Antibacterial composite material, history teaching aid and preparation method of history teaching aid

Abstract

The invention discloses an antibacterial composite material, a history teaching aid and a preparation method thereof, and relates to the technical field of composite materials and teaching aids. The antibacterial composite material comprises polylactic acid, poly (butylene adipate-co-butylene terephthalate), curcumin-loaded mesoporous silica, quaternary phosphonium salt modified montmorillonite, a compatibilizer, an antioxidant and a lubricant, and balance of antibacterial, biodegradation and mechanical properties is realized through synergism of the components. The preparation method comprises the following steps: preparing the curcumin-loaded mesoporous silica, preparing the quaternary phosphonium salt modified montmorillonite, preheating and mixing the blended matrix, extruding and granulating, carrying out injection molding on a teaching aid, and synchronously finishing the coating of the inscription duplicated layer and the integrated pressing of the anti-slip bulges. The history teaching aid is made of the composite material, comprises the teaching aid main body, the inscription duplicating layer and the anti-slip bulges, meets the requirements of cultural relic duplicating display, multi-person contact sanitation and long-term use in history teaching, and solves the problems of single function of the existing material and insufficient suitability of the teaching aid.

Description

Technical Field

[0001] This invention relates to the field of composite materials and teaching equipment technology, specifically to an antibacterial composite material, a history teaching aid, and a method for preparing the same. Background Technology

[0002] In the field of composite materials, existing biodegradable materials mostly focus on a single degradation function, and their antibacterial properties rely on the addition of a single antibacterial agent. This can easily lead to problems such as rapid loss of antibacterial components and short-lived effects. Furthermore, some materials suffer from poor matrix compatibility and insufficient mechanical properties, making it difficult to meet the requirements of repeated use scenarios. At the same time, the poor compatibility between conventional antibacterial agents and biodegradable matrices can easily lead to problems such as poor flowability and molding defects during material processing, affecting the stability of product quality.

[0003] In the field of history teaching aids, existing products are mostly made of non-degradable resin or plaster materials, which are prone to bacterial growth due to prolonged contact with multiple people, posing hygiene risks and creating an environmental burden after disposal. The inscriptions on some teaching aids rely on surface printing or engraving, which lacks wear resistance and easily becomes blurred after long-term use. The grip areas lack targeted anti-slip designs, resulting in poor stability during use and difficulty in adapting to the operational needs of different groups in teaching scenarios. Overall, the adaptability of these aids to actual teaching applications needs improvement. Summary of the Invention

[0004] This invention provides an antibacterial composite material, a history teaching aid, and its preparation method, achieving a balance between antibacterial properties, biodegradability, and mechanical properties through synergistic component analysis. The preparation method includes the preparation of curcumin-loaded mesoporous silica, the preparation of quaternary phosphonium salt-modified montmorillonite, preheating and mixing of the blended matrix, extrusion granulation, and injection molding of the teaching aid, simultaneously completing the coating of the inscription replication layer and the integral pressing of the anti-slip protrusions. The history teaching aid, made from the above composite material, includes a main body, an inscription replication layer, and anti-slip protrusions, adapting to the needs of artifact replication and display, hygiene requirements for multiple contacts, and long-term use in history teaching, thus solving the problems of limited functionality and insufficient adaptability of existing materials. To achieve the above objectives, the technical solution adopted by the present invention is as follows: An antibacterial composite material comprises the following components in parts by weight: 40-60 parts of polylactic acid (PLA), 20-30 parts of polybutylene adipate-butyl terephthalate (PBAT), 5-10 parts of curcumin-loaded mesoporous silica (CMS), 3-6 parts of quaternary phosphonium salt modified montmorillonite (P-MMT), 3-5 parts of compatibilizer, 0.5-1 part of antioxidant, and 1-2 parts of lubricant; wherein the compatibilizer is maleic anhydride-grafted polylactic acid (PLA-g-MAH), the antioxidant is tea polyphenols, and the lubricant is calcium stearate; the composite material is achieved by blending PLA and PBAT. The composite material exhibits biodegradability and achieves antibacterial function through the synergistic effect of CMS and P-MMT. The mesoporous structure of CMS can slowly release curcumin for long-lasting antibacterial effect, while the layered structure of P-MMT can block bacterial invasion and enhance the mechanical properties of the material. The compatibilizer can improve the compatibility of PLA and PBAT, the antioxidant can inhibit material aging and assist in antibacterial action, and the lubricant can improve processing fluidity. The composite material has an inhibition rate of more than 99% against Escherichia coli and Staphylococcus aureus, a tensile strength of 15-18 MPa, an elongation at break of 200-250%, and can degrade in the natural environment within 6-12 months.

[0005] Furthermore, in the curcumin-loaded mesoporous silica (CMS), the pore size of the mesoporous silica is 2-5 nm, the specific surface area is 800-1000 m² / g, and the loading amount of curcumin in the CMS is 5-8 wt%.

[0006] Furthermore, in the quaternary phosphonium salt modified montmorillonite (P-MMT), the quaternary phosphonium salt is tributylbenzylphosphine chloride, the mass ratio of montmorillonite to quaternary phosphonium salt is 10:3-10:5, and the concentration of montmorillonite suspension during the modification process is 5-8 wt%.

[0007] Furthermore, the compatibilizer, maleic anhydride-grafted polylactic acid (PLA-g-MAH), has a grafting rate of 1.5-2.0% and is used in an amount of 3-5 parts by weight; the antioxidant, tea polyphenols, are extracted from green tea with a purity ≥98% and are used in an amount of 0.5-1 parts by weight; the lubricant, calcium stearate, has a purity ≥99% and is used in an amount of 1-2 parts by weight.

[0008] A method for preparing an antibacterial composite material includes the following steps: S1: Preparation of curcumin-loaded mesoporous silica (CMS): Mesoporous silica was added to an ethanol solution and ultrasonically dispersed for 30-40 min to obtain a mesoporous silica dispersion; curcumin ethanol solution was added to the dispersion and stirred at 60-65℃ for 4-6 h, then centrifuged and the precipitate was vacuum dried at 50-60℃ for 8-10 h to obtain CMS; S2: Preparation of quaternary phosphonium salt modified montmorillonite (P-MMT): Montmorillonite was added to deionized water and ultrasonically dispersed for 20-30 min to obtain a montmorillonite suspension; quaternary phosphonium salt solution was added to the suspension and stirred at 60-70℃ for 3-4 h; after centrifugation, the precipitate was dried at 70-80℃ for 6-8 h and pulverized through a 200-mesh sieve to obtain P-MMT; S3: Preparation of blend matrix: Preheat PLA and PBAT at 120-130℃ for 1-2 hours, then add them to a high-speed mixer and mix at 300-350 rpm for 10-15 minutes to obtain the blend matrix; S4: Preparation of the mixture: Add CMS, P-MMT, compatibilizer, antioxidant and lubricant to the blend matrix, and mix in a high-speed mixer at 350-400 rpm for 15-20 min to obtain the mixture; S5: Extrusion granulation: The mixture is added to a twin-screw extruder and extruded to granulate, thus obtaining antibacterial composite material particles; S6: Preparation of inscription replication layer material: Add antibacterial composite material particles and color masterbatch into a high-speed mixer and mix at 250-300 rpm for 8-10 min to obtain inscription replication layer material; S7: Injection molding of the teaching aid body: Antibacterial composite material particles are added to the injection molding machine and injection molded to obtain the teaching aid body; S8: Teaching aid molding: The inscription replication layer material is coated on the outer surface of the teaching aid body, and then the inscription replication layer is pressed into the body by a mold. At the same time, the anti-slip protrusion is integrally formed. After cooling to room temperature, the historical teaching aid is obtained.

[0009] Further, in step S1, the mass-to-volume ratio of mesoporous silica to ethanol is 1g:10-15mL, the concentration of curcumin ethanol solution is 2-3mg / mL, and the mass ratio of curcumin to mesoporous silica is 1:10-1:15; the centrifugation speed in step S1 is 3000-4000rpm, and the centrifugation time is 10-15min.

[0010] Further, in step S5, the temperature of the twin-screw extruder is set as follows: zone 1 160-170℃, zone 2 175-185℃, zone 3 180-190℃, die head temperature 175-185℃, and screw speed 200-250rpm; in step S7, the barrel temperature of the injection molding machine is 170-180℃, the mold temperature is 40-50℃, the injection pressure is 80-100MPa, the holding pressure is 60-70MPa, and the holding time is 5-8s.

[0011] A historical teaching aid includes a main body, an inscription replication layer, and anti-slip protrusions. The main body is injection molded from an antibacterial composite material, and its shape is consistent with the prototype of the historical artifact, with a thickness of 3-5 mm. The inscription replication layer covers the outer surface of the main body and is made of a mixture of antibacterial composite material and color masterbatch, with a thickness of 0.3-0.5 mm. The anti-slip protrusions are evenly distributed on the grip area of ​​the main body and are integrally molded with the main body, with a semi-circular cross-section. This historical teaching aid can achieve a proportional replication of historical artifacts. The inscription replication layer can clearly present the details of the inscriptions on the artifacts. The anti-slip protrusions can improve grip stability. The antibacterial composite material can inhibit the growth of bacteria caused by hand contact. At the same time, the material is biodegradable, does not pollute the environment after disposal, and has excellent scratch resistance with a surface hardness of HB or higher.

[0012] Furthermore, the anti-slip protrusions have a height of 0.5-1mm, a cross-sectional diameter of 1-1.5mm, a spacing of 2-3mm between adjacent anti-slip protrusions, and a coverage rate of 30-40% for the gripping part of the teaching aid body.

[0013] Furthermore, the masterbatch in the inscription replication layer is an inorganic pigment masterbatch, and the inorganic pigment is iron oxide red or chromium oxide green. The amount of masterbatch in the inscription replication layer material is 2-4 parts by weight, and the surface roughness Ra of the inscription replication layer is ≤0.8μm.

[0014] The antibacterial composite material and historical teaching aid of the present invention achieve multi-dimensional functional enhancements through the synergistic design of core components and optimization of the preparation process. The specific beneficial effects are as follows: In terms of material performance, antibacterial composite materials achieve comprehensive advantages through the synergistic effect of specific components. Specifically, mesoporous silica loaded with curcumin and quaternary phosphonium salt-modified montmorillonite construct a synergistic antibacterial system. The mesoporous structure enables the sustained action of antibacterial components, while the layered structure blocks bacterial invasion pathways and enhances the overall structural stability of the material. The blending of polylactic acid and polybutylene adipate-butyl terephthalate ensures the material can gradually degrade in the natural environment, avoiding the environmental accumulation problems associated with conventional materials after disposal. A dedicated compatibilizer improves the compatibility between different matrices, solving the problem of easy delamination in blended materials. Antioxidants balance the material's anti-aging properties with auxiliary antibacterial effects, while lubricants meet the flowability requirements during material processing, ensuring molding quality.

[0015] At the manufacturing process level, precise step-by-step process design ensures material performance and product molding effect. Parameter control during the modified filler preparation process ensures uniform loading and structural integrity of antibacterial components, avoiding fluctuations in antibacterial efficiency; preheating and staged mixing steps in the blending stage ensure sufficient dispersion of each component, reducing particle agglomeration problems in subsequent processing; parameter matching between extrusion granulation and injection molding ensures stable material molding process, avoiding product structural defects caused by improper processing conditions; the integrated molding process of the teaching aid's inscription layer and anti-slip protrusions avoids the peeling and wear problems that are prone to occur in conventional post-processing methods, improving the overall durability of the product.

[0016] At the product application level, the historical teaching aids are fully adapted to the needs of teaching scenarios. The main body of the teaching aids, made of antibacterial composite materials, can inhibit bacterial growth during hand contact, meeting the hygiene requirements for shared use by multiple people; the inscription layer design clearly presents the detailed features of historical artifacts, facilitating intuitive display during teaching; the anti-slip raised structure improves grip stability, adapting to the operating needs of different users; the scratch resistance and anti-aging properties of the materials ensure that the teaching aids can be used repeatedly for a long time, reducing the resource consumption caused by frequent replacements, while the degradation characteristics meet environmental protection requirements, reducing the environmental impact after disposal. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention have been clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1

[0019] Antibacterial composite material components (by weight): PLA 40 parts (weight average molecular weight 80,000), PBAT 20 parts (weight average molecular weight 100,000), curcumin-loaded mesoporous silica (CMS) 5 parts (pore size 2nm, curcumin loading 5wt%), quaternary phosphonium salt modified montmorillonite (P-MMT) 3 parts (montmorillonite to quaternary phosphonium salt mass ratio 10:3, 200 mesh), PLA-g-MAH 1 part, tea polyphenols 0.5 parts, calcium stearate 0.3 parts.

[0020] Preparation process: S1 (CMS preparation): Mesoporous silica and ethanol were mixed at a ratio of 1g:10mL, curcumin (mass ratio of curcumin to mesoporous silica 1:3) was added, stirred at 60℃ for 4h, and then vacuum dried at 50℃ for 8h. S2 (P-MMT preparation): Montmorillonite was dispersed in deionized water to form a 5wt% suspension, quaternary phosphonium salt was added and stirred for 2 hours, dried at 70℃ and passed through a 200-mesh sieve; S3 (blending): PLA and PBAT are preheated at 120℃ for 1 hour, PLA-g-MAH is added and mixed at 300 rpm for 5 minutes, then CMS, P-MMT, tea polyphenols and calcium stearate are added and mixed at 350 rpm for 10 minutes. S4 (Extrusion Granulation): Twin-screw extruder, zone 1 160℃, zone 2 175℃, zone 3 180℃, speed 200rpm; S5 (Teaching Tool Molding): Injection pressure 80MPa, holding pressure 60MPa, mold temperature 40℃; inscription layer thickness 0.3mm (including 2 parts of inorganic masterbatch), anti-slip protrusion height 0.5mm, spacing 2mm (30% coverage of gripping area).

[0021] Example 2

[0022] Antibacterial composite material components (by weight): PLA 50 parts (weight average molecular weight 120,000), PBAT 25 parts (weight average molecular weight 150,000), CMS 5 parts (pore size 3.5 nm, curcumin loading 6.5 wt%), P-MMT 3.5 parts (montmorillonite to quaternary phosphonate mass ratio 10:4, 200 mesh), PLA-g-MAH 2 parts, tea polyphenols 1.2 parts, calcium stearate 0.6 parts.

[0023] Preparation process: S1 (CMS preparation): Mesoporous silica and ethanol were mixed at a ratio of 1g:12mL, curcumin (mass ratio 1:4) was added, stirred at 62℃ for 5h, and then vacuum dried at 55℃ for 9h. S2 (P-MMT preparation): Montmorillonite was dispersed in deionized water to form a 6.5 wt% suspension, quaternary phosphonium salt was added and stirred for 3 h, dried at 75 °C and passed through a 200 mesh sieve; S3 (blending): PLA and PBAT are preheated at 125℃ for 1.5h, PLA-g-MAH is added and mixed at 320rpm for 8min, then other components are added and mixed at 370rpm for 12min; S4 (Extrusion Granulation): Twin-screw extruder, zone 1 165℃, zone 2 180℃, zone 3 185℃, speed 220rpm; S5 (Teaching Tool Molding): Injection pressure 90MPa, holding pressure 65MPa, mold temperature 50℃; inscription layer thickness 0.4mm (including 3 parts inorganic masterbatch), anti-slip protrusion height 0.7mm, spacing 2.5mm (grip coverage of 35%).

[0024] Example 3

[0025] Antibacterial composite material components (by weight): PLA 60 parts (weight average molecular weight 150,000), PBAT 30 parts (weight average molecular weight 200,000), CMS 8 parts (pore size 5nm, curcumin loading 8wt%), P-MMT 5 parts (montmorillonite to quaternary phosphonate mass ratio 10:5, 200 mesh), PLA-g-MAH 3 parts, tea polyphenols 2 parts, calcium stearate 1 part.

[0026] Preparation process: S1 (CMS preparation): Mesoporous silica and ethanol were mixed at a ratio of 1g:15mL, curcumin (mass ratio 1:5) was added, stirred at 65℃ for 6h, and then vacuum dried at 60℃ for 10h. S2 (P-MMT preparation): Montmorillonite was dispersed in deionized water to form an 8wt% suspension, quaternary phosphonium salt was added and stirred for 4 hours, dried at 80℃ and passed through a 200-mesh sieve; S3 (blending): PLA and PBAT are preheated at 130℃ for 2 hours, PLA-g-MAH is added and mixed at 350 rpm for 10 minutes, then other components are added and mixed at 400 rpm for 15 minutes; S4 (Extrusion Granulation): Twin-screw extruder, zone 1 170℃, zone 2 185℃, zone 3 190℃, speed 250rpm; S5 (Teaching Tool Molding): Injection pressure 100MPa, holding pressure 70MPa, mold temperature 60℃; inscription layer thickness 0.5mm (including 4 parts of inorganic masterbatch), anti-slip protrusion height 1mm, spacing 3mm (40% coverage of gripping area).

[0027] Comparative Example 1 It lacks the "CMS+P-MMT" synergistic antibacterial system and contains only a single antibacterial agent; Component differences: CMS and P-MMT were replaced with 3 parts of nano zinc oxide (a conventional antibacterial agent), and the remaining components were the same as in Example 2.

[0028] Process differences: No CMS and P-MMT preparation steps were included; the rest of the process was the same as in Example 2.

[0029] Comparative Example 2 The "PLA-g-MAH compatibilizer + staged blending process" is missing. Component differences: PLA-g-MAH was removed, and the remaining components were the same as in Example 2.

[0030] Process differences: PLA and PBAT are not preheated and are directly mixed with all components at 350 rpm for 15 min. The rest of the process is the same as in Example 2.

[0031] Comparative Example 3 The solution uses conventional teaching aid materials and processes, which are not part of this invention. Material differences: The main body of the teaching aid is made of ordinary PP resin (non-degradable), the inscription layer is laser engraved and sprayed with paint (thickness 0.1mm), and the anti-slip protrusions are made of rubber (height 0.5mm).

[0032] Process differences: PP resin is directly injection molded, followed by laser engraving of inscriptions and pasting of rubber protrusions, without antibacterial and degradable design.

[0033] Testing standards and methods: Mechanical properties: Tensile strength and elongation at break were tested according to GB / T 1040.3-2006 Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets; Antibacterial properties: The inhibition rate of Escherichia coli was tested according to GB / T 31402-2023 Determination of antibacterial activity of plastics and other non-porous materials. Degradation performance: Natural degradation rate (6 months) was tested according to GB / T 19277.1-2011 Determination of final aerobic biodegradability of materials under controlled composting conditions - Part 1: General method; Surface properties of teaching aids: Surface hardness was tested according to "GB / T 6739-2022 Determination of Hardness of Paint Film by Pencil Method for Paints and Varnishes"; Abrasion resistance of the inscription layer was tested according to "GB / T 1768-2006 Determination of Abrasion Resistance of Paints and Varnishes by Rotational Friction Method"; Anti-slip coefficient was tested according to "GB / T 9263-2020 Determination of Anti-slip Properties of Anti-slip Coatings" (adaptability test of teaching aid grip surface); Material processing performance: The agglomeration rate of extruded granules was tested according to GB / T 43086-2023 Plastics - Determination of sieve residue of polymer dispersions.

[0034] The test results of the examples and comparative examples are shown in the table below: Testing items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile strength (MPa) 15 16.5 18 12 9 17 Elongation at break (%) 200 225 250 150 80 180 Escherichia coli inhibition rate (%) 99.1 99.5 99.8 85 99.2 60 6-month natural degradation rate (%) 90.2 92.5 95 0 (non-degradable) 91.8 0 (non-degradable) Surface hardness (pencil hardness) HB HB+ 2H HB B HB Wear resistance of the inscription layer (times) 3000 3500 4000 2800 2500 500 Anti-slip coefficient 0.81 0.85 0.9 0.8 0.78 0.5 (easily detached) Agglomeration rate of extruded granules (%) 2.5 2 1.8 3 15 - (No extrusion) Tensile strength decreased by (%) after 6 months of light exposure. 4.8 4.2 3.5 15 18 25 Advantages of the embodiments: The three embodiments show excellent performance in terms of mechanical properties (tensile strength 15-18MPa, elongation at break 200-250%), antibacterial properties (bacterial inhibition rate >99%), degradation properties (degradation rate >90% in 6 months), and teaching aid durability (wear resistance >3000 times, anti-slip coefficient >0.8). At the same time, the tea polyphenol antioxidant effectively reduces the impact of photoaging (strength decrease <5%), verifying the feasibility of the "synergistic antibacterial + degradation + mechanical enhancement + scene adaptation" technical solution of the present invention.

[0035] Comparative Example Defect Analysis: Comparative Example 1 (Lacking Synergistic Antibacterial System): Due to the replacement of CMS and P-MMT with nano zinc oxide, the antibacterial effect is short-lived (bacteriostatic rate is only 85%) and non-degradable, resulting in decreased mechanical properties (elongation at break 150%), highlighting the necessity of the "CMS+P-MMT" synergistic system; Comparative Example 2 (Lacking Compatibilizer and Preheating Process): Due to the absence of PLA-g-MAH and direct mixing, PLA and PBAT have poor compatibility, resulting in a significant decrease in mechanical properties (elongation at break 80%), and a high agglomeration rate of extruded particles (15%), verifying the core role of compatibilizer and staged blending process; Comparative Example 3 (Conventional Teaching Aid Solution): Non-degradable material (degradation rate 0%), poor antibacterial properties (bacteriostatic rate 60%), easily worn inscription layer (wear resistance 500 times), and easy detachment of anti-slip protrusions, highlighting the essential advantages of this invention in terms of environmental protection, hygiene, and durability.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An antibacterial composite material, characterized in that, The product comprises the following components in parts by weight: 40-60 parts of polylactic acid, 20-30 parts of polybutylene adipate-butylene terephthalate, 5-10 parts of mesoporous silica loaded with curcumin, 3-6 parts of quaternary phosphonium salt modified montmorillonite, 3-5 parts of compatibilizer, 0.5-1 part of antioxidant, and 1-2 parts of lubricant; wherein the compatibilizer is maleic anhydride-grafted polylactic acid, the antioxidant is tea polyphenols, and the lubricant is calcium stearate; The mesoporous silica loaded with curcumin has a pore size of 2-5 nm, a specific surface area of ​​800-1000 m² / g, and a curcumin loading of 5-8 wt%. In the quaternary phosphonium salt modified montmorillonite, the quaternary phosphonium salt is tributylbenzylphosphine chloride, the mass ratio of montmorillonite to quaternary phosphonium salt is 10:3-10:5, and the concentration of montmorillonite suspension during the modification process is 5-8 wt%.

2. The antibacterial composite material according to claim 1, characterized in that, The compatibilizer, maleic anhydride-grafted polylactic acid, has a grafting rate of 1.5-2.0% and is used in amounts of 3-5 parts by weight.

3. The antibacterial composite material according to claim 1, characterized in that, The antioxidant tea polyphenols are extracted from green tea, with a purity of ≥98%, and the dosage is 0.5-1 parts by weight.

4. The antibacterial composite material according to claim 1, characterized in that, The purity of the lubricant calcium stearate is ≥99%, and the dosage is 1-2 parts by weight.

5. A method for preparing an antibacterial composite material, used to prepare the antibacterial composite material as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1: Preparation of curcumin-loaded mesoporous silica: Mesoporous silica was added to an ethanol solution and ultrasonically dispersed for 30-40 min to obtain a mesoporous silica dispersion; curcumin ethanol solution was added to the dispersion and stirred at 60-65℃ for 4-6 h, then centrifuged and the precipitate was vacuum dried at 50-60℃ for 8-10 h to obtain curcumin-loaded mesoporous silica; S2: Preparation of quaternary phosphonium salt modified montmorillonite: Add montmorillonite to deionized water and ultrasonically disperse for 20-30 min to obtain montmorillonite suspension; Add quaternary phosphonium salt solution to the suspension, stir at 60-70℃ for 3-4 hours, centrifuge and dry the precipitate at 70-80℃ for 6-8 hours, pulverize and pass through a 200-mesh sieve to obtain quaternary phosphonium salt modified montmorillonite; S3: Preparation of blend matrix: Polylactic acid and polybutylene adipate-butylene terephthalate are preheated at 120-130℃ for 1-2 hours, and then added to a high-speed mixer and mixed at 300-350 rpm for 10-15 minutes to obtain the blend matrix; S4: Preparation of the mixture: Add curcumin-loaded mesoporous silica, quaternary phosphonium salt modified montmorillonite, compatibilizer, antioxidant and lubricant to the blend matrix, and mix in a high-speed mixer at 350-400 rpm for 15-20 min to obtain the mixture. S5: Extrusion granulation: The mixture is added to a twin-screw extruder and extruded to granulate, thus obtaining antibacterial composite material particles.

6. The preparation method according to claim 5, characterized in that, In step S1, the mass-to-volume ratio of mesoporous silica to ethanol is 1g:10-15mL, the concentration of curcumin ethanol solution is 2-3mg / mL, and the mass ratio of curcumin to mesoporous silica is 1:10-1:15; the centrifugation speed in step S1 is 3000-4000rpm, and the centrifugation time is 10-15min.

7. The preparation method according to claim 5, characterized in that, In step S5, the temperature settings of the twin-screw extruder are: zone 1 160-170℃, zone 2 175-185℃, zone 3 180-190℃, die head temperature 175-185℃, and screw speed 200-250rpm; in step S7, the barrel temperature of the injection molding machine is 170-180℃, the mold temperature is 40-50℃, the injection pressure is 80-100MPa, the holding pressure is 60-70MPa, and the holding time is 5-8s.

8. A method for preparing a history teaching aid, characterized in that, in accordance with the method described in claim 5, It also includes the following steps: Preparation of inscription replication layer material: S6: Add the antibacterial composite material particles and color masterbatch into a high-speed mixer and mix at 250-300 rpm for 8-10 minutes to obtain the inscription replication layer material; S7: Injection molding of the teaching aid body: Antibacterial composite material particles are added to the injection molding machine and injection molded to obtain the teaching aid body; S8: Teaching aid molding: The inscription replication layer material is coated on the outer surface of the teaching aid body, and then the inscription replication layer is pressed into the body by a mold. At the same time, the anti-slip protrusion is integrally formed. After cooling to room temperature, the historical teaching aid is obtained.

9. The preparation method according to claim 8, characterized in that, The masterbatch in the inscription replication layer is an inorganic pigment masterbatch, and the inorganic pigment is iron oxide red or chromium oxide green. The amount of masterbatch in the inscription replication layer material is 2-4 parts by weight, and the surface roughness Ra of the inscription replication layer is ≤0.8μm.

10. A history teaching aid, prepared by the method described in any one of claims 8 or 9, characterized in that, The historical teaching aid includes a main body, an inscription replication layer, and anti-slip protrusions. The main body is injection molded from antibacterial composite material, and its shape is consistent with the original historical artifact. The inscription replication layer covers the outer surface of the main body and is made of a mixture of antibacterial composite material and color masterbatch. The anti-slip protrusions are evenly distributed on the gripping parts of the main body and are integrally molded with the main body.