Metal organic framework material with fragrance slow-release function and preparation method of metal organic framework material

Abstract

The invention discloses a metal organic framework material with an aroma slow-release function and a preparation method thereof, the metal organic framework material comprises a metal organic framework material and a polymer matrix, the metal organic framework material is prepared through a melt spinning process, and aroma organic molecules are packaged in internal pore channels of the metal organic framework material. The preparation method comprises the following steps: packaging aroma organic molecules into a metal organic framework material through an impregnation method to obtain the metal organic framework composite material with an aroma slow-release effect; blending the metal organic framework composite material with sodium carboxymethyl cellulose, adding a proper amount of water, extruding and cutting to obtain metal organic framework composite material master batch; and blending the metal organic framework composite material master batch with a polymer matrix, and preparing fibers through a melt spinning process to obtain the metal organic framework fiber material with the aroma slow-release effect. According to the invention, the loading capacity of the functional MOFs material can be remarkably improved, and meanwhile, the functional MOFs material has relatively high mechanical strength.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer composite materials, and in particular relates to a metal organic framework material with a fragrance sustained-release function and a preparation method thereof. Background Art

[0002] With the upgrading of consumption and the rapid growth of demand for functional materials, the market has put forward more stringent performance requirements for aroma sustained-release materials, including key indicators such as long-term sustained-release, high loading rate, environmental stability and mechanical strength. However, traditional aroma carrier materials such as porous polymers and cyclodextrins have obvious limitations in comprehensive performance and are difficult to meet the needs of high-end application scenarios. MOFs materials, with their unique structural advantages, including precisely controllable nanoscale pores (0.5-3.0nm), ultra-high specific surface area and rich surface chemical properties, provide a new solution to break through the bottleneck of existing technologies. Through molecular-level structural design, the size matching and specific interaction between aroma molecules and MOFs pores can be achieved, thereby significantly improving the loading rate and sustained-release performance. More importantly, the structural designability of MOFs materials enables them to be customized according to the physical and chemical properties of different aroma molecules. This feature creates conditions for the development of high-performance and multifunctional aroma sustained-release systems. When preparing functional MOFs fiber materials with aroma sustained-release effects, achieving high loading capacity and strong mechanical strength are two major technical challenges.

[0003] The key technical challenge in preparing functional MOF-based fiber materials with aroma-sustaining properties is the synergistic optimization of high MOF loading and mechanical strength. Conventional preparation processes often struggle to balance these two key performance criteria, primarily due to the following technical bottlenecks: First, while a higher MOF content can increase aroma molecule loading, it can also hinder fiber formation during the spinning process. Excessively increasing the polymer matrix ratio to improve mechanical strength significantly reduces the material's effective loading capacity. This performance trade-off severely limits the material's practical application. Second, conventional spinning processes have a narrow temperature control window. Excessively high temperatures can damage the MOF pore structure, affecting aroma molecule loading and sustained-release properties, while excessively low temperatures make it difficult to ensure good fiber formation. Furthermore, the difficulty in controlling the uniformity of MOF particle dispersion during spinning leads to a decrease in the material's mechanical properties. More critically, existing preparation techniques face challenges with long-term use, including structural damage to the MOFs under mechanical stress and delamination of the fiber-matrix interface, severely impacting the durability of the aroma-sustaining properties and the material's lifespan. Summary of the Invention

[0004] In order to address the deficiencies of the prior art, the purpose of the present invention is to provide a metal-organic framework material with an aroma sustained-release function and a preparation method thereof, develop a melt spinning technology for MOFs fiber materials to improve their dispersibility in the polymer matrix, and establish an interface enhancement mechanism to enhance the mechanical properties of composite materials through molecular-level interactions, which can significantly increase the loading capacity of functional MOFs materials while also having higher mechanical strength.

[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0006] A metal-organic framework material with a sustained-release aroma function comprises a metal-organic framework material and a polymer matrix, and is prepared by a melt spinning process. Aroma organic molecules are encapsulated in the internal pores of the metal-organic framework material.

[0007] Preferably, the aforementioned metal organic framework material is a Zr-MOFs material or an Al-MOFs material, the ligand of the Zr-MOFs material is 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, and the ligand of the Al-MOFs material is 2,5-furandicarboxylic acid or terephthalic acid.

[0008] Preferably, the aforementioned aroma organic molecules are limonene or tea polyphenols.

[0009] Preferably, the aforementioned polymer matrix is ​​polyethylene terephthalate.

[0010] The method for preparing the metal-organic framework material with aroma sustained-release function comprises the following steps:

[0011] S1. Encapsulating the aroma organic molecules into the metal-organic framework material by an impregnation method to obtain a metal-organic framework composite material with an aroma sustained-release effect;

[0012] S2, blending the metal-organic framework composite material with sodium carboxymethyl cellulose, adding an appropriate amount of water, and extruding and cutting the material to prepare a metal-organic framework composite material masterbatch;

[0013] S3. The metal organic framework composite material masterbatch is blended with a polymer matrix, and the mixture is made into fibers through a melt spinning process to obtain a metal organic framework fiber material with an aroma sustained-release effect.

[0014] Preferably, the aforementioned metal organic framework material needs to be activated before use. The specific steps are: activating the metal organic framework material under vacuum conditions and high temperature, and then introducing inert gas protection after cooling.

[0015] Preferably, in the aforementioned step S1, the specific impregnation encapsulation method is: dissolving the aroma organic molecules in a solvent, mixing with the metal organic framework material, stirring, filtering and drying to obtain the metal organic framework composite material.

[0016] Preferably, the aforementioned solvent is ethanol or water, and the concentration of the aroma organic molecule solution is 1-10 g / mL; after mixing, the concentration of the metal organic framework material is 0.1-10 g / mL.

[0017] Preferably, in the aforementioned step S3, the mass ratio of the metal organic framework composite material masterbatch to the polymer matrix is ​​1:1-25; the melt spinning temperature is 200-300°C, the fineness is 100-200d / 30-60f, and the winding speed is 1000-3500r / min.

[0018] Preferably, in the aforementioned step S2, the amount of sodium carboxymethyl cellulose added is 4%-10% of the metal organic framework composite material, the amount of water added is 0.5-1.5 times of the metal organic framework composite material; and the extrusion temperature is 30-45°C.

[0019] Preferably, in the aforementioned step S2, the specific method for preparing the masterbatch is: weighing 5-12 g of the metal-organic framework composite material and 4%-10% of sodium carboxymethyl cellulose respectively, placing them in a high mixer and stirring for 10-15 minutes, and then spraying 5-12 mL of water into the system during the stirring process, and stirring for 13-20 minutes to obtain a premix, and then placing the premix in a twin-screw extruder for extrusion, the screw aspect ratio is 44, the screw diameter is 22 mm, the screw speed is 360 rpm, the extrusion temperatures in each zone are 32°C, 33°C, 35°C, 40°C, 40°C, 40°C, and 43°C, respectively, and after grinding and pelletizing, and air cooling, a metal-organic framework composite masterbatch with an aroma sustained-release effect is obtained.

[0020] An application of the above-mentioned metal organic framework material with aroma sustained release function in the preparation of flavoring material.

[0021] The present invention is beneficial in that:

[0022] (1) The present invention achieves efficient and selective encapsulation of aroma molecules by precisely controlling the pore size and surface chemical properties of MOFs, and uses a melt spinning process to prepare MOFs materials with an aroma sustained-release effect into functional composite fiber materials. The MOFs-based composite fiber materials prepared by this method exhibit multiple advantages. By precisely matching the MOFs pore structure with the aroma molecules, a high molecular loading rate and controlled release characteristics are achieved. The melt spinning process significantly improves the mechanical strength of the fiber material while maintaining the integrity of the MOFs porous structure. The preparation method has the characteristics of simple process, low energy consumption, and ease of large-scale production.

[0023] (2) The present invention not only overcomes the shortcomings of low loading rate and poor mechanical properties of traditional aroma sustained-release materials, but also provides an innovative technical path for the industrial preparation of functional MOFs fiber materials, and has broad application prospects in the fields of smart textiles, functional packaging materials, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 These are the enlarged cold field emission scanning electron microscope images of the Zr-MOF materials prepared in Examples 1 to 3 ((a) Zr-MOF, (b) Al-MOF-1, (c) Al-MOF-2);

[0025] Figure 2 These are the enlarged cold field emission scanning electron microscope images of the fiber materials prepared in Examples 1 to 6 ((ab)Le-fiber(cd)Le-fiber-1(ef)Le-fiber-2(gh)Tp-fiber(ij)Tp-fiber-1(kl)Tp-fiber-2). DETAILED DESCRIPTION

[0026] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] The preparation method of the antibacterial functionalized metal organic framework material comprises the following steps:

[0029] (1) Activation of Zr-MOF materials

[0030] First, accurately weigh 10 g of Zr-MOFs (ligand: 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene) material and place it in a vacuum drying oven. Subsequently, the drying oven is evacuated with an oil pump to ensure that the system is in a low-pressure environment. Under programmed temperature control conditions, the temperature is raised to 120 ° C at a heating rate of 5 ° C / min, and maintained at this temperature for 720 minutes to achieve full activation of the material. After the heat treatment is completed, the system is cooled to room temperature at a cooling rate of 10 ° C / min. Finally, an inert gas (N2 or Ar) is introduced into the drying oven until the air pressure in the box returns to normal pressure.

[0031] (2) Zr-MOF materials encapsulate organic molecules with antibacterial effects

[0032] Limonene (Le) was dissolved in ethanol to form a 1g / mL solution. A certain amount of activated Zr-MOF material was weighed and added to form a 0.1g / mL suspension. The mixture was stirred for 24 hours, and the solid material was collected by filtration to obtain the Le-Zr-MOF material with a sustained aroma release effect.

[0033] (3) Preparation of Le-Zr-MOF masterbatch

[0034] 5 g of Le-Zr-MOF and 5% of sodium carboxymethyl cellulose were weighed respectively, placed in a high mixer and stirred for 10 minutes, and then during the stirring process, 5 mL of water was sprayed into the system, and then stirred for 13 minutes to obtain a premix, which was then placed in a twin-screw extruder for extrusion. The screw aspect ratio was 44, the screw diameter was 22 mm, the screw speed was 360 rpm, and the extrusion temperatures in each zone were 32°C, 33°C, 35°C, 40°C, 40°C, 40°C, and 43°C, respectively. After grinding and pelletizing, and air cooling, Le-Zr-MOF masterbatch with aroma sustained-release effect was obtained.

[0035] (4) Preparation of MOFs fiber materials with aroma sustained release effect by melt spinning

[0036] The prepared Le-Zr-MOF masterbatch and polyethylene terephthalate (PET) chips were weighed in a ratio of 1:25, blended and placed in a melt spinning machine. The molten liquid was extruded from the spinneret, air-cooled, oiled and wound. The spinning temperature was set to 200°C, the fineness was 100d / 30f, and the winding speed was 2500r / min to obtain functional polyester Le-fiber fiber material.

[0037] Example 2

[0038] The preparation steps of this embodiment are the same as those of Example 1, with the specific difference being that the metal organic framework material is Al-MOF-1 (ligand: 2,5-furandicarboxylic acid), and Le-Al-MOF-1 material is prepared, which is then melt-spun to obtain Le-fiber-1 fiber material.

[0039] Example 3

[0040] The preparation steps of this embodiment are the same as those of Example 1, with the specific difference being that the metal organic framework material is Al-MOF-2 (ligand: terephthalic acid), and Le-Al-MOF-2 material with antibacterial effect is prepared, which is then melt-spun to obtain Le-fiber-2 fiber material.

[0041] Example 4

[0042] The preparation steps of this embodiment are the same as those of embodiment 1, with the specific difference being that the aroma organic molecule is tea polyphenols (Tp), and a Tp-fiber fiber material is obtained.

[0043] Example 5

[0044] The preparation steps of this embodiment are the same as those of embodiment 2, with the specific difference being that the aroma organic molecules are tea polyphenols, and Tp-fiber-1 fiber material is obtained.

[0045] Example 6

[0046] The preparation steps of this embodiment are the same as those of embodiment 3, with the specific difference being that the aroma organic molecules are tea polyphenols, and Tp-fiber-2 fiber material is obtained.

[0047] Comparative Example 1

[0048] The specific difference between this comparative example and Example 1 is that: after 0.2g of limonene (Le) aroma organic molecules were mixed with 0.25g of sodium carboxymethyl cellulose, an appropriate amount of water was added to directly prepare a masterbatch without loading through MOF particles to obtain fiber-1 fiber material.

[0049] Performance testing

[0050] (1) Morphology analysis: The functional fiber materials in Examples 1 to 6 were sampled and the metal organic framework materials (such as Figure 1 As shown) and functional fiber materials (such as Figure 2 morphology analysis was performed.

[0051] like Figure 1 and Figure 2 As shown, the preparation method using the melt spinning technology of the present invention will not cause the morphology of the MOFs material to change and will not cause the material skeleton to collapse, thereby proving that the preparation method adopted by the present invention is completely feasible. This discovery provides a solid experimental basis for the industrial application of functional MOFs materials in the field of aroma sustained release.

[0052] (2) Aroma sustained release performance:

[0053] 0.6 g of each of the materials from Examples 1-6 and Comparative Example 1 were weighed and exposed to air for 10 days. The samples were then wrapped with 180-mesh standard gauze and immersed in deionized water or anhydrous ethanol. The concentration of the flavoring agent in the extract was analyzed by high-performance liquid chromatography to evaluate its release rate. The results are shown in Table 1.

[0054] Table 1 Aroma sustained release performance of materials

[0055]

[0056] As shown in Table 1, after the aroma substances are loaded by MOF particles, their sustained-release characteristics are effectively improved. The concentration of the aroma agent in the extract of the fiber material that is not loaded by MOF particles is low, and the release speed is very fast, resulting in poor actual application effect.

[0057] (3) Mechanical strength: The mechanical strength of the materials in Examples 1 to 6 and Comparative Example 1 was tested according to GB / T 14337-2022. The specific results are shown in Table 2.

[0058] Table 2 Mechanical strength of materials

[0059] sample Breaking strength cN / dtex Elongation at break % Le-fiber 7.8 7.6 Le-fiber-1 7.9 7.2 Le-fiber-2 8.1 7.3 Tp-fiber 7.7 7.6 Tp-fiber-1 7.6 7.3 Tp-fiber-2 8.1 7.3 fiber-1 5.4 9.0

[0060] As shown in Table 2, compared with fiber-1, the fibers prepared by melt spinning in Examples 1 to 6 can significantly improve the mechanical strength of the fiber materials by using MOF particle materials.

[0061] 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 above embodiments do not limit the present invention in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the scope of protection of the present invention.

Claims

1. A metal-organic framework material with aroma sustained-release function, characterized in that: The invention comprises a metal organic framework material and a polymer matrix, and is prepared by a melt spinning process. The internal pores of the metal organic framework material are encapsulated with aromatic organic molecules.

2. The metal-organic framework material with aroma sustained-release function according to claim 1, characterized in that: The metal organic framework material is a Zr-MOFs material or an Al-MOFs material, the ligand of the Zr-MOFs material is 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, and the ligand of the Al-MOFs material is 2,5-furandicarboxylic acid or terephthalic acid.

3. The metal-organic framework material with aroma sustained-release function according to claim 1, characterized in that: The aroma organic molecules are limonene or tea polyphenols.

4. The metal-organic framework material with aroma sustained-release function according to claim 1, characterized in that: The polymer matrix is ​​polyethylene terephthalate.

5. The method for preparing a metal-organic framework material with aroma sustained-release function according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Encapsulating the aroma organic molecules into the metal-organic framework material by an impregnation method to obtain a metal-organic framework composite material with an aroma sustained-release effect; S2, blending the metal-organic framework composite material with sodium carboxymethyl cellulose, adding an appropriate amount of water, and extruding and cutting the material to prepare a metal-organic framework composite material masterbatch; S3. The metal organic framework composite material masterbatch is blended with a polymer matrix, and the mixture is made into fibers through a melt spinning process to obtain a metal organic framework fiber material with an aroma sustained-release effect.

6. The method for preparing a metal-organic framework material with aroma sustained-release function according to claim 5, characterized in that: The metal organic framework material needs to be activated before use. The specific steps are: activating the metal organic framework material under vacuum conditions and high temperature, and then introducing inert gas protection after cooling.

7. The method for preparing a metal-organic framework material with aroma sustained-release function according to claim 5, characterized in that: In step S1, the specific impregnation encapsulation method is: dissolving the aroma organic molecules in a solvent, mixing with the metal organic framework material, filtering and drying to obtain a metal organic framework composite material; the solvent is ethanol or water, and the concentration of the aroma organic molecule solution is 1-10 g / mL; after mixing, the concentration of the metal organic framework material is 0.1-10 g / mL.

8. The method for preparing a metal-organic framework material with aroma sustained-release function according to claim 7, characterized in that: In the step S2, the amount of sodium carboxymethyl cellulose added is 4%-10% of the metal organic framework composite material, and the amount of water added is 0.5-1.5 times the metal organic framework composite material; the extrusion temperature is 30-45°C.

9. The method for preparing a metal-organic framework material with aroma sustained-release function according to claim 5, characterized in that: In step S3, the mass ratio of the metal organic framework composite material masterbatch to the polymer matrix is ​​1:1-25; the melt spinning temperature is 200-300°C, the fineness is 100-200 d / 30-60 f, and the winding speed is 1000-3500 r / min.

10. Use of the metal organic framework material with aroma sustained release function according to any one of claims 1 to 4 in the preparation of a flavoring material.

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