[0055] A2: The essential oil-modified lignin is sliced ​​to prepare an essential oil sustained-release layer.

[0056] Comparative Example 1 A method for preparing an essential oil sustained-release agent comprises the following steps:

[0057] (1) 185 mL of 25% ammonia water, 250 mL of deionized water and 2.7 g of hexadecyltrimethylammonium bromide were placed in a reactor, stirred at 55° C. and 260 r / min for 2 h, and then 13.4 g of tetraethyl orthosilicate was added and stirred for 8 h. The mixture was crystallized at room temperature for 24 h, filtered, washed, dried, calcined at 550° C. for 5 h, and cooled to obtain mesoporous silica.

[0058] (2) 1.7 g of mesoporous silica was mixed with 2 mL of mustard essential oil and subjected to ultrasonic treatment, and then filtered and dried to prepare supported mesoporous silica;

[0059] (3) Take 2.7 g of polyvinyl pyrrolidone and add it to deionized water at 85° C. to dissolve it. After cooling to room temperature, add 2.5 g of Tween 80 and stir to emulsify it. Then add 2.5 g of supported mesoporous silica and stir to disperse it. Then add 8.2 g of isophorone diisocyanate, 0.45 g of 1,4-butanediol, 0.2 g of the dihydroxy cage-type silsesquioxane prepared in Example 1, 7.1 g of polypropylene glycol 2000 and 0.02 g of triethylenediamine. The temperature is raised to 80° C. to react for 3 h. After the reaction is completed, the mixture is filtered, washed and dried to prepare an essential oil sustained-release agent.

[0060] Comparative Example 2 A method for preparing an essential oil sustained-release agent comprises the following steps:

[0061] (1) 185 mL of 25% ammonia water, 250 mL of deionized water and 2.7 g of hexadecyltrimethylammonium bromide were placed in a reactor, stirred at 55° C. and 260 r / min for 2 h, and then 13.4 g of tetraethyl orthosilicate was added and stirred for 2 h. After stirring, 4.5 g of 3-aminopropyltriethoxysilane was added dropwise and mixed for 8 h. The mixture was placed at 35° C. for crystallization for 24 h. The template was removed by filtration, washing, drying and ethanol extraction to prepare amino mesoporous silica.

[0062] (2) 9.3 g of sodium rosinate was dissolved in 100 mL of hydrochloric acid solution to adjust the pH value of the system to 5.5, 1.1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.5 g of N-hydroxysuccinimide were added and stirred for 24 h, and then 0.5 g of amino-modified mesoporous silica was added and stirred for 24 h. After the reaction was completed, the functionalized mesoporous silica was filtered and dried to prepare the functionalized mesoporous silica.

[0063] (3) 1.7 g of functionalized mesoporous silica was mixed with 2 mL of mustard essential oil and subjected to ultrasonic treatment, and then filtered and dried to prepare supported mesoporous silica;

[0064] (4) Take 2.7 g of polyvinyl pyrrolidone and add it to deionized water at 85° C. to dissolve it. After cooling to room temperature, add 2.5 g of Tween 80 and stir to emulsify it. Then add 2.5 g of supported mesoporous silica and stir to disperse it. Then add 8.2 g of isophorone diisocyanate, 0.45 g of 1,4-butanediol, 7.1 g of polypropylene glycol 2000 and 0.02 g of triethylenediamine. Heat to 80° C. to react for 3 h. After the reaction is completed, filter, wash and dry to prepare an essential oil sustained-release agent.

[0065] Comparative Example 3 A method for preparing an essential oil sustained-release agent comprises the following steps:

[0066] (1) 185 mL of 25% ammonia water, 250 mL of deionized water and 2.7 g of hexadecyltrimethylammonium bromide were placed in a reactor, stirred at 55° C. and 260 r / min for 2 h, and then 13.4 g of tetraethyl orthosilicate was added and stirred for 2 h. After stirring, 4.5 g of 3-aminopropyltriethoxysilane was added dropwise and mixed for 8 h. The mixture was placed at 35° C. for crystallization for 24 h. The template was removed by filtration, washing, drying and ethanol extraction to prepare amino mesoporous silica.

[0067] (2) 9.3 g of sodium rosinate was dissolved in 100 mL of hydrochloric acid solution to adjust the pH value of the system to 5.5, 1.1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.5 g of N-hydroxysuccinimide were added and stirred for 24 h, and then 0.5 g of amino-modified mesoporous silica was added and stirred for 24 h. After the reaction was completed, the functionalized mesoporous silica was filtered and dried to prepare the functionalized mesoporous silica.

[0068] (3) 1.7 g of functionalized mesoporous silica was mixed with 2 mL of mustard essential oil and subjected to ultrasonic treatment. The mixture was filtered and dried to prepare an essential oil sustained-release agent.

[0069] Comparative Example 4 A mildew-proof sheet containing plant essential oil comprises two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer comprises the following steps:

[0070] A1: immersing lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Comparative Example 1, and taking it out to prepare essential oil-modified lignin;

[0071] A2: The essential oil-modified lignin is sliced ​​to prepare an essential oil sustained-release layer.

[0072] Comparative Example 5 A mildew-proof sheet containing plant essential oil comprises two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer comprises the following steps:

[0073] A1: immersing lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Comparative Example 2, and taking it out to prepare essential oil-modified lignin;

[0074] A2: The essential oil-modified lignin is sliced ​​to prepare an essential oil sustained-release layer.

[0075] Comparative Example 6 A mildew-proof sheet containing plant essential oil comprises two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer comprises the following steps:

[0076] A1: immersing lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Comparative Example 3, and taking it out to prepare essential oil-modified lignin;

[0077] A2: The essential oil-modified lignin is sliced ​​to prepare an essential oil sustained-release layer.

[0078] Performance Testing

[0079] (1) Sustained-release performance at room temperature: The essential oil sustained-release agents prepared in Examples 2-4 and Comparative Examples 1-3 were evenly spread on a culture dish and placed in an open environment at 25° C. (room temperature) for 60 days. The essential oil content in the essential oil sustained-release agent was determined using a TU-1950 UV-visible spectrophotometer to obtain the essential oil release amount. The data results are shown in Table 1.

[0080] (2) High-temperature sustained-release performance: The essential oil sustained-release agents prepared in Examples 2-4 and Comparative Examples 1-3 were evenly spread on a culture dish, placed in an oven at 80° C. for drying for 30 h, and the essential oil release amount was obtained by the mass change. The data results are shown in Table 1.

[0081] (3) Long-term antibacterial and mildew-proof performance: The essential oil sustained-release agents prepared in Examples 2-4 and Comparative Examples 1-3 were placed in humid air at room temperature and a humidity of 80% RH for different days, and the antibacterial performance of the essential oil sustained-release agents was tested by the Oxford cup method. Aspergillus niger and Trichoderma viride were inoculated on PDA culture medium, respectively, and cultured in a constant temperature and humidity chamber at a temperature of (28±2)°C and a relative humidity of (85±5)% for several days. After the colonies covered the entire culture medium, they were set aside. A sterile Oxford cup was placed in the culture medium, and 0.1 mL of 1% essential oil sustained-release agent prepared with 0.9% physiological saline was slowly injected into the Oxford cup, and the cup was transferred to a constant temperature and humidity chamber for continued culture for 7 days. After the diffusion of the solution in the Oxford cup was completed, the diameter of the antibacterial zone was measured. Each group was tested in parallel 5 times, and the mean was calculated. The data results are shown in Table 1.

[0082] Table 1 Test results of sample performance

[0083]

[0084] As can be seen from the data in Table 1, the essential oil sustained-release agent prepared by Examples 2-4 of the present invention has an essential oil release of less than 22% after being placed at room temperature for 60d, and an essential oil release of less than 25% after being treated at 80°C for 30h, indicating that it has a significant sustained-release effect under normal temperature and high temperature conditions, and can still maintain a good sustained-release antibacterial and mildew-proof effect in a humid environment. Wherein in Comparative Example 1, mesoporous silica is used as a carrier to load essential oil, and the essential oil sustained-release effect measured is poorer than that of Examples 2-4, because sodium rosinate is not grafted after mesoporous silica is amino-treated, and no dihydroxy cage-type silsesquioxane component is added in Comparative Example 2, and the high-temperature essential oil release and sustained-release antibacterial and mildew-proof effect measured are poorer than those of Examples 2-4, indicating that the addition of dihydroxy cage-type silsesquioxane can enhance the sustained-release effect of plant essential oils in high temperature and humid environments, and polyurethane wall materials are not prepared in Comparative Example 3, and the essential oil sustained-release effect measured is the most significantly reduced than that of Examples 2-4.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0086] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A mildew-proof sheet containing plant essential oil, characterized in that: The invention comprises two epidermal layers and an essential oil sustained-release layer arranged between the two epidermal layers. The preparation method of the essential oil sustained-release layer comprises the following steps: A1: immersing lignin in a solution containing an essential oil sustained-release agent, taking it out, and preparing essential oil-modified lignin; A2: preparing essential oil slow-release layer by modifying lignin with essential oil; The essential oil sustained-release agent is prepared by using functionalized mesoporous silica loaded with plant essential oil as a core material, introducing dihydroxy cage-type silsesquioxane into the main chain of polyurethane and then wrapping the core material, wherein the functionalized mesoporous silica is prepared by grafting sodium rosin acid with amino mesoporous silica by chemical reaction.

2. The anti-mildew sheet containing plant essential oil according to claim 1, characterized in that: The epidermis layer is a breathable membrane; and the solution is ethanol.

3. The anti-mildew sheet containing plant essential oil according to claim 1, characterized in that: The preparation method of the essential oil sustained-release agent comprises the following steps: (1) Ammonia water, deionized water and hexadecyltrimethylammonium bromide are placed in a reactor, stirred at 50-65° C. and 200-300 r / min for 2-3 h, and then tetraethyl orthosilicate is added and stirred for 1-3 h. After stirring, 3-aminopropyltriethoxysilane is added dropwise and mixed for 6-8 h. The mixture is placed at 30-35° C. for crystallization at a constant temperature for 20-24 h. The template is removed by filtering, washing, drying and ethanol extraction to prepare amino mesoporous silica. (2) dissolving sodium rosin acid in a hydrochloric acid aqueous solution to adjust the pH value of the system to 5.5-6, adding 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide and stirring and mixing for 20-24 hours, then adding amino mesoporous silica and continuing to stir and react for 18-24 hours. After the reaction is completed, filtering and drying are performed to prepare functionalized mesoporous silica; (3) mixing the functionalized mesoporous silica with plant essential oil and subjecting the mixture to ultrasonic treatment, filtering and drying to prepare supported mesoporous silica; (4) Polyvinyl pyrrolidone is dissolved in deionized water at 80 to 90° C., cooled to room temperature, Tween 80 is added and stirred for emulsification, and then supported mesoporous silica is added and stirred for dispersion, and then isophorone diisocyanate, 1,4-butanediol, dihydroxy cage silsesquioxane, polypropylene glycol 2000 and triethylenediamine are added, and the temperature is raised to 65 to 80° C. for reaction for 1 to 3 hours. After the reaction is completed, the essential oil sustained-release agent is prepared by suction filtration, washing and drying.

4. The anti-mildew sheet containing plant essential oil according to claim 3, characterized in that: The mass fraction of ammonia water in the step (1) is 20-30%, and the addition ratio of ammonia water, deionized water, hexadecyltrimethylammonium bromide, tetraethyl orthosilicate and 3-aminopropyltriethoxysilane is 150-200 mL: 200-300 mL: 2-3.2 g: 10-15.5 g: 3.6-5 g.

5. The anti-mildew sheet containing plant essential oil according to claim 3, characterized in that: In the step (2), the mass ratio of sodium rosinate to amino-modified mesoporous silica is 7.5-10:0.

5.

6. The anti-mildew sheet containing plant essential oil according to claim 3, characterized in that: In the step (3), the plant essential oil is one or more of tea tree essential oil, mustard essential oil, cinnamon essential oil, garlic essential oil, citronella essential oil, rose essential oil, wormwood essential oil, peppermint essential oil, lemon essential oil, clove essential oil, and lavender essential oil.

7. The anti-mildew sheet containing plant essential oil according to claim 3, characterized in that: In the step (4), the mass ratio of polyvinyl pyrrolidone, Tween 80, supported mesoporous silica, isophorone diisocyanate, 1,4-butanediol, dihydroxy cage silsesquioxane, polypropylene glycol 2000 and triethylenediamine is 2.5-3: 2.5-3: 2.5-5: 8-9.6: 0.4-0.7: 0.2-0.6: 7-10: 0.02-0.

06.

8. The anti-mildew sheet containing plant essential oil according to claim 3, characterized in that: The method for preparing dihydroxy cage-type silsesquioxane in step (4) comprises the following steps: ① Dissolve sodium hydroxide in deionized water, add isopropanol solvent, then add phenyltrimethoxysilane and stir to mix, place under nitrogen atmosphere at 80-95° C. for reflux reaction for 3-5 hours, then cool to room temperature, continue stirring to react for 10-15 hours, and after the reaction is completed, perform rotary evaporation and drying to obtain a primary product; ② Take the initial product, add tetrahydrofuran solvent and triethylamine, add methyltrichlorosilane in a nitrogen atmosphere, stir and react for 8 to 12 hours, then place it in an ice water bath and add deionized water to dissolve excess methyltrichlorosilane and by-products. After the reaction is completed, add toluene to extract and separate the organic layer, wash, filter, rotary evaporate and dry to prepare dihydroxy cage-type silsesquioxane.

9. A method for preparing the anti-mildew sheet containing plant essential oil according to claim 1, characterized in that: The method comprises the following steps: arranging an essential oil sustained-release layer between two epidermal layers and performing composite pressing.

10. An application of an anti-mildew sheet containing plant essential oil according to any one of claims 1 to 8, characterized in that: The anti-mildew sheet containing plant essential oil is used for food preservation and anti-mildew of shoes, clothing, bags and sofa products.

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