Amphiphilic metal-organic framework nanoparticles and their applications

Abstract

This invention provides amphiphilic metal-organic framework nanoparticles and their applications. The invention utilizes a liquid-phase co-deposition reaction of nickel-cobalt metal salts with hydrophobic terephthalic acid ligands and hydrophilic 2-aminoterephthalic acid ligands to synthesize amphiphilic metal-organic framework nanoparticles with different amphiphilic properties. Using these nanoparticles as compatibilizers, polylactic acid, polybutylene succinate, and the amphiphilic metal-organic framework nanoparticles are mixed using a melt blending method to prepare a blend material. These amphiphilic metal-organic framework nanoparticles not only improve the compatibility of the blend and effectively reduce the phase region size of the dispersed phase, but also achieve simultaneous improvement in strength and toughness with a relatively low filler loading. Compared with traditional nanoparticle compatibilization methods, the amphiphilic metal-organic framework nanoparticles developed in this invention have advantages such as simple preparation process, controllable structure, and significant compatibilization effect.

Description

Technical Field

[0001] This invention belongs to the field of polymer blends and nanomaterials technology, and more specifically, relates to an amphiphilic metal-organic framework nanoparticle and its application in compatibilizing incompatible blends. Background Technology

[0002] With the development of society and the economy, polymer materials have gradually occupied an indispensable position in various fields due to their low price, excellent performance, and multifunctionality. However, because their products are not easily degraded and are produced in large quantities, they impose a huge burden on the environment. In recent years, biodegradable plastics have been considered one of the effective ways to solve the problem of plastic pollution. Among biodegradable bio-based plastics, polylactic acid (PLA) is an ideal choice because it has good strength, processing performance, and biodegradability. However, PLA's brittleness, moisture barrier properties, and heat resistance limitations restrict its application range. Therefore, biodegradable blends are usually prepared by melt blending PLA and polybutylene succinate (PBS). However, studies have found that blends prepared from PLA and PBS have poor compatibility and are prone to micro-phase separation, resulting in poor mechanical properties of the blends.

[0003] To improve the compatibility between components in blends, various compatibilizers are widely used in actual production. Traditional compatibilizers are typically amphiphilic copolymers, which possess good two-phase compatibility and reduce interfacial tension by agglomerating at the interface, thereby improving component compatibility, inhibiting phase separation, and achieving blend compatibility. However, when using such multi-component copolymers as compatibilizers, their immiscible elastomer interblocks tend to accumulate at the blend interface, and their distribution within the blend system is influenced by relative molecular mass, thus limiting the enhancement of blend compatibility and mechanical properties.

[0004] Janus particles are particles with two or more regions possessing different chemical and physical properties. Due to their combination of the selective interaction capabilities of diblock copolymers and the stability of nanoparticles, they can be used as compatibilizers to stabilize blend interfaces and improve compatibilization. Changing the size, shape, or surface modification of Janus particles can alter their amphiphilicity, enabling different functional applications. The performance of Janus particles depends on the design of their internal and surface composition; therefore, the precise and large-scale synthesis of functionalized Janus particles is challenging. The amphiphilic metal-organic framework nanoparticles prepared in this invention are periodic network structure materials formed through the self-assembly of metal ions and organic ligands. Compared to traditional compatibilizers, which are prone to problems such as detachment or entanglement at the interface, amphiphilic metal-organic framework nanoparticles can be dispersed at the interface, effectively reducing the phase region size of the dispersed phase, thereby improving the compatibility and mechanical properties of the blend material. Compared to Janus particles, these nanoparticles can directly achieve amphiphilic regulation by changing the type and mass ratio of organic ligands. While meeting functionalization requirements, the preparation process is simpler and easier, the structure and properties of the compatibilizer are easier to design, and the prepared compatibilized blends have better mechanical properties, showing significant advantages. Summary of the Invention

[0005] This invention provides a method for using amphiphilic metal-organic framework nanoparticles as compatibilizers. This method effectively reduces the interfacial tension between the two phases and improves interfacial adhesion by dispersing the nanoparticles at the interface of the blend system, thereby enhancing the compatibility and mechanical properties of the composite material and achieving a good compatibilization effect. During melt blending, the nanoparticles can overcome the limitations of traditional compatibilizers, resulting in a more efficient compatibilization effect and improved performance of incompatible blends. This method has advantages such as simple operation, strong controllability in compatibilizer design, and excellent mechanical properties in the prepared compatibilized composite material.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides amphiphilic metal-organic framework nanoparticles, which are prepared by the following method:

[0008] Metal salts and ligands are dissolved in a mixed solvent of dimethylformamide, ethanol and deionized water, and triethylamine is added. Nucleation is achieved by sonication for 1-2 hours (preferably 1 hour). The reaction is stirred at room temperature for 4-6 hours (5.5 hours in one embodiment of the present invention). The resulting reaction solution is post-treated to obtain amphiphilic metal-organic framework nanoparticles.

[0009] The molar ratio of the metal salt to the ligand is 1:1 to 1.1 (preferably 1:1), the metal salt is a mixture of nickel salt and cobalt salt, and the molar ratio of the nickel salt to the cobalt salt is 1:1 to 1.05 (preferably 1:1); the ligand is a mixture of terephthalic acid and 2-aminoterephthalic acid, and the molar ratio of the terephthalic acid to the ligand is 2-8:10 (preferably 5:10); the molar ratio of the triethylamine to the ligand is 1:7.6 to 9.5 (preferably 1:7.67).

[0010] The amount of the metal salt is the sum of the amounts of the nickel salt and the cobalt salt, and the amount of the ligand is the sum of the amounts of terephthalic acid and 2-aminoterephthalic acid.

[0011] In one embodiment of the present invention, the nickel salt is nickel chloride or nickel sulfate, and the cobalt salt is cobalt chloride or cobalt sulfate.

[0012] DMF was chosen as the solvent because it can dissolve the organic ligands at room temperature, is a common organic solvent, and is inexpensive. Ethanol and water act as solvent polarity regulators, which are beneficial for MOF growth.

[0013] Furthermore, the mixed solvent is composed of dimethylformamide, ethanol and deionized water in a volume ratio of 32:2 to 5:2 to 5 (preferably 32:2:2).

[0014] In one embodiment of the present invention, the post-processing is as follows: the reaction solution is centrifuged, the resulting precipitate is washed with ethanol by centrifugation, and dried (the recommended temperature is 60°C and the drying time is 12h) to obtain the BDC:NH2-BDC nanoparticles.

[0015] The ultrasound time is 1 hour. During the ultrasound process, circulating water must be continuously introduced to prevent the water temperature in the ultrasound pool from becoming too high due to prolonged ultrasound, which would affect the nucleation of MOF crystals.

[0016] Secondly, the present invention provides an application of the above-mentioned amphiphilic metal-organic framework nanoparticles in compatibilized incompatible blends; the incompatible blends include polymer A and polymer B, wherein polymer A is polylactic acid (PLA) and polymer B is an aliphatic polyester plastic.

[0017] Preferably, the polymer B is one or both of polybutylene succinate (PBS) and polycaprolactone (PCL), and more preferably polybutylene succinate.

[0018] Specifically, the application involves: melt-blending incompatible polymers A and B with the amphiphilic metal-organic framework nanoparticles, followed by molding to obtain a blend; the mass of polymer A is 50-70% (preferably 70%) of the total mass of polymers A and B; and the mass of the amphiphilic metal-organic framework nanoparticles is 0.1-0.5% (preferably 0.1%) of the total mass of polymers A and B.

[0019] In one embodiment of the present invention, polymer A is polylactic acid (polylactic acid resin 4032D), polymer B is polybutylene succinate (polybutylene succinate TH801), the mass of polymer A is 70% of the total mass of polymer A and polymer B, and the mass of the amphiphilic metal-organic framework nanoparticles is 0.1% of the total mass of polymer A and polymer B.

[0020] In one embodiment of the present invention, the equipment used for melt blending is a Hacker torque rheometer, the blending temperature is 180°C, the blending speed is 60 rpm, and the blending time is 8 min.

[0021] In one embodiment of the present invention, the molding temperature is 180°C, the pre-compression pressure is 4 MPa, the pre-compression time is 1 min, the holding pressure is 10 MPa, and the holding time is 2 min.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention uses amphiphilic metal-organic framework nanoparticles as compatibilizers and fillers. The preparation process is simple, and with a small amount of filler added, it can significantly improve the compatibility of blended materials and enhance their mechanical properties. Attached Figure Description

[0024] Figure 1 The stress-strain curves of PLA / PBS composite materials and the stress-strain curves of composite materials prepared by adding 0.1 wt% of amphiphilic metal-organic framework nanoparticles with different ligand ratios to PLA / PBS are shown.

[0025] Figure 2 Tensile fracture morphology of a composite material prepared by adding 0.1 wt% of amphiphilic metal-organic framework nanoparticles with a ligand ratio of 5:5 to PLA / PBS.

[0026] Figure 3 Low-temperature brittle fracture cross-sectional morphology of a composite material prepared by adding 0.1 wt% of amphiphilic metal-organic framework nanoparticles with a ligand ratio of 5:5 to PLA / PBS.

[0027] Figure 4The image shows the tensile cross-sectional morphology of the PLA / PBS composite material in Comparative Example 1.

[0028] Figure 5 The image shows the cross-sectional morphology of the PLA / PBS composite material at low temperature during brittle fracture in Comparative Example 1.

[0029] Figure 6 The stress-strain curves of the PLA / PCL composite material in Comparative Example 2 and the stress-strain curves of the composite material after adding 0.1 wt% of amphiphilic metal-organic framework nanoparticles with a ligand ratio of 5:5 to PLA / PCL in Example 8 are shown. Detailed Implementation

[0030] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry. The raw materials and composite materials in all embodiments are vacuum dried under the same conditions. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0031] Example 1

[0032] First, nanoparticles with a ligand ratio of BDC:NH2-BDC = 5:5 were prepared. 0.0892 g and 0.375 mmol of NiCl2·6H2O, 0.0893 g and 0.375 mmol of CoCl2·6H2O, 0.0623 g and 0.375 mmol of terephthalic acid (BDC), and 0.0679 g and 0.375 mmol of 2-aminoterephthalic acid (NH2-BDC) were weighed. These four reagents were dissolved together in a mixed solution consisting of 32 ml dimethylformamide (DMF), 2 ml ethanol, and 2 ml deionized water. After complete dissolution, 0.8 ml of triethylamine was added to the solution, and the solution was sonicated in an ultrasonic bath for 1 hour. After sonication, stirring was continued at room temperature for 5.5 hours. The resulting solution was centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. The precipitate was then washed with 15 ml of ethanol, centrifuged at 6000 rpm for 3 min, and the supernatant ethanol was discarded. This process was repeated three times. Finally, the precipitate was dried in a vacuum oven at 60°C for 12 h to prepare BDC:NH2-BDC = 5:5 nanoparticles. Subsequently, 35.0 g of polylactic acid resin (4032D, from Natureworks, USA), 15 g of polybutylene succinate (TH801, from Xinjiang Lanshan Tunhe Chemical Co., Ltd.), and 0.05 g of the BDC:NH2-BDC = 5:5 nanoparticle compatibilizer were blended. The mixture was added to a Hacker torque rheometer for blending at 180°C, 60 rpm, and 8 min. The resulting sample was then molded into a sheet using a tablet press at 180°C, and tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties of the specimens were determined using a universal testing machine. Simultaneously, the low-temperature brittle and tensile fracture surfaces of the specimens were observed using a cold field emission scanning electron microscope. The relevant mechanical property parameters are shown in Table 1, and the stress-strain curves are shown in... Figure 1 As shown, the tensile fracture morphology and the low-temperature brittle fracture morphology are respectively as follows: Figure 2 , Figure 3 As shown.

[0033] Example 2

[0034] First, nanoparticles with a ligand ratio of BDC:NH2-BDC = 0:10 were prepared. 0.0892 g and 0.375 mmol of NiCl2·6H2O, 0.0893 g and 0.375 mmol of CoCl2·6H2O, and 0.1359 g and 0.750 mmol of 2-aminoterephthalic acid (NH2-BDC) were weighed. These three reagents were dissolved together in a mixed solution consisting of 32 ml dimethylformamide (DMF), 2 ml ethanol, and 2 ml deionized water. After complete dissolution, 0.8 ml of triethylamine was added to the solution, and the solution was sonicated in an ultrasonic bath for 1 hour. After sonication, stirring was continued at room temperature for 5.5 hours. The resulting solution was centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. The precipitate was then washed with 15 ml of ethanol, centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. This process was repeated three times. Finally, the precipitate was dried in a vacuum oven at 60°C for 12 hours to prepare nanoparticles with a BDC:NH2-BDC ratio of 0:10. Subsequently, 35.0 g of polylactic acid resin (4032D, from Natureworks, USA), 15 g of polybutylene succinate (TH801, from Xinjiang Lanshan Tunhe Chemical Co., Ltd.), and 0.05 g of nanoparticles with only NH2-BDC ligand were blended. The mixture was added to a Hacker torque rheometer for blending at 180°C, 60 rpm, and 8 min. The resulting sample was then molded into a sheet using a tablet press at 180°C. Tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties were measured using an electronic universal testing machine. The relevant parameters are shown in Table 1, and the stress-strain curves are shown in Table 2. Figure 1 As shown.

[0035] Example 3

[0036] First, nanoparticles with a ligand ratio of BDC:NH2-BDC = 2:8 were prepared. 0.0892 g and 0.375 mmol of NiCl2·6H2O, 0.0893 g and 0.375 mmol of CoCl2·6H2O, 0.0249 g and 0.150 mmol of terephthalic acid (BDC), and 0.1087 g and 0.600 mmol of 2-aminoterephthalic acid (NH2-BDC) were weighed. These four reagents were dissolved together in a mixed solution consisting of 32 ml dimethylformamide (DMF), 2 ml ethanol, and 2 ml deionized water. After complete dissolution, 0.8 ml of triethylamine was added to the solution, and the solution was sonicated in an ultrasonic bath for 1 hour. After sonication, stirring was continued at room temperature for 5.5 hours. The resulting solution was centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. The precipitate was then washed with 15 ml of ethanol, centrifuged at 8000 rpm for 3 min, and the supernatant ethanol was discarded. This process was repeated three times. Finally, the precipitate was dried in a vacuum oven at 60°C for 12 h to prepare BDC:NH2-BDC = 2:8 nanoparticles. Subsequently, 35.0 g of polylactic acid resin (4032D, from Natureworks, USA), 15 g of polybutylene succinate (TH801, from Xinjiang Lanshan Tunhe Chemical Co., Ltd.), and 0.05 g of the nanoparticle compatibilizer with a ligand ratio of BDC:NH2-BDC = 2:8 were blended. The mixture was then added to a Hacker torque rheometer for blending at 180°C, 60 rpm, and for 8 min. The resulting sample was then molded into a sheet using a tablet press at 180°C, and tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties were determined using an electronic universal testing machine. The relevant mechanical property parameters are shown in Table 1, and the stress-strain curves are shown in... Figure 1 As shown.

[0037] Example 4

[0038] First, nanoparticles with a ligand ratio of BDC:NH2-BDC = 8:2 were prepared. 0.0892 g and 0.375 mmol of NiCl2·6H2O, 0.0893 g and 0.375 mmol of CoCl2·6H2O, 0.0997 g and 0.600 mmol of terephthalic acid (BDC), and 0.0272 g and 0.150 mmol of 2-aminoterephthalic acid (NH2-BDC) were weighed. These four reagents were dissolved together in a mixed solution consisting of 32 ml dimethylformamide (DMF), 2 ml ethanol, and 2 ml deionized water. After complete dissolution, 0.8 ml of triethylamine was added to the solution, and the solution was sonicated in an ultrasonic bath for 1 hour. After sonication, stirring was continued at room temperature for 5.5 hours. The resulting solution was centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. The precipitate was then washed with 15 ml of ethanol, centrifuged at 8000 rpm for 3 min, and the supernatant ethanol was discarded. This process was repeated three times. Finally, the precipitate was dried in a vacuum oven at 60°C for 12 h to prepare BDC:NH2-BDC = 8:2 nanoparticles. Subsequently, 35.0 g of polylactic acid resin (4032D, from Natureworks, USA), 15 g of polybutylene succinate (TH801, from Xinjiang Lanshan Tunhe Chemical Co., Ltd.), and 0.05 g of the nanoparticle compatibilizer with a ligand ratio of BDC:NH2-BDC = 8:2 were blended. The mixture was then added to a Hacker torque rheometer for blending at 180°C, 60 rpm, and for 8 min. The resulting sample was then molded into a sheet using a tablet press at 180°C, and tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties were determined using an electronic universal testing machine. The relevant mechanical property parameters are shown in Table 1, and the stress-strain curves are shown in... Figure 1 As shown.

[0039] Example 5

[0040] First, metal framework nanoparticles with BDC as the ligand were prepared by weighing 0.0892 g and 0.375 mmol of NiCl₂·6H₂O, 0.0893 g and 0.375 mmol of CoCl₂·6H₂O, and 0.1246 g and 0.750 mmol of terephthalic acid (BDC). These three reagents were dissolved together in a mixed solution consisting of 32 ml of dimethylformamide (DMF), 2 ml of ethanol, and 2 ml of deionized water. After complete dissolution, 0.8 ml of triethylamine was added to the solution, and the solution was sonicated in an ultrasonic bath for 1 hour. After sonication, the mixture was stirred for another 5.5 hours at room temperature. The resulting solution was centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. The precipitate was then washed with 15 ml of ethanol, centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. This process was repeated three times. Finally, the precipitate was dried in a vacuum oven at 60°C for 12 hours to prepare metal framework nanoparticles with BDC as the ligand. Subsequently, 35.0 g of polylactic acid resin (4032D, from Natureworks, USA), 15 g of polybutylene succinate (TH801, from Xinjiang Lanshan Tunhe Chemical Co., Ltd.), and 0.05 g of BDC-only nanoparticle compatibilizer were blended. The mixture was added to a Hacker torque rheometer for blending at 180°C, 60 rpm, and 8 min. The resulting sample was then molded into a sheet using a tablet press at 180°C. Tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties were measured using an electronic universal testing machine. The relevant parameters are shown in Table 1, and the stress-strain curves are shown in Table 2. Figure 1 As shown.

[0041] Example 6

[0042] First, nanoparticles with a ligand ratio of BDC:NH2-BDC = 5:5 were prepared. 0.0892 g and 0.375 mmol of NiCl2·6H2O, 0.0893 g and 0.375 mmol of CoCl2·6H2O, 0.0623 g and 0.375 mmol of terephthalic acid (BDC), and 0.0679 g and 0.375 mmol of 2-aminoterephthalic acid (NH2-BDC) were weighed. These four reagents were dissolved together in a mixed solution consisting of 32 ml dimethylformamide (DMF), 2 ml ethanol, and 2 ml deionized water. After complete dissolution, 0.8 ml of triethylamine was added to the solution, and the solution was sonicated in an ultrasonic bath for 1 hour. After sonication, stirring was continued at room temperature for 5.5 hours. The resulting solution was centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. The precipitate was then washed with 15 ml of ethanol, centrifuged at 8000 rpm for 3 min, and the supernatant ethanol was discarded. This process was repeated three times. Finally, the precipitate was dried in a vacuum oven at 60 °C for 12 h to prepare BDC:NH2-BDC = 5:5 nanoparticles. Subsequently, 35.0 g of polylactic acid resin (4032D, from Natureworks, USA), 15 g of polybutylene succinate (TH801, from Xinjiang Lanshan Tunhe Chemical Co., Ltd.), and 0.15 g of the BDC:NH2-BDC = 5:5 ligand compatibilizer were blended. The mixture was added to a Hacker torque rheometer for blending at 180 °C, 60 rpm, and 8 min. The resulting sample was then molded into a sheet using a tablet press at 180 °C. Tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties were measured using an electronic universal testing machine, and the relevant parameters are shown in Table 1.

[0043] Example 7

[0044] First, nanoparticles with a ligand ratio of BDC:NH2-BDC = 5:5 were prepared. 0.0892 g and 0.375 mmol of NiCl2·6H2O, 0.0893 g and 0.375 mmol of CoCl2·6H2O, 0.0623 g and 0.375 mmol of terephthalic acid (BDC), and 0.0679 g and 0.375 mmol of 2-aminoterephthalic acid (NH2-BDC) were weighed. These four reagents were dissolved together in a mixed solution consisting of 32 ml dimethylformamide (DMF), 2 ml ethanol, and 2 ml deionized water. After complete dissolution, 0.8 ml of triethylamine was added to the solution, and the solution was sonicated in an ultrasonic bath for 1 hour. After sonication, stirring was continued at room temperature for 5.5 hours. The resulting solution was centrifuged at 8000 rpm for 3 minutes, and the supernatant was discarded. The precipitate was then washed with 15 ml of ethanol, centrifuged at 8000 rpm for 3 min, and the supernatant ethanol was discarded. This process was repeated three times. Finally, the precipitate was dried in a vacuum oven at 60 °C for 12 h to prepare BDC:NH2-BDC = 5:5 nanoparticles. Subsequently, 35.0 g of polylactic acid resin (4032D, from Natureworks, USA), 15 g of polybutylene succinate (TH801, from Xinjiang Lanshan Tunhe Chemical Co., Ltd.), and 0.25 g of nanoparticle compatibilizer with a ligand ratio of BDC:NH2-BDC = 5:5 were blended. The mixture was added to a Hacker torque rheometer for blending at 180 °C, 60 rpm, and 8 min. The resulting sample was then molded into a sheet using a tablet press at 180 °C. Tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties were measured using an electronic universal testing machine, and the relevant parameters are shown in Table 1.

[0045] Example 8

[0046] First, nanoparticles with a ligand ratio of BDC:NH2-BDC = 5:5 were prepared. 0.0892 g and 0.375 mmol of NiCl2·6H2O, 0.0893 g and 0.375 mmol of CoCl2·6H2O, 0.0623 g and 0.375 mmol of terephthalic acid (BDC), and 0.0679 g and 0.375 mmol of 2-aminoterephthalic acid (NH2-BDC) were weighed. These four reagents were dissolved together in a mixed solution consisting of 32 ml dimethylformamide (DMF), 2 ml ethanol, and 2 ml deionized water. After complete dissolution, 0.8 ml of triethylamine was added to the solution, and the solution was sonicated in an ultrasonic bath for 1 hour. After sonication, stirring was continued at room temperature for 5.5 hours. After stirring, the solution was washed three times with ethanol, and the resulting solution was centrifuged at 8000 rpm for 3 minutes. The supernatant was then discarded. The precipitate was then washed with 15 ml of ethanol, centrifuged at 8000 rpm for 3 min, and the supernatant ethanol was discarded. This process was repeated three times. Finally, the precipitate was dried in a vacuum oven at 60 °C for 12 h to prepare BDC:NH2-BDC = 5:5 nanoparticles. Subsequently, 35.0 g of polylactic acid resin (4032D, from Natureworks, USA) and 15 g of polycaprolactone (CAPA 6500, from Perstorp, Sweden) were blended. The mixture was added to a Hacker torque rheometer for blending at 180 °C, 60 rpm, and 8 min. The resulting sample was then molded into a sheet at 180 °C using a tablet press. Tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties were measured using an electronic universal testing machine. The relevant mechanical property parameters are shown in Table 1, and the stress-strain curves are shown in Table 2. Figure 6 As shown.

[0047] Comparative Example 1

[0048] 35.0 g of polylactic acid resin (4032D, from Natureworks, USA) and 15 g of polybutylene succinate (TH801, from Xinjiang Lanshan Tunhe Chemical Co., Ltd.) were blended. The mixture was then added to a Hacker torque rheometer for blending at 180℃, 60 rpm, and 8 min. The resulting sample was then molded into a sheet using a tablet press at 180℃. Tensile specimens were obtained by cutting the sheet using a sample preparation machine. The mechanical properties of the specimens were measured using a universal testing machine. Simultaneously, the low-temperature brittle fracture surface and tensile fracture surface morphology of the specimens were observed using a cold field emission scanning electron microscope. The relevant mechanical property parameters are shown in Table 1, and the stress-strain curves are shown in Table 2. Figure 1 As shown, the tensile fracture morphology and the low-temperature brittle fracture morphology are respectively as follows: Figure 4 , Figure 5 As shown.

[0049] Comparative Example 2

[0050] 35.0 g of polylactic acid resin (4032D, from Natureworks, USA) and 15 g of polycaprolactone (CAPA6500, from Perstorp, Sweden) were blended. The mixture was then added to a Hacker torque rheometer for blending at 180 °C, 60 rpm, and 8 min. The resulting material was then molded into sheet samples using a tablet press at 180 °C. Tensile specimens were obtained by cutting the sheets using a sample preparation machine. The mechanical properties of the specimens were measured using a universal testing machine. Simultaneously, the low-temperature brittle fracture surface and tensile fracture surface morphology of the specimens were observed using a cold field emission scanning electron microscope. The relevant mechanical property parameters are shown in Table 1, and the stress-strain curves are shown in Table 2. Figure 6 As shown.

[0051] Table 1

[0052] Comparative Example 1 48±2.0 944±5.8 43±3.5 9±1.0 Comparative Example 2 34±1.3 858±63.8 31±7.3 7±0.4 Example 1 53±0.8 1096±78.4 42±10.8 265±13.9 Example 2 50±1.3 1029±30.3 15±10.7 48±1.3 Example 3 52±1.0 1038±32.8 19±8.8 137±1.0 Example 4 47±7.0 1026±82.7 33±1.3 196±7.0 Example 5 49±1.5 1026±13.7 15±1.1 35±1.5 Example 6 52±1.0 1062±40.3 17±0.5 229±15.2 Example 7 49±1.4 975±17.0 15±0.7 140±16.1 Example 8 35±2.4 919±40.9 18±6.8 8±1.2

[0053] Depend on Figure 1 As shown in Table 1, with the same nanoparticle filler content, different organic ligand ratios also affect the compatibilization effect. With a filler content of 0.1 wt%, adding nanoparticles with a ligand ratio of BDC:NH2-BDC = 5:5 to the blend resulted in the best compatibilization effect. Compared to the component without nanoparticles, the elongation at break increased by 280%, Young's modulus increased by 16%, and tensile strength increased by 10%.

[0054] Depend on Figure 3 and Figure 5 The comparison shows that adding amphiphilic metal-organic framework nanoparticles to the polylactic acid (PLA) / blend system reduces the phase domains of the polybutylene succinate (PBS) dispersed phase, decreases the gap between the two phases in the blend, and improves the compatibility of the blend. This is because the nanoparticles dispersed at the interface provide a certain interfacial adhesion, and the amino functional groups in the organic ligands of the nanoparticles can form hydrogen bonds with the carbonyl groups of PBS, jointly promoting the interaction between PLA and PBS. Figure 2 and Figure 4 It can be seen that under stress, almost all of the polybutylene succinate phase is pulled out, and the stress is effectively transferred from the polylactic acid phase to the polybutylene succinate phase, forming fibers. Table 1 also shows that with the addition of nanoparticles, both Young's modulus and tensile strength are improved, with a significant increase in elongation at break, indicating that the mechanical properties of the blend are improved. Overall, the polylactic acid / polybutylene succinate composite material prepared using this method exhibits good mechanical properties, and the added filler content is relatively small, showing a significant advantage in compatibility compared to blends modified with traditional compatibilizers.

[0055] The article uses specific examples to illustrate the principles and implementation methods of the present invention, but the implementation methods 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 should be considered equivalent substitutions and are included within the protection scope of the present invention.

Claims

1. An amphiphilic metal-organic framework nanoparticle, characterized in that... The amphiphilic metal-organic framework nanoparticles were prepared using the following method: Metal salts and ligands were dissolved in a mixed solvent of dimethylformamide, ethanol and deionized water, and triethylamine was added. The mixture was sonicated for 1-2 hours to nucleate, and stirred at room temperature for 4-6 hours. The resulting reaction solution was post-treated to obtain amphiphilic metal-organic framework nanoparticles. The molar ratio of the metal salt to the ligand is 1:1 to 1.1, and the metal salt is a mixture of nickel salt and cobalt salt, with a molar ratio of nickel salt to cobalt salt of 1:1 to 1.05; the ligand is a mixture of terephthalic acid and 2-aminoterephthalic acid, with a molar ratio of terephthalic acid to the ligand of 2-8:10; the molar ratio of triethylamine to the ligand is 1:7.6 to 9.

5.

2. The amphiphilic metal-organic framework nanoparticles as described in claim 1, characterized in that: The nickel salt is nickel chloride or nickel sulfate, and the cobalt salt is cobalt chloride or cobalt sulfate.

3. The amphiphilic metal-organic framework nanoparticles as described in claim 1, characterized in that: The mixed solvent is composed of dimethylformamide, ethanol and deionized water in a volume ratio of 32:2~5:2~5.

4. The amphiphilic metal-organic framework nanoparticles as described in claim 1, characterized in that: The post-processing is as follows: the reaction solution is centrifuged, the resulting precipitate is washed with ethanol by centrifugation, and dried to obtain the amphiphilic metal-organic framework nanoparticles.

5. The application of the amphiphilic metal-organic framework nanoparticles as described in claim 1 in compatibilizing incompatible blends; wherein the incompatible blends comprise polymer A and polymer B, wherein polymer A is polylactic acid and polymer B is an aliphatic polyester plastic.

6. The application as described in claim 5, characterized in that: The polymer B is one or both of polybutylene succinate and polycaprolactone.

7. The application as described in claim 5, characterized in that: Incompatible polymers A and B and the aforementioned amphiphilic metal-organic framework nanoparticles are melt-blended and molded to obtain a blend; the mass of polymer A is 50-70% of the total mass of polymers A and B; the mass of the amphiphilic metal-organic framework nanoparticles is 0.1-0.5% of the total mass of polymers A and B.

8. The application as described in claim 5, characterized in that: Polymer A is polylactic acid, polymer B is polybutylene succinate, the mass of polymer A is 70% of the total mass of polymer A and polymer B, and the mass of the amphiphilic metal-organic framework nanoparticles is 0.1% of the total mass of polymer A and polymer B.

9. The application as described in claim 7, characterized in that: The equipment used for melt blending was a Hacker torque rheometer, the blending temperature was 180℃, the blending speed was 60 rpm, and the blending time was 8 min.

10. The application as described in claim 7, characterized in that: The molding temperature is 180℃, the pre-compression pressure is 4MPa, the pre-compression time is 1min, the holding pressure is 10MPa, and the holding time is 2min.

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