Polymer material containing composite antibacterial agent and preparation method and application thereof

Abstract

This invention belongs to the field of polymer material preparation technology, and provides a polymer material containing a composite antibacterial agent, its preparation method, and its application. This invention uses 4A type molecular sieve zeolite as an inorganic carrier, and sequentially performs zinc salt ion exchange and silver salt ion exchange in an aqueous phase to obtain inorganic core powder loaded with metal ions. Subsequently, dopamine is introduced into a buffer system to form a surface transition layer, and orthosilicate, quaternary ammonium silane, and zwitterionic silane jointly construct an organosilicon surface coating layer. After the reaction, the mixture is redispersed and spray-dried to obtain composite antibacterial particles. Finally, the composite antibacterial particles are mixed with polybutylene terephthalate, pyromellitic dianhydride, hindered phenolic antioxidant, and phosphite antioxidant, and then melt-extruded, cooled, and pelletized to obtain a PBT-based polymer material containing a composite antibacterial agent. The obtained material has a uniform distribution of the composite antibacterial components and exhibits both long-lasting antibacterial properties and low migration characteristics.

Description

Technical Field

[0001] This invention belongs to the field of polymer material preparation technology, and relates to a polymer material containing a composite antibacterial agent, its preparation method and application. Background Technology

[0002] Polybutylene terephthalate (PBT), as an important class of polyester engineering plastics, is widely used in daily necessities, public facility components, and various products that come into contact with the human body due to its advantages such as light weight, corrosion resistance, ease of molding, and controllable cost. However, PBT and other polyester polymer materials typically have a certain degree of hydrophobicity and electrostatic adsorption effect on their surface, and are prone to micro-scratches and contaminant accumulation during use, thus providing conditions for the adhesion and reproduction of bacteria, fungi, and other microorganisms. After microorganisms form biofilms on the material surface, they can not only cause problems such as odor, discoloration, and mechanical property degradation, but also potentially lead to cross-contamination and hygiene risks. Therefore, long-lasting, broad-spectrum, and stable antibacterial PBT-based polymer materials have long been a focus of attention.

[0003] Existing antibacterial modification pathways mainly include adding inorganic antibacterial agents such as metal ions or metal oxides, introducing organic antibacterial agents such as quaternary ammonium salts, and surface coating or grafting modification. While inorganic antibacterial agents exhibit good heat resistance, they are prone to agglomeration in polyester matrices such as PBT, affecting appearance and processing stability. Furthermore, uncontrolled ion release may lead to insufficient antibacterial durability or migration risks. Organic antibacterial agents typically possess some compatibility, but they may become inactive, volatilize, or migrate under PBT melt processing temperatures and humid environments, resulting in a shortened effective lifespan. On the other hand, a single antibacterial mechanism often struggles to achieve both rapid antibacterial action and long-term stability. Increasing the addition amount to obtain sufficient effect can negatively impact the material's toughness, strength, color stability, and molding window. For engineering plastic systems such as polyester, the effects of processing shear and thermal history on the structure and dispersion of the antibacterial agent, as well as the precipitation and reduced durability caused by insufficient interfacial bonding between the antibacterial component and the matrix, must also be considered. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a polymeric material containing a composite antibacterial agent, its preparation method, and its application. The method involves constructing an inorganic metal ion core using molecular sieve zeolite as a carrier, and introducing a dopamine transition layer and an organosilicon surface coating layer onto its surface. This allows quaternary ammonium salts and zwitterionic functional groups to be synergistically fixed within the particle surface coating structure. After the reaction, the composite antibacterial particles are obtained through redispersing and spray drying. These particles are then melt-extruded with a polyester matrix and additives, and side-fed to obtain a uniformly dispersed, processable, and low-migration-risk antibacterial polymeric material, thus meeting the needs of practical production.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing a polymeric material containing a composite antibacterial agent, the method comprising:

[0007] S1, deionized water and 4A zeolite powder are mixed to obtain a carrier slurry. Zinc nitrate aqueous solution is added dropwise to the carrier slurry, and the pH is adjusted to 5.0-6.5 with nitric acid and reacted to obtain an inorganic slurry. Under light-protected conditions, silver nitrate aqueous solution is added dropwise to the inorganic slurry to obtain inorganic core powder.

[0008] S2, Tris buffer is mixed with inorganic nuclear powder, dopamine hydrochloride is added and reacted, and the pH is maintained at 8.3-8.9 with NaOH solution during the reaction to obtain intermediate powder. The intermediate powder is mixed with ethanol aqueous solution, and the pH is adjusted to 9.6-10.2 with ammonia. Tetraethyl orthosilicate, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate are added in sequence and the reaction continues. During the reaction, the pH is maintained at 9.4-10.3 with ammonia. After the reaction is completed, the mixture is filtered and washed, and the filter cake is redispersed to obtain slurry. Spray drying is then used to obtain composite antibacterial particles.

[0009] S3, PBT (polybutylene terephthalate) resin, pyromellitic dianhydride, antioxidant 1010 and antioxidant 168 are fed into a mixer to obtain a premix. The premix is ​​fed into a twin-screw extruder. After extrusion and reaching a stable state, composite antibacterial particles are fed into the fourth or fifth temperature zone through side feeding. After extrusion, the material is cooled, stretched into strips and granulated to obtain a polymer material containing composite antibacterial agents.

[0010] Specifically, it includes:

[0011] S1, deionized water and 4A zeolite powder are mixed to obtain a carrier slurry. Zinc nitrate aqueous solution is added dropwise to the carrier slurry, and the pH is adjusted to 5.0-6.5 with nitric acid. The reaction is carried out at the first temperature. After the reaction is completed, the mixture is centrifuged, washed, and redispersed in deionized water to obtain an inorganic slurry. Under light-protected conditions, silver nitrate aqueous solution is added dropwise to the inorganic slurry. The mixture is stirred at room temperature, then filtered and washed in the dark. The mixture is then vacuum dried to obtain inorganic core powder.

[0012] S2, Tris buffer and inorganic nuclear powder are mixed evenly, dopamine hydrochloride is added, and the reaction is carried out at room temperature. During the reaction, the pH is maintained at 8.3-8.9 with NaOH solution. After the reaction, the mixture is filtered, washed with deionized water and anhydrous ethanol in sequence, and dried to obtain intermediate powder. The intermediate powder and ethanol aqueous solution are mixed, and the pH is adjusted to 9.6-10.2 with ammonia. Under stirring at a second temperature, tetraethyl orthosilicate, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate are added in sequence and the reaction is continued. During the reaction, the pH is maintained at 9.4-10.3 with ammonia. After the reaction, the mixture is filtered and washed, and the filter cake is redispersed to obtain slurry. The slurry is spray-dried to obtain composite antibacterial particles.

[0013] S3, PBT resin, pyromellitic dianhydride, antioxidant 1010 and antioxidant 168 are fed into a mixer to obtain a premix. The premix is ​​fed into a twin-screw extruder. After extrusion and reaching a stable state, composite antibacterial particles are fed into the fourth or fifth temperature zone through side feeding. After extrusion, the material is cooled, drawn into strips and granulated to obtain a polymer material containing composite antibacterial agents.

[0014] Molecular sieve zeolites are porous materials with a negatively charged aluminosilicate framework, whose framework charge is balanced by exchangeable cations within the pores. When a zinc salt solution comes into contact with the zeolite, zinc ions in the solution enter the pores and exchange sites under the influence of concentration gradient and charge, thus establishing an ion pool within the zeolite with zinc ions as the main exchange cation. Subsequently, a silver salt solution is introduced under light-protected conditions. Silver ions enter the pores and occupy some exchange sites under a similar exchange mechanism, forming an exchange system where zinc and silver ions coexist. Metal ions are fixed in an exchange state at the pore and surface exchange sites. Dopamine undergoes oxidation in a weakly alkaline buffer system to form an ortho-quinone structure, which further undergoes intermolecular addition, condensation, and rearrangement reactions to form a polydopamine deposition layer. Polydopamine contains functional groups such as catechols, quinones, and amines, and can form an organic transition layer on the inorganic core surface through hydrogen bonding, π–π interactions, metal ion coordination, and interactions with surface hydroxyl groups or oxygen bridges. This deposition layer provides reaction sites containing phenolic hydroxyl and amine groups on the one hand, and changes the interfacial energy and surface charge of the particle surface on the other hand, thereby providing anchoring and nucleation conditions for the subsequent silane hydrolysis and condensation reaction.

[0015] Orthosilicates undergo hydrolysis under alkaline conditions to generate silanols. These silanols then condense to form siloxane bonds, gradually building a silica network. Simultaneously, quaternary ammonium silanes with alkoxysilane end groups and zwitterionic silanes also undergo hydrolysis to generate silanols, which then co-condense with the silanols obtained from the hydrolysis of orthosilicates. Due to the presence of phenolic hydroxyl and amino functional groups on the surface of polydopamine, silanols and their condensation intermediates preferentially nucleate and condense on the particle surface, allowing the silica network to preferentially deposit on the particle surface to form a surface coating layer. Quaternary ammonium groups are fixed to the silica network as co-condensed organic side chains, serving as positively charged contact antibacterial sites. Zwitterionic groups are also introduced into the coating layer surface as co-condensed side chains, forming an interface with an electrically neutral apparent charge and strong hydration capability. The covalent fixation of these two types of organic side chains in the silica network helps reduce their migration tendency in aqueous phases and under processing conditions. The surface coating layer is a cross-linked organosilicon network formed by the condensation of silanols.

[0016] The composite antibacterial particles and polyester matrix form a melt blend system under melt extrusion conditions. In the polyester melt, pyromellitic dianhydride can undergo a ring-opening reaction with terminal hydroxyl or carboxyl groups to generate ester bonds or carboxylic acid structures after anhydride ring-opening. This further condenses with other chain ends, thereby altering the end-group state of the polyester molecular chain and introducing chain growth or branching points. This reaction belongs to the nucleophilic ring-opening and subsequent condensation process between anhydrides and alcohols / carboxylic acids, increasing the participation of chemically linked end groups in the system and reducing end-group migration. The shell of the composite antibacterial particles contains a silicon-oxygen network and organic side chains. Esterification, hydrogen bonding, and dipole interactions may exist between silanol residues or surface polar groups and the polyester chain ends, as well as the carboxyl groups generated from the ring-opening of pyromellitic dianhydride, thus forming a more stable interfacial bonding state at the particle interface. The side-feeding method allows the composite antibacterial particles to enter the mixing section after the polyester melt is formed, reducing the probability of powder agglomeration under pressure in the solid phase section and retention under heat in the feeding section.

[0017] As a preferred embodiment of the present invention, in S1, the mass ratio of deionized water, 4A zeolite powder, zinc nitrate aqueous solution, and silver nitrate aqueous solution is (1800-2200):(180-220):(800-1200):(400-700), for example, it can be (1800, 1840, 1880, 1920, 1960, 2000, 2040, 2080, 2120, 2160, or 2200):(180, 184 ... 88, 192, 196, 200, 204, 208, 212, 216 or 220: (800, 840, 880, 920, 960, 1000, 1040, 1080, 1120, 1160 or 1200): (400, 430, 460, 490, 520, 550, 580, 610, 640, 670 or 700), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0018] In some optional embodiments, the D50 of the 4A zeolite powder is 2-6 μm, for example, it can be 2.0 μm, 2.4 μm, 2.8 μm, 3.2 μm, 3.6 μm, 4.0 μm, 4.4 μm, 4.8 μm, 5.2 μm, 5.6 μm or 6.0 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0019] In some alternative embodiments, the concentration of the zinc nitrate aqueous solution is 0.4-0.6M, for example, it can be 0.4M, 0.42M, 0.44M, 0.46M, 0.48M, 0.5M, 0.52M, 0.54M, 0.56M, 0.58M or 0.6M, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0020] In some alternative embodiments, the concentration of nitric acid is 1-2M, for example, it can be 1.0M, 1.1M, 1.2M, 1.3M, 1.4M, 1.5M, 1.6M, 1.7M, 1.8M, 1.9M or 2.0M, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0021] In some alternative embodiments, the first temperature is 55-65°C, for example, it can be 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C or 65°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0022] In some alternative embodiments, the reaction time at the first temperature is 1.5-2.5 h, for example, it can be 1.5 h, 1.6 h, 1.7 h, 1.8 h, 1.9 h, 2.0 h, 2.1 h, 2.2 h, 2.3 h, 2.4 h or 2.5 h, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0023] In some optional embodiments, the concentration of the silver nitrate aqueous solution is 0.008-0.015M, for example, it can be 0.008M, 0.0087M, 0.0094M, 0.0101M, 0.0108M, 0.0115M, 0.0122M, 0.0129M, 0.0136M, 0.0143M or 0.015M, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0024] In some optional embodiments, the stirring time at room temperature is 0.8-1.5 h, for example, it can be 0.8 h, 0.87 h, 0.94 h, 1.01 h, 1.08 h, 1.15 h, 1.22 h, 1.29 h, 1.36 h, 1.43 h or 1.5 h, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0025] As a preferred embodiment of the present invention, in S2, the mass ratio of the Tris buffer, inorganic nuclear powder, and dopamine hydrochloride is (1800-2200):(90-110):(1.6-3), for example, it can be (1800, 1840, 1880, 1920, 1960, 2000, 2040, 2080, 2120, 2160 or 2200):(90, 92, 94, 96, 98, 100, 102, 104, 106, 108 or 110):(1.6, 1.74, 1.88, 2.02, 2.16, 2.3, 2.44, 2.58, 2.72, 2.86 or 3.0), but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0026] In some alternative embodiments, the Tris buffer solution has a concentration of 8-12 mM and a pH of 8.4-8.7, for example, a concentration of (8, 8.4, 8.8, 9.2, 9.6, 10.0, 10.4, 10.8, 11.2, 11.6 or 12) mM and a pH of (8.4, 8.43, 8.46, 8.49, 8.52, 8.55, 8.58, 8.61, 8.64, 8.67 or 8.7), but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0027] In some alternative embodiments, the room temperature reaction time is 4-6 hours, for example, 4.0 hours, 4.2 hours, 4.4 hours, 4.6 hours, 4.8 hours, 5.0 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours, or 6.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0028] In some optional embodiments, the concentration of the NaOH solution is 0.1-0.2M, for example, it can be 0.1M, 0.11M, 0.12M, 0.13M, 0.14M, 0.15M, 0.16M, 0.17M, 0.18M, ​​0.19M or 0.2M, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0029] In some optional embodiments, the mass ratio of the intermediate powder, aqueous ethanol solution, tetraethyl orthosilicate, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate is (70-90):(1450-1750):(18-28):(6-14):(6-14), for example, it can be (70, 72, 74, 76, 78, 80, 82, 84, 86, 88 or 90):(1450, 1480, 1510, 1540, ... 1570, 1600, 1630, 1660, 1690, 1720 or 1750: (18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28): (6, 6.8, 7.6, 8.4, 9.2, 10, 10.8, 11.6, 12.4, 13.2 or 14): (6, 6.8, 7.6, 8.4, 9.2, 10, 10.8, 11.6, 12.4, 13.2 or 14), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0030] In some optional embodiments, the volume ratio of anhydrous ethanol to deionized water in the aqueous ethanol solution is 8:2.

[0031] In some alternative embodiments, the second temperature is 28-35°C, for example, it can be 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C or 35°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0032] In some optional embodiments, the continued reaction time is 5-8 hours, for example, 5.0 hours, 5.3 hours, 5.6 hours, 5.9 hours, 6.2 hours, 6.5 hours, 6.8 hours, 7.1 hours, 7.4 hours, 7.7 hours, or 8.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0033] In some optional embodiments, the mass fraction of the ammonia solution is 25-28 wt.%, for example, it can be 25.0 wt.%, 25.3 wt.%, 25.6 wt.%, 25.9 wt.%, 26.2 wt.%, 26.5 wt.%, 26.8 wt.%, 27.1 wt.%, 27.4 wt.%, 27.7 wt.%, or 28.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0034] In some optional embodiments, the slurry solid content is 6-10 wt.%; for example, it can be 6 wt.%, 6.4 wt.%, 6.8 wt.%, 7.2 wt.%, 7.6 wt.%, 8.0 wt.%, 8.4 wt.%, 8.8 wt.%, 9.2 wt.%, 9.6 wt.%, or 10 wt.%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0035] As a preferred embodiment of the present invention, in S3, the mass ratio of PBT resin, pyromellitic dianhydride, antioxidant 1010, antioxidant 168, and composite antibacterial particles is (9200-9750):(5-20):(5-15):(5-15):(200-280), for example, it can be (9200, 9255, 9310, 9365, 9420, 9475, 9530, 9585, 9640, 9695, or 9750):(5, 6). 5, 8, 9.5, 11, 12.5, 14, 15.5, 17, 18.5 or 20: (5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15): (5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15): (200, 208, 216, 224, 232, 240, 248, 256, 264, 272 or 280), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0036] In some optional embodiments, the twin-screw extruder has the following temperature zones set sequentially from the feeding section to the die head: 235 / 245 / 250 / 250 / 250 / 245 / 240 / 235°C, a screw speed of 240-360 rpm, and an 80-120 mesh filter screen at the die head. For example, the temperature zone from the feeding section to the die head could be set sequentially to 235 / 245 / 250 / 250 / 250 / 245 / 240 / 235℃, the screw speed to be (240, 252, 264, 276, 288, 300, 312, 324, 336, 348 or 360) rpm, and the die head to be equipped with a (80, 84, 88, 92, 96, 100, 104, 108, 112, 116 or 120) mesh filter. However, this is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0037] Secondly, the present invention provides a polymeric material containing a composite antibacterial agent prepared by the preparation method described in the first aspect.

[0038] Thirdly, the present invention provides an application of a polymer material containing a composite antibacterial agent in oral care.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention constructs an ion-exchangeable inorganic core using molecular sieve zeolite, fixing metal ions in an exchangeable state within the channels and exchange sites, thereby reducing their tendency to ionize and migrate in the PBT-based polymer system; a polydopamine transition layer is introduced on the surface of the inorganic core and further forms an organosilicon surface coating layer, allowing quaternary ammonium salt groups and zwitterionic groups to be covalently embedded in the silicon-oxygen network, which helps to improve the structural stability and interfacial compatibility of the composite antibacterial particles; the composite antibacterial particles are added through side feeding during the melt extrusion process of the PBT polyester matrix, which helps to suppress powder agglomeration and achieve uniform dispersion, reducing the thermal impact during processing. The PBT-based antibacterial material obtained thereby has both long-lasting antibacterial and low migration characteristics, good molding adaptability, and is suitable for common processing methods such as injection molding and extrusion. Attached Figure Description

[0040] Figure 1 This is a SEM image of the inorganic core powder provided in Embodiment 1 of the present invention. Detailed Implementation

[0041] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0042] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone any further purification treatment.

[0043] Example 1

[0044] This embodiment provides a polymeric material containing a composite antibacterial agent and its preparation method. The preparation method specifically includes the following steps:

[0045] S1, 1800g of deionized water and 220g of 4A zeolite powder were mixed to obtain a carrier slurry. The 4A zeolite powder had a D50 of 2μm. 800g of 0.6M zinc nitrate aqueous solution was added dropwise to the carrier slurry, and the pH was adjusted to 5.0 with 1M nitric acid. The mixture was reacted at 65℃ for 1.5h. After the reaction, the mixture was centrifuged, washed, and redispersed in deionized water to obtain an inorganic slurry. Under light-protected conditions, 700g of 0.008M silver nitrate aqueous solution was added dropwise to the inorganic slurry. The mixture was stirred at room temperature for 1.5h, then filtered, washed in the dark, and vacuum dried to obtain inorganic core powder. Figure 1 The SEM image of the inorganic core powder shows that the inorganic core powder particles have a regular block or cubic shape, and the particle boundaries are relatively clear.

[0046] S2, 1800g of 12mM Tris buffer solution (pH 8.4) was mixed with 110g of inorganic nuclear powder. 1.6g of dopamine hydrochloride was added, and the mixture was reacted at room temperature for 6 hours, maintaining the pH at 8.3 with 0.2M NaOH solution during the reaction. After the reaction, the mixture was filtered, washed successively with deionized water and anhydrous ethanol, and dried to obtain intermediate powder. 70g of the intermediate powder was mixed with 1750g of an ethanol-water solution (the volume ratio of anhydrous ethanol to deionized water was 8:2). The pH was adjusted to 9.6 using 28wt.% ammonia solution. Under stirring at 35°C, 18g of tetraethyl orthosilicate, 14g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and 6g of... 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate was reacted for 5 hours. During the reaction, ammonia was used to maintain the pH at 10.3. After the reaction, the mixture was filtered and washed. The filter cake was redispersed to obtain a slurry with a solid content of 6 wt.%. The slurry was then spray-dried to obtain composite antibacterial particles.

[0047] S3, 9750g of PBT resin, 5g of pyromellitic dianhydride, 15g of antioxidant 1010 and 5g of antioxidant 168 are added to a mixer to obtain a premix. The premix is ​​then fed into a twin-screw extruder. The twin-screw extruder has the following temperature zones set sequentially from the feeding section to the die head: 235 / 245 / 250 / 250 / 250 / 245 / 240 / 235℃, screw speed 240rpm, and a 120-mesh filter screen at the die head. After extrusion reaches a stable state, 280g of composite antibacterial particles are fed into the fourth temperature zone via side feeding. After extrusion, the material is cooled, stretched, and pelletized to obtain a polymer material containing composite antibacterial agents.

[0048] Example 2

[0049] This embodiment provides a polymeric material containing a composite antibacterial agent and its preparation method. The preparation method specifically includes the following steps:

[0050] S1, 2200g of deionized water and 180g of 4A zeolite powder were mixed to obtain a carrier slurry. The 4A zeolite powder had a D50 of 6μm. 1200g of 0.4M zinc nitrate aqueous solution was added dropwise to the carrier slurry, and the pH was adjusted to 6.5 with 2M nitric acid. The mixture was reacted at 55℃ for 2.5h. After the reaction, the mixture was centrifuged, washed, and redispersed in deionized water to obtain an inorganic slurry. Under light-protected conditions, 400g of 0.015M silver nitrate aqueous solution was added dropwise to the inorganic slurry. The mixture was stirred at room temperature for 0.8h, then filtered, washed in the dark, and vacuum dried to obtain inorganic core powder.

[0051] S2, 2200g of 8mM Tris buffer solution (pH 8.7) was mixed thoroughly with 90g of inorganic nuclear powder. 3.0g of dopamine hydrochloride was added, and the mixture was reacted at room temperature for 4 hours, maintaining the pH at 8.9 using 0.1M NaOH solution during the reaction. After the reaction, the mixture was filtered, washed successively with deionized water and anhydrous ethanol, and dried to obtain intermediate powder. 90g of the intermediate powder was mixed with 1450g of an ethanol-water solution (the volume ratio of anhydrous ethanol to deionized water was 8:2). The pH was adjusted to 10.2 using 25wt.% ammonia solution. Under stirring at 28℃, 28g of tetraethyl orthosilicate, 6g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and 14g of... 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate was reacted for 8 hours. During the reaction, ammonia was used to maintain the pH at 9.4. After the reaction, the mixture was filtered and washed. The filter cake was redispersed to obtain a slurry with a solid content of 10 wt.%. The slurry was then spray-dried to obtain composite antibacterial particles.

[0052] S3, 9200g of PBT resin, 20g of pyromellitic dianhydride, 5g of antioxidant 1010 and 15g of antioxidant 168 are added to a mixer to obtain a premix. The premix is ​​then fed into a twin-screw extruder. The twin-screw extruder has the following temperature zones set sequentially from the feeding section to the die head: 235 / 245 / 250 / 250 / 250 / 245 / 240 / 235℃, screw speed 360rpm, and an 80-mesh filter screen at the die head. After extrusion reaches a stable state, 200g of composite antibacterial particles are fed into the fifth temperature zone via side feeding. After extrusion, the material is cooled, stretched, and pelletized to obtain a polymer material containing composite antibacterial agents.

[0053] Example 3

[0054] This embodiment provides a polymeric material containing a composite antibacterial agent and its preparation method. The preparation method specifically includes the following steps:

[0055] S1, 2000g of deionized water and 200g of 4A zeolite powder were mixed to obtain a carrier slurry. The 4A zeolite powder had a D50 of 4μm. 1000g of 0.5M zinc nitrate aqueous solution was added dropwise to the carrier slurry, and the pH was adjusted to 5.8 with 1.5M nitric acid. The mixture was reacted at 60℃ for 2.0h. After the reaction, the mixture was centrifuged, washed, and redispersed in deionized water to obtain an inorganic slurry. Under light-protected conditions, 550g of 0.01M silver nitrate aqueous solution was added dropwise to the inorganic slurry. The mixture was stirred at room temperature for 1.0h, then filtered, washed in the dark, and vacuum dried to obtain inorganic core powder.

[0056] S2, 2000g of 10mM Tris buffer solution (pH 8.5) was mixed thoroughly with 100g of inorganic nuclear powder. 2.2g of dopamine hydrochloride was added, and the mixture was reacted at room temperature for 5 hours, maintaining the pH at 8.6 using 0.15M NaOH solution during the reaction. After the reaction, the mixture was filtered, washed successively with deionized water and anhydrous ethanol, and dried to obtain intermediate powder. 80g of the intermediate powder was mixed with 1600g of an ethanol-water solution (the volume ratio of anhydrous ethanol to deionized water was 8:2). The pH was adjusted to 9.8 using 26wt.% ammonia solution. Under stirring at 32℃, 22g of tetraethyl orthosilicate, 10g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and 10g of... 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate was reacted for 6.5 h. During the reaction, ammonia was used to maintain the pH at 9.8. After the reaction, the mixture was filtered and washed. The filter cake was redispersed to obtain a slurry with a solid content of 8 wt.%. The slurry was then spray-dried to obtain composite antibacterial particles.

[0057] S3, 9500g of PBT resin, 12g of pyromellitic dianhydride, 10g of antioxidant 1010 and 10g of antioxidant 168 are added to a mixer to obtain a premix. The premix is ​​then fed into a twin-screw extruder. The twin-screw extruder has the following temperature zones set sequentially from the feeding section to the die head: 235 / 245 / 250 / 250 / 250 / 245 / 240 / 235℃, screw speed 300rpm, and a 100-mesh filter screen at the die head. After extrusion reaches a stable state, 240g of composite antibacterial particles are fed into the fourth temperature zone via side feeding. After extrusion, the material is cooled, stretched, and pelletized to obtain a polymer material containing composite antibacterial agents.

[0058] Example 4

[0059] This embodiment provides a polymeric material containing a composite antibacterial agent and its preparation method. The preparation method specifically includes the following steps:

[0060] S1, 2100g of deionized water and 190g of 4A zeolite powder were mixed to obtain a carrier slurry. The 4A zeolite powder had a D50 of 5μm. 900g of 0.55M zinc nitrate aqueous solution was added dropwise to the carrier slurry, and the pH was adjusted to 6.0 with 1.8M nitric acid. The mixture was reacted at 62℃ for 2.2h. After the reaction, the mixture was centrifuged, washed, and redispersed in deionized water to obtain an inorganic slurry. Under light-protected conditions, 600g of 0.012M silver nitrate aqueous solution was added dropwise to the inorganic slurry. The mixture was stirred at room temperature for 1.2h, then filtered, washed in the dark, and vacuum dried to obtain inorganic core powder.

[0061] S2, 2100g of 9mM Tris buffer solution (pH 8.6) was mixed thoroughly with 95g of inorganic nuclear powder. 2.5g of dopamine hydrochloride was added, and the mixture was reacted at room temperature for 5.5h, maintaining the pH at 8.7 using 0.18M NaOH solution during the reaction. After the reaction, the mixture was filtered, washed successively with deionized water and anhydrous ethanol, and dried to obtain intermediate powder. 85g of the intermediate powder was mixed with 1500g of an ethanol-water solution (the volume ratio of anhydrous ethanol to deionized water was 8:2). The pH was adjusted to 10.0 using 27wt.% ammonia solution. Under stirring at 30℃, 25g of tetraethyl orthosilicate, 8g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and 12g of... 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate was reacted for 7 hours. During the reaction, ammonia was used to maintain the pH at 9.6. After the reaction, the mixture was filtered and washed. The filter cake was redispersed to obtain a slurry with a solid content of 9 wt.%. The slurry was then spray-dried to obtain composite antibacterial particles.

[0062] S3, 9400g of PBT resin, 18g of pyromellitic dianhydride, 8g of antioxidant 1010 and 12g of antioxidant 168 are fed into a mixer to obtain a premix. The premix is ​​then fed into a twin-screw extruder. The twin-screw extruder has the following temperature zones set sequentially from the feeding section to the die head: 235 / 245 / 250 / 250 / 250 / 245 / 240 / 235℃, screw speed 320rpm, and a 90-mesh filter screen at the die head. After extrusion reaches a stable state, 220g of composite antibacterial particles are fed into the fifth temperature zone via side feeding. After extrusion, the material is cooled, stretched, and pelletized to obtain a polymer material containing composite antibacterial agents.

[0063] Comparative Example 1

[0064] This comparative example provides a polymeric material containing a composite antibacterial agent and its preparation method. The difference between this example and Example 1 is that in S1, after completing the zinc nitrate ion exchange and obtaining the inorganic slurry, the silver nitrate solution ion exchange step is no longer performed. Instead, the inorganic slurry is directly post-treated to obtain inorganic core powder containing only zinc ion exchange state. Other process parameters and operating conditions are exactly the same as in Example 1.

[0065] Comparative Example 2

[0066] This comparative example provides a polymeric material containing a composite antibacterial agent and its preparation method. The difference between this example and Example 1 is that in S1, 4A zeolite powder is replaced with silica powder of similar particle size as a carrier. Other process parameters and operating conditions are exactly the same as in Example 1.

[0067] Comparative Example 3

[0068] This comparative example provides a polymeric material containing a composite antibacterial agent and its preparation method. The difference between this and Example 1 is that dopamine hydrochloride is not added in S2, nor is the corresponding room temperature reaction process carried out. Instead, the inorganic core powder obtained in S1 is directly dispersed in an ethanol aqueous solution and the pH is adjusted with ammonia. Then, tetraethyl orthosilicate, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate are added to react and obtain composite antibacterial particles. Other process parameters and operating conditions are exactly the same as in Example 1.

[0069] Comparative Example 4

[0070] This comparative example provides a polymeric material containing a composite antibacterial agent and its preparation method. The difference between this example and Example 1 is that only tetraethyl orthosilicate is added in S2 for the sol-gel reaction, and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonium}propane-1-sulfonate are not added. Other process parameters and operating conditions are exactly the same as in Example 1.

[0071] Performance testing:

[0072] The test method for surface antibacterial activity is ISO 22196;

[0073] The test method for dynamic contact antimicrobial activity is ASTM E2149;

[0074] The migration / precipitation test method is as follows: Take the material sample after injection molding or extrusion molding, rinse the surface thoroughly with deionized water and dry it. Under clean conditions, cut the sample into fragments with a side length of about 1 cm and mix them evenly. Weigh 2.0 g of the sample and place it in a polytetrafluoroethylene extraction bottle that has been pre-acid-washed and rinsed with deionized water. Add 50 mL of 0.9 wt.% sodium chloride aqueous solution as the extraction solution. Tighten the cap and place the bottle in a constant temperature shaker. Extract for 24 h at 40℃ and a shaking rate of 100 rpm. After extraction, take the sample... The clarified extract was obtained by filtration through a 0.22 μm filter membrane. Superior purity nitric acid was added to the extract to achieve a final nitric acid volume fraction of 1 wt.% for preservation and stabilization. A blank control containing only the extract and no sample was prepared and treated under the same conditions. The silver and zinc contents in the extract were determined using inductively coupled plasma atomic emission spectrometry (ICP-AES). The analytical procedures, including instrument ignition, wavelength selection, calibration curve establishment, matrix correction, and quality control, were performed in accordance with ISO 11885. The test results are expressed as the mass concentrations of silver and zinc in the extract.

[0075] The test results of the polymer materials containing composite antibacterial agents prepared in Examples 1-4 and Comparative Examples 1-4 are shown in Table 1.

[0076] Table 1. Test results of polymer materials containing composite antibacterial agents in Examples 1-4 and Comparative Examples 1-4

[0077]

[0078] As shown in Table 1, compared with Example 1, Comparative Example 1 showed decreased surface antibacterial activity, decreased dynamic contact antibacterial activity, and increased zinc content; Comparative Example 2 showed decreased surface antibacterial activity, decreased dynamic contact antibacterial activity, increased zinc content, and increased silver content; Comparative Example 3 showed decreased surface antibacterial activity, decreased dynamic contact antibacterial activity, increased zinc content, and increased silver content; and Comparative Example 4 showed decreased surface antibacterial activity, decreased dynamic contact antibacterial activity, decreased zinc content, and decreased silver content.

[0079] This is because, in Comparative Example 1, only Zn ion exchange was performed, and the absence of Ag weakened the rapid killing pathway for some bacteria. Although the silica shell and the covalent fixation of quaternary ammonium salt / zwitterionic groups were still retained, the synergy between the metal ion pool and the contact sites was insufficient, resulting in a decline in both surface antibacterial activity and dynamic contact antibacterial activity. In Comparative Example 2, after the carrier was changed from 4A zeolite to SiO2, stable ion exchange sites were lacking. Zn / Ag was more likely to exist in an adsorbed or deposited state, and was more easily displaced into the leaching solution during salt extraction. Therefore, the Zn and Ag extraction values ​​increased, and the metal components were in a highly mobile state in the system, resulting in a decrease in antibacterial effect. In Comparative Example 3, after omitting the dopamine transition layer, the nucleation and anchoring of the silica sol-gel coating was insufficient, the integrity of the coating layer decreased, and the opportunity for direct contact between the local inorganic core surface and the leaching solution increased. This made it easier for the Zn / Ag exchange state to be extracted by the salt solution. The uneven coating layer also caused discontinuous distribution of quaternary ammonium salt / zwitterionic groups on the surface, resulting in a decrease in both surface and dynamic contact antibacterial activity. In Comparative Example 4, when only TEOS was used to form a SiO2 coating layer without introducing quaternary ammonium silane and zwitterionic silane, the coating layer surface lacked immobilized charged contact sites and zwitterionic hydration interfaces, and the antibacterial mechanism mainly relied on the release of metal ions through exchange. At the same time, the inert SiO2 shell had a certain inhibitory effect on ion migration, resulting in a Zn / Ag extraction value lower than that of the example. Due to the lack of surface functional groups, even if migration was reduced, the surface and dynamic contact antibacterial properties still decreased.

[0080] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a polymeric material containing a composite antibacterial agent, characterized in that, The preparation method comprises: S1, mixing deionized water and 4A zeolite powder to obtain a carrier slurry, adding an aqueous zinc nitrate solution into the carrier slurry, adjusting pH with nitric acid and reacting to obtain an inorganic slurry, adding an aqueous silver nitrate solution into the inorganic slurry under light-proof conditions to obtain an inorganic core powder; S2, mixing Tris buffer and the inorganic core powder, adding dopamine hydrochloride to react and adjusting pH with NaOH solution during the reaction to obtain an intermediate powder, mixing the intermediate powder with an ethanol aqueous solution, adjusting pH with ammonia water, sequentially adding tetraethyl orthosilicate, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonio}propane-1-sulfonate and continuing to react, adjusting pH with ammonia water during the reaction, filtering and washing after the reaction, redispersing the filter cake to obtain a slurry, and spray drying to obtain composite antibacterial particles; S3, putting PBT resin, pyromellitic dianhydride, antioxidant 1010 and antioxidant 168 into a mixer to obtain a premix, putting the premix into a twin-screw extruder, feeding the composite antibacterial particles through the side feed in the fourth temperature zone or the fifth temperature zone after extrusion into a stable state, cooling and drawing the extruded material, and pelletizing to obtain a polymer material containing a composite antibacterial agent.

2. The method for preparing a polymer material containing a composite antibacterial agent according to claim 1, characterized in that, In S1: The mass ratio of the deionized water, 4A zeolite powder, aqueous zinc nitrate solution and aqueous silver nitrate solution is (1800-2200):(180-220):(800-1200):(400-700).

3. The method for preparing a polymer material containing a composite antibacterial agent according to claim 1, characterized in that, In S1: The concentration of the aqueous zinc nitrate solution is 0.4-0.6M; The concentration of the aqueous silver nitrate solution is 0.008-0.015M.

4. The method of claim 1, wherein the method is characterized by the steps of: In S2: The mass ratio of the Tris buffer, inorganic core powder and dopamine hydrochloride is (1800-2200):(90-110):(1.6-3); The concentration of the Tris buffer is 8-12mM, and the pH is 8.4-8.

7.

5. The method of claim 1, wherein the method is characterized by the steps of: In S2: The mass ratio of the intermediate powder, ethanol aqueous solution, tetraethyl orthosilicate, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 3-{(dimethyl(3-trimethoxysilyl)propyl)ammonio}propane-1-sulfonate is (70-90):(1450-1750):(18-28):(6-14):(6-14).

6. The method of claim 1, wherein the method is characterized by the steps of: In S2: The solid content of the slurry is 6-10wt.%.

7. The method of claim 1, wherein the method is characterized by the steps of: (a) dissolving the polymer in a solvent; (b) adding the complexing antibacterial agent to the solution; (c) removing the solvent; and (d) recovering the polymer material containing the complexing antibacterial agent. In S3: The mass ratio of the PBT resin, pyromellitic dianhydride, antioxidant 1010, antioxidant 168 and composite antibacterial particles is (9200-9750):(5-20):(5-15):(5-15):(200-280).

8. The method of claim 1, wherein the method is characterized by the steps of: In S3: The twin-screw extruder is set as follows from the feeding section to the die head: 235 / 245 / 250 / 250 / 250 / 245 / 240 / 235℃, the screw rotation speed is 240-360rpm, and the die head is configured with a 80-120 mesh filter screen.

9. A polymeric material containing a composite antibacterial agent obtained by the preparation method according to any one of claims 1-8.

10. The application of a polymeric material containing a composite antibacterial agent obtained by the preparation method according to any one of claims 1-8 in oral care.

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