Rare earth modified polyvinyl chloride antibacterial composite material as well as preparation method and application thereof

Abstract

The invention discloses a rare earth modified polyvinyl chloride antibacterial composite material as well as a preparation method and application thereof, and belongs to the technical field of polymer composite medical materials. The composite material comprises 80-120 parts of polyvinyl chloride resin, 1.5-3 parts of a rare earth compound, 0.8-1.5 parts of a surface modifier, 10-30 parts of a plasticizer, 2-5 parts of a stabilizer and 1-3 parts of a lubricant. The composite material prepared by the invention has excellent antibacterial performance and stable chemical performance, can be applied to the medical apparatus and instruments to enable the medical apparatus and instruments to realize an antibacterial function, and solves the problems that the performance of the apparatus is damaged and the service life of the apparatus is shortened due to the use of a traditional chemical sterilizing agent.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite medical materials, and particularly relates to a rare earth modified polyvinyl chloride antibacterial composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Polyvinyl chloride (PVC), as a widely used thermoplastic resin, has advantages such as good mechanical properties, high chemical stability, and low cost. With its excellent biocompatibility and drug compatibility, it is widely used in medical devices such as syringes, infusion sets, pharmaceutical packaging materials, auxiliary oxygen masks, gloves, and various pipelines in the operating room. However, ordinary polyvinyl chloride materials themselves do not have antibacterial properties and are prone to bacterial growth during use, leading to cross-infection and threatening human health. Traditional antibacterial modification methods usually involve adding chemical sterilants, but chemical sterilants are likely to cause damage to the performance of medical devices and shorten their service life. With the increasingly strict hygiene standards in the medical environment, major medical institutions and medical professional societies have put forward higher requirements for the sterilization control of medical device products during use.

[0003] Due to their unique electronic layer structures, rare earth elements have excellent broad-spectrum antibacterial and antifungal properties, and also have good stability and safety. Combining rare earth elements with polyvinyl chloride is expected to endow medical devices with good antibacterial and antifungal capabilities and effectively solve the problem of microbial growth when traditional polyvinyl chloride is used in medical devices. However, at present, the technology of introducing rare earth elements into polyvinyl chloride materials to prepare high-efficiency antibacterial and performance-stable composite materials still needs to be improved. Especially in solving the uniform dispersion of rare earth elements, the interfacial compatibility with the polyvinyl chloride matrix, and thus giving full play to the antibacterial efficiency of rare earth elements, there is still a large room for improvement and it is difficult to meet the strict requirements of medical devices for material performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a rare earth modified polyvinyl chloride antibacterial composite material, a preparation method thereof, and an application thereof, to prepare a rare earth modified polyvinyl chloride composite material with excellent antibacterial properties and stable chemical properties, which can endow medical devices with self-cleaning ability when applied to medical devices, realize the antibacterial and antifungal function, and solve the problems of damage to the performance of devices and shortening of the service life of devices caused by the use of traditional chemical sterilants.

[0005] To achieve the above purpose, the present invention provides a rare earth modified polyvinyl chloride antibacterial composite material, which comprises the following components in parts by weight:

[0006] 80 - 120 parts of polyvinyl chloride resin, 1.5 - 3 parts of rare earth compound, 0.8 - 1.5 parts of surface modifier, 10 - 30 parts of plasticizer, 2 - 5 parts of stabilizer, and 1 - 3 parts of lubricant.

[0007] Preferably, the rare earth compound is one or more of salts and oxides of lanthanum, and salts and oxides of cerium.

[0008] Preferably, the surface modifier is one or more of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0009] Preferably, the plasticizer is dioctyl phthalate or epoxidized soybean oil; the stabilizer is a calcium-zinc stabilizer; the lubricant is stearic acid or polyethylene wax.

[0010] The present invention also provides a preparation method of the above-mentioned rare earth-modified polyvinyl chloride antibacterial composite material, comprising the following steps:

[0011] Step 1. Pretreatment of rare earth compound: Grind the rare earth compound into nanoscale powder, then mix it with the surface modifier in an organic solvent, and carry out a stirring reaction under nitrogen protection. After the stirring reaction is completed, filter and wash, and vacuum dry at 80-100 °C for 12-24 h to obtain a surface-modified rare earth compound;

[0012] Step 2. Mixing: Add polyvinyl chloride resin, pretreated rare earth compound, plasticizer, stabilizer and lubricant into a high-speed mixer to obtain a uniform mixed material;

[0013] Step 3. Extrusion molding: Add the mixed material into a twin-screw extruder, and carry out melt extrusion in the temperature range of 160-180 °C. After cooling and pelletizing, obtain rare earth-modified polyvinyl chloride antibacterial composite material pellets.

[0014] Preferably, in the step 1, the particle size of the ground rare earth compound is 20-50 nm; the organic solvent is toluene or xylene.

[0015] Preferably, in the step 1, the stirring speed is 300-600 r / min, the stirring temperature is 80-100 °C, and the stirring time is 2-4 h.

[0016] Preferably, in the step 2, the rotation speed of the high-speed mixer is 800-1200 r / min, the mixing temperature is 100-120 °C, and the mixing time is 10-15 minutes.

[0017] Preferably, in the step 3, in the temperature control zone of the twin-screw extruder, the temperature gradually increases from the feeding section to the head. The temperature of the feeding section is 150-160 °C, the temperature of the intermediate melting section is 160-175 °C, the temperature of the homogenizing section and the head is 170-180 °C, and the rotation speed of the twin-screw is 150-300 r / min.

[0018] The present invention also provides application of the rare earth modified polyvinyl chloride antibacterial composite material in the preparation of medical devices.

[0019] The present invention uses polyvinyl chloride resin as the matrix of the composite material to provide the material with basic mechanical properties and molding processing properties. With its own good thermoplasticity, it can melt and flow during the processing, and is convenient to be made into products of various shapes through injection molding, blow molding, extrusion and other processes. The unique electronic layer structure of rare earth elements enables it to destroy the cell membrane of bacteria, inhibit the respiration of bacteria and interfere with the metabolic process of bacteria, and shows a significant inhibitory effect on common bacteria such as Escherichia coli, Staphylococcus aureus, Candida albicans and so on.

[0020] The molecular structure of the surface modifier contains both functional groups that can react chemically with the surface of the rare earth compound and functional groups that can interact with the polyvinyl chloride matrix. By surface treating the rare earth compound, a chemical bond or physical adsorption layer is formed between the rare earth compound and the polyvinyl chloride matrix, which effectively improves the interfacial compatibility between the two, promotes the uniform dispersion of the rare earth compound in the polyvinyl chloride matrix, avoids agglomeration, and thus improves the mechanical properties and processing properties of the composite material. During the processing, the addition of a plasticizer can make polyvinyl chloride easier to melt and plasticize, reduce the processing temperature and energy consumption, and improve the flexibility, impact resistance and cold resistance of the composite material. Polyvinyl chloride is prone to dehydrochlorination during high-temperature processing or long-term use, resulting in deterioration of material properties. The addition of a stabilizer can capture hydrogen chloride, prevent it from further catalyzing degradation reactions, extend the service life of the material, and ensure the stability of the composite material under different environmental conditions. Lubricants can improve the lubricity between polyvinyl chloride molecular chains, help the uniform dispersion and flow of materials, and ensure the molding quality of the composite material.

[0021] Therefore, the present invention provides a rare earth modified polyvinyl chloride antibacterial composite material and a preparation method and application thereof, which have the following beneficial effects:

[0022] (1) Synergy of antibacterial and mechanical properties: By adding rare earth compounds, polyvinyl chloride composites are endowed with excellent antibacterial properties, and have a significant inhibitory effect on common bacteria such as Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate can reach more than 95%, effectively reducing the risk of bacterial growth during use; at the same time, the surface modifier improves the interfacial compatibility between the rare earth compound and the polyvinyl chloride matrix, making the rare earth evenly dispersed, which not only enhances the antibacterial effect, but also avoids the decrease in the mechanical properties of the material caused by rare earth agglomeration. The polyvinyl chloride matrix provides support for the rare earth compound, allowing it to exist stably, and jointly achieves the improvement of antibacterial and mechanical properties.

[0023] (2) Synergistic processing performance: Plasticizers reduce the melting temperature and viscosity of polyvinyl chloride. Acting together with lubricants, they improve the fluidity of the material and reduce energy consumption during processing. Stabilizers inhibit the degradation of polyvinyl chloride during high-temperature processing, ensuring that additives such as plasticizers and lubricants function properly and maintaining the stable processing performance of the composite material.

[0024] (3) Synergistic stability: Stabilizers prevent the degradation of polyvinyl chloride during processing and use, protecting additives such as rare earth compounds and plasticizers from being damaged. The surface modifier enhances the bonding force between components, improves the structural stability of the composite material, extends the service life of the material, and enables it to maintain good performance under different environmental conditions.

[0025] (4) Rare earth compounds themselves have good stability and safety. Compared with traditional chemical sterilizers such as metal ion antibacterial agents and organic antibacterial agents, they do not cause harm to the human body and the environment, meeting the strict requirements for material safety in the medical field.

[0026] The following is a further detailed description of the technical solution of the present invention through examples. Specific embodiments

[0027] The following further elaborates the present invention in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application and are all within the protection scope of the present invention.

[0028] References to "embodiments" in this document mean that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The term "embodiment" appearing at various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0029] Unless otherwise defined, the meanings of the technical terms used in this document are the same as those commonly understood by those skilled in the technical field to which the present application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit the present application.

[0030] Unless otherwise specified in the present invention, the reagents, instruments, equipment, etc. used are all the reagents, instruments and equipment commonly used by those skilled in the art in this field.

[0031] Example 1

[0032] This example provides a preparation method of a rare earth modified polyvinyl chloride antibacterial composite material. 80 parts of polyvinyl chloride resin, 1.5 parts of lanthanum oxide, 0.8 part of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, 10 parts of dioctyl phthalate, 2 parts of calcium-zinc stabilizer, and 1 part of stearic acid are selected as the raw material formula.

[0033] The preparation specifically includes the following steps:

[0034] Step 1. Pretreatment of rare earth compound: Grind lanthanum oxide to a particle size of 20 nm, mix it with N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane in toluene, and stir at a speed of 300 r / min and 80 °C for 2 h under nitrogen protection. After the reaction is completed, filter and wash, and vacuum dry at 80 °C for 12 h to obtain surface-modified lanthanum oxide.

[0035] Step 2. Mixing: Add polyvinyl chloride resin, surface-modified lanthanum oxide, dioctyl phthalate, calcium-zinc stabilizer, and stearic acid to a high-speed mixer, and mix at a speed of 800 r / min and 100 °C for 10 minutes to obtain a uniform mixed material.

[0036] Step 3. Extrusion molding: Add the mixed material to a twin-screw extruder for melting and then extrusion. Among them, the temperature control zones of the twin-screw extruder from the feeding section to the head are: the feeding section is 150 °C, the middle melting section is 160 °C, the homogenizing section and the head are 170 °C, the screw speed is 150 r / min. After cooling and pelletizing, rare earth modified polyvinyl chloride antibacterial composite material pellets are obtained.

[0037] Example 2

[0038] This example provides a preparation method of a rare earth modified polyvinyl chloride antibacterial composite material. 120 parts of polyvinyl chloride resin, 3 parts of cerium nitrate, 1.5 parts of γ-glycidyletheroxypropyltrimethoxysilane, 30 parts of epoxidized soybean oil, 5 parts of calcium-zinc stabilizer, and 3 parts of polyethylene wax are selected as the raw material formula.

[0039] The preparation specifically includes the following steps:

[0040] Step 1. Pretreatment of rare earth compound: Grind cerium nitrate to a particle size of 50 nm, mix it with γ-glycidyletheroxypropyltrimethoxysilane in xylene, and stir at a speed of 600 r / min and 100 °C for 4 h under nitrogen protection. After the reaction is completed, filter and wash, and vacuum dry at 100 °C for 24 h to obtain surface-modified cerium nitrate.

[0041] Step 2. Mixing: Add polyvinyl chloride resin, surface-modified cerium nitrate, epoxy soybean oil, calcium-zinc stabilizer, and polyethylene wax into a high-speed mixer, and mix at a speed of 1200 r / min and 120 °C for 15 minutes to obtain a uniform mixed material.

[0042] Step 3. Extrusion molding: Add the mixed material into a twin-screw extruder for melting and then extrusion. Among them, the temperature control zones of the twin-screw extruder are as follows: from the feeding section to the head, the temperatures are: 160 °C for the feeding section, 175 °C for the intermediate melting section, 180 °C for the homogenizing section and the head, the screw speed is 300 r / min. After cooling and pelletizing, rare earth-modified polyvinyl chloride antibacterial composite pellets are obtained.

[0043] Example 3

[0044] This example provides a preparation method of a rare earth-modified polyvinyl chloride antibacterial composite material, and 100 parts of polyvinyl chloride resin, 2 parts of cerium oxide, 1.2 parts of β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 20 parts of plasticizer (a 1:1 mixture of dioctyl phthalate and epoxy soybean oil), 3 parts of calcium-zinc stabilizer, and 2 parts of lubricant (a 1:1 mixture of stearic acid and polyethylene wax) are selected.

[0045] The preparation specifically includes the following steps:

[0046] Step 1. Pretreatment of rare earth compounds: Grind cerium oxide to a particle size of 30 nm, mix it with β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane in toluene, and stir at a speed of 450 r / min and 90 °C for 3 h under nitrogen protection. After the reaction is completed, filter and wash, and vacuum dry at 90 °C for 18 h to obtain surface-modified cerium oxide.

[0047] Step 2. Mixing: Add polyvinyl chloride resin, surface-modified cerium oxide, plasticizer, calcium-zinc stabilizer, and lubricant into a high-speed mixer, and mix at a speed of 1000 r / min and 110 °C for 12 minutes to obtain a uniform mixed material.

[0048] Step 3. Extrusion molding: Add the mixed material into a twin-screw extruder for melting and then extrusion. Among them, the temperature control zones of the twin-screw extruder are as follows: from the feeding section to the head, the temperatures are: 155 °C for the feeding section, 165 °C for the intermediate melting section, 175 °C for the homogenizing section and the head, the screw speed is 225 r / min. After cooling and pelletizing, rare earth-modified polyvinyl chloride antibacterial composite pellets are obtained.

[0049] Example 4

[0050] This example provides a preparation method of a rare earth-modified polyvinyl chloride antibacterial composite material, and the raw material formula is the same as that in Example 1, which will not be repeated here.

[0051] The preparation specifically includes the following steps:

[0052] Step 1. Pretreatment of rare earth compound: Grind lanthanum oxide to a particle size of 30 nm, mix it with N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane in xylene, and under nitrogen protection, stir at a speed of 500 r / min at 90 °C for 3 h. After the reaction is completed, filter and wash, and dry in vacuum at 90 °C for 18 h to obtain surface-modified lanthanum oxide.

[0053] Step 2. Mixing: Add polyvinyl chloride resin, surface-modified lanthanum oxide, dioctyl phthalate, calcium-zinc stabilizer, and stearic acid to a high-speed mixer, and mix at a speed of 1000 r / min at 110 °C for 12 minutes to obtain a uniform mixed material.

[0054] Step 3. Extrusion molding: Add the mixed material to a twin-screw extruder for melting and then extrusion. Among them, the temperature control zones of the twin-screw extruder are from the feeding section to the head: the feeding section is 155 °C, the intermediate melting section is 165 °C, the homogenizing section and the head are 175 °C, the screw speed is 225 r / min. After cooling and pelletizing, rare earth-modified polyvinyl chloride antibacterial composite pellets are obtained.

[0055] Example 5

[0056] This example provides a preparation method of a rare earth-modified polyvinyl chloride antibacterial composite material. The raw material formula is the same as that in Example 2, and will not be repeated here.

[0057] The preparation specifically includes the following steps:

[0058] Step 1. Pretreatment of rare earth compound: The same as the steps in Example 2.

[0059] Step 2. Mixing: The same as the steps in Example 2.

[0060] Step 3. Extrusion molding: The feeding section is 158 °C, the intermediate melting section is 172 °C, the homogenizing section and the head are 178 °C, the screw speed is 280 r / min, and the rest are the same as the steps in Example 2 to obtain rare earth-modified polyvinyl chloride antibacterial composite pellets.

[0061] Example 6

[0062] This example provides a preparation method of a rare earth-modified polyvinyl chloride antibacterial composite material. The raw material formula is the same as that in Example 3, and will not be repeated here.

[0063] The preparation specifically includes the following steps:

[0064] Step 1. Pretreatment of rare earth compound: The same as the steps in Example 2.

[0065] Step 2. Mixing: The same as in Example 2.

[0066] Step 3. Extrusion molding: The feeding section is at 140°C, the intermediate melting section is at 150°C, the homogenizing section and the die head are at 160°C, and the screw speed is 225 r / min. The rest is the same as in Example 2, obtaining the rare earth modified polyvinyl chloride antibacterial composite pellets.

[0067] Comparative Example 1: Without rare earth compounds

[0068] In this comparative example, 80 parts of polyvinyl chloride resin, 0.8 part of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, 10 parts of dioctyl phthalate, 2 parts of calcium-zinc stabilizer, and 1 part of stearic acid are selected as the raw material formulation.

[0069] The preparation specifically includes the following steps:

[0070] Step 1. Mixing: Add the raw materials to a high-speed mixer and mix at a speed of 800 r / min at 100°C for 10 minutes to obtain a uniform mixed material.

[0071] Step 2. Extrusion molding: Add the mixed material to a twin-screw extruder for melting and then extrusion. Among them, the temperature control zones of the twin-screw extruder from the feeding section to the die head are: the feeding section is at 150°C, the intermediate melting section is at 160°C, the homogenizing section and the die head are at 170°C, and the screw speed is 150 r / min. After cooling and pelletizing, polyvinyl chloride antibacterial composite pellets are obtained.

[0072] Comparative Example 2: Without surface modification

[0073] In this comparative example, 100 parts of polyvinyl chloride resin, 2 parts of cerium oxide, 20 parts of plasticizer (a 1:1 mixture of dioctyl phthalate and epoxidized soybean oil), 3 parts of calcium-zinc stabilizer, and 2 parts of lubricant (a 1:1 mixture of stearic acid and polyethylene wax) are selected as the raw material formulation.

[0074] The preparation specifically includes the following steps:

[0075] Step 1. Mixing: Add all the raw materials to a high-speed mixer and mix at a speed of 1000 r / min at 110°C for 12 minutes to obtain a uniform mixed material.

[0076] Step 2. Extrusion molding: Add the mixed material to a twin-screw extruder for melting and then extrusion. Among them, the temperature control zones of the twin-screw extruder from the feeding section to the die head are: the feeding section is at 155°C, the intermediate melting section is at 165°C, the homogenizing section and the die head are at 175°C, and the screw speed is 225 r / min. After cooling and pelletizing, rare earth modified polyvinyl chloride antibacterial composite pellets are obtained.

[0077] Comparative Example 3: Using different stabilizers

[0078] In this comparative example, 120 parts of polyvinyl chloride resin, 3 parts of lanthanum oxide, 1.5 parts of γ-glycidoxypropyltrimethoxysilane, 30 parts of epoxidized soybean oil, 5 parts of lead salt stabilizer, and 3 parts of polyethylene wax were selected as the raw material formula.

[0079] The preparation specifically includes the following steps:

[0080] Step 1: Pretreatment of rare earth compound: Grind lanthanum oxide to a particle size of 50 nm, mix it with γ-glycidoxypropyltrimethoxysilane in xylene, and under nitrogen protection, stir at a speed of 600 r / min and 100 °C for 4 h. After the reaction is completed, filter and wash, and vacuum dry at 100 °C for 24 h to obtain surface-modified lanthanum oxide.

[0081] Step 2: Mixing: Add polyvinyl chloride resin, surface-modified lanthanum oxide, epoxidized soybean oil, lead salt stabilizer, and polyethylene wax to a high-speed mixer, and mix at a speed of 1200 r / min and 120 °C for 15 minutes to obtain a uniform mixed material.

[0082] Step 3: Extrusion molding: Add the mixed material to a twin-screw extruder for melting and extrusion. Among them, the temperature control zones of the twin-screw extruder from the feeding section to the head are: the feeding section is 160 °C, the intermediate melting section is 175 °C, the homogenization section and the head are 180 °C, the screw speed is 300 r / min, and after cooling and pelletizing, rare earth-modified polyvinyl chloride antibacterial composite pellets are obtained.

[0083] Performance test

[0084] Escherichia coli, Staphylococcus aureus, and Candida albicans were selected as experimental strains to test the antibacterial and antifungal properties of the antibacterial and antifungal materials in Examples 1-6 and Comparative Examples 1-3 of the present invention. The specific steps are as follows:

[0085] (1) Obtain standard strains of Escherichia coli, Staphylococcus aureus, and Candida albicans from a professional strain preservation institution. Inoculate them into the corresponding liquid medium, and incubate in a constant temperature shaker at 37 °C at a rotation speed of 150 - 200 r / min for 18 - 24 hours to make the strains reach the logarithmic growth phase. Use a spectrophotometer to adjust the concentration of the bacterial suspension to 1×10 6 -1×10 7 CFU / mL.

[0086] (2) Prepare experimental instruments such as sterile petri dishes, sterile pipettes and tips, sterile normal saline, nutrient agar medium, test tubes, etc., and perform high-pressure steam sterilization treatment. The sterilization conditions are 121 °C for 20 - 30 minutes.

[0087] (3) Take the material samples of Examples 1-6 and Comparative Examples 1-3 and put them into sterile test tubes. Immerse them in 75% ethanol for 15-30 minutes for surface disinfection, then rinse them 3-5 times with sterile normal saline to remove the residual ethanol, and place them in a sterile environment to dry.

[0088] (4) Inoculate the bacterial solution: Pour about 15-20 mL of nutrient agar medium that has been cooled to 45-50 °C into a sterile petri dish and wait for it to solidify. Use a sterile pipette to aspirate 0.1 mL of the bacterial suspension with the adjusted concentration, evenly drop it on the surface of the agar medium, and spread the bacterial solution evenly with a sterile spreading rod.

[0089] (5) Gently place the dried material samples on the surface of the agar medium inoculated with the bacterial solution. Repeat 3-5 parallel samples for each material, and at the same time set up a blank control group without placing the material samples.

[0090] (6) Invert the petri dish and place it in an incubator at 37 °C for 24-48 hours. After the incubation is completed, observe and record the size of the antibacterial zone around the material samples. Use a vernier caliper to measure the diameter of the antibacterial zone, accurate to 0.1 mm. For materials that are difficult to form an obvious antibacterial zone, use the plate counting method to calculate the number of colonies on the petri dish, compare the number of colonies in the experimental group and the control group, and calculate the antibacterial rate. The results are shown in Table 1 below.

[0091] The formula for calculating the antibacterial rate is: Antibacterial rate (%) = (Number of colonies in the control group - Number of colonies in the experimental group) / Number of colonies in the control group × 100%.

[0092] Table 1 Antibacterial results

[0093]

[0094]

[0095] As can be seen from the data in Table 1, rare earth compounds play an indispensable core role in improving the antibacterial performance of polyvinyl chloride composites. In Comparative Example 1, rare earth compounds were not added, and its antibacterial rates against Escherichia coli, Staphylococcus aureus, and Candida albicans were much lower than those of each example, only 30.1%, 25.4%, and 20.8% respectively, indicating that rare earth compounds are the key components to endow the material with antibacterial properties.

[0096] Although Comparative Example 2 contains rare earth compounds, no surface modification was carried out, and its antibacterial rate was significantly lower than that of the examples. For example, for the antibacterial rate against Escherichia coli, Comparative Example 2 was 60.9%, while Example 3 was 96.5%. This shows that without surface modification of rare earth compounds, their dispersibility in the material is poor, and the antibacterial activity cannot be fully exerted. By surface-modifying rare earth compounds, not only is their dispersibility in the material enhanced, but also the synergistic effect between rare earth compounds and surface modifiers is promoted, thereby significantly improving the inhibitory ability of the material against various bacteria and fungi.

[0097] In Comparative Example 3, a lead salt stabilizer was used to replace the calcium-zinc stabilizer, and the antibacterial rate decreased compared to the examples. For example, for the antibacterial rate against Staphylococcus aureus, Comparative Example 3 was 80.4%, and Example 2 was 96.6%. This shows that an inappropriate stabilizer will change the chemical environment of the material system, interfere with the antibacterial effect of components such as rare earth compounds, and thus reduce the overall antibacterial performance of the material. The calcium-zinc stabilizer can provide a stable chemical environment for components such as rare earth compounds, ensuring the effective exertion of the antibacterial performance of the material.

[0098] Examples 1-6 used different raw material ratios and process parameters, and there were differences in the antibacterial rate. For example, the antibacterial rate of Example 5 against three types of bacteria was higher than that of other examples. It may be that by adjusting process parameters such as the extrusion temperature, the internal structure of the material became denser and more uniform, resulting in a higher antibacterial rate than other examples. On the contrary, after reducing the extrusion temperature in Example 6, the structure and performance of the material were affected to a certain extent, and the antibacterial rate against the three types of bacteria decreased to varying degrees. This shows that reasonably adjusting the raw material ratio and process parameters can significantly optimize the antibacterial performance of the material.

[0099] In summary, the preparation method of the rare earth-modified polyvinyl chloride antibacterial composite material provided by the present invention can effectively improve the antibacterial performance of the material against Escherichia coli, Staphylococcus aureus, and Candida albicans by reasonably using rare earth compounds, surface modification technology, stabilizers, and optimizing the raw material ratio and process parameters. Applying it to the preparation of medical devices can significantly improve the antibacterial and antifungal performance of medical devices.

[0100] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to preferred examples, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A rare earth modified polyvinyl chloride antibacterial composite material, characterized in that By weight parts, it comprises the following components: 80 - 120 parts of polyvinyl chloride resin, 1.5 - 3 parts of rare earth compound, 0.8 - 1.5 parts of surface modifier, 10 - 30 parts of plasticizer, 2 - 5 parts of stabilizer, 1 - 3 parts of lubricant.

2. The rare earth modified polyvinyl chloride antibacterial composite material according to claim 1, characterized in that: The rare earth compound is one or more of salts and oxides of lanthanum and salts and oxides of cerium.

3. The rare earth modified polyvinyl chloride antibacterial composite material according to claim 1, wherein, The surface modifier is one or more of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidyletheroxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

4. The rare earth modified polyvinyl chloride antibacterial composite material according to claim 1, wherein: The plasticizer is dioctyl phthalate or epoxidized soybean oil; the stabilizer is calcium-zinc stabilizer; the lubricant is stearic acid or polyethylene wax.

5. The preparation method of a rare earth modified polyvinyl chloride antibacterial composite material according to any one of claims 1-4, characterized in that, It includes the following steps: Step 1, pretreatment of rare earth compound: Grind the rare earth compound into nano-scale powder, then mix it with the surface modifier in an organic solvent, carry out stirring reaction under nitrogen protection. After the stirring reaction is completed, filter and wash, and vacuum dry at 80 - 100 °C for 12 - 24 h to obtain the surface-modified rare earth compound; Step 2, mixing: Add the polyvinyl chloride resin, pretreated rare earth compound, plasticizer, stabilizer and lubricant into a high-speed mixer to obtain a uniform mixed material; Step 3, extrusion molding: Add the mixed material into a twin-screw extruder, carry out melt extrusion in the temperature range of 160 - 180 °C, and obtain rare earth-modified polyvinyl chloride antibacterial composite pellets after cooling and pelletizing.

6. The preparation method of a rare earth modified polyvinyl chloride antibacterial composite material according to claim 5, wherein: In the said Step 1, the particle size of the ground rare earth compound is 20 - 50 nm; the organic solvent is toluene or xylene.

7. The preparation method of a rare earth modified polyvinyl chloride antibacterial composite material according to claim 5, characterized in that: In the said Step 1, the stirring speed is 300 - 600 r / min, the stirring temperature is 80 - 100 °C, and the stirring time is 2 - 4 h.

8. The preparation method of a rare earth modified polyvinyl chloride antibacterial composite material according to claim 5, characterized in that: In the said Step 2, the rotation speed of the high-speed mixer is 800 - 1200 r / min, the mixing temperature is 100 - 120 °C, and the mixing time is 10 - 15 minutes.

9. The preparation method of a rare earth modified polyvinyl chloride antibacterial composite material according to claim 5, characterized in that: In the said Step 3, in the temperature control zone of the twin-screw extruder, the temperature increases sequentially from the feeding section to the head. The temperature of the feeding section is 150 - 160 °C, the temperature of the intermediate melting section is 160 - 175 °C, the temperature of the homogenizing section and the head is 170 - 180 °C, and the rotation speed of the twin-screw is 150 - 300 r / min.

10. Use of a rare earth modified polyvinyl chloride antibacterial composite material according to any one of claims 1-4, characterized in that: The rare earth-modified polyvinyl chloride antibacterial composite is applied to the preparation of medical devices.

Images