Antibacterial modified PC / ABS composite material and preparation method thereof

Abstract

This invention relates to the field of polymer technology and discloses an antibacterial modified PC / ABS composite material and its preparation method. The antibacterial modified PC / ABS composite material of this invention comprises the following raw materials in parts by weight: 30-60 parts ABS resin, 10-50 parts PC resin, 1-3 parts modified antibacterial agent, 2-4 parts modified flame retardant, 3-6 parts toughening agent, 0.5-1 part antioxidant, 0.5-1 part polyethylene wax, and 0.5-1.5 parts maleic anhydride-grafted polyethylene. The modified antibacterial agent of this invention can effectively kill common pathogenic microorganisms such as Escherichia coli and Staphylococcus aureus, and its antibacterial performance is long-lasting and stable. The modified flame retardant can simultaneously exert a dual effect of gas-phase flame retardancy and condensed-phase charring during the material's heating and combustion processes, endowing the material with excellent flame-retardant properties.

Description

Technical Field

[0001] This invention relates to the field of polymer technology, specifically to an antibacterial modified PC / ABS composite material and its preparation method. Background Technology

[0002] PC / ABS composite material is a high-performance engineering plastic alloy prepared by blending and modifying polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS). After proper blending, the two materials can complement each other's properties, resulting in a composite material with high impact resistance, easy processing, dimensional stability, and strong design flexibility. Currently, downstream applications have clearly defined requirements for the antibacterial and bacteriostatic properties of PC / ABS materials. During use, products such as home appliances, medical devices, public contact facilities, and consumer electronics are prone to the growth of pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, and Candida albicans on their surfaces. This not only easily causes cross-contamination and threatens user health, but the microbial metabolites also accelerate the aging and degradation of the material matrix, shortening the product's lifespan. Currently, the most commonly used antibacterial raw materials are inorganic silver-based antibacterial agents, while zinc / copper-based inorganic antibacterial agents, quaternary ammonium salts, and guanidine organic antibacterial agents are also used. Although inorganic silver-based antibacterial agents have the advantages of broad-spectrum antibacterial activity and good heat resistance, during the high-temperature processing of PC / ABS, silver ions are easily reduced and discolored, severely affecting the appearance of light-colored and transparent products. Furthermore, halogen-free modification has become the core development direction for flame retardant modification of PC / ABS. Commonly used inorganic flame retardants require high addition amounts to meet the flame retardant grade requirements, which will seriously degrade the mechanical properties of PC / ABS composite materials and make it difficult to meet the production requirements of high-end products.

[0003] Patent application number 201310743437.X discloses a wear-resistant, flame-retardant, and antibacterial PC / ABS alloy material and its preparation method. It uses an inorganic carrier, silver-zinc nano-antibacterial agent, to improve the antibacterial properties of the alloy material. However, the nano-scale antibacterial powder is prone to agglomeration, making it difficult to achieve uniform nano-scale dispersion in the matrix. This not only leads to unstable antibacterial properties but also causes a decline in mechanical properties. Patent application number 201410439032.1 discloses an aging-resistant and antibacterial PC / ABS blend alloy and its preparation method. It uses nano-titanium dioxide as a light-stabilized antibacterial agent to improve the material's antibacterial durability. However, its antibacterial properties are only activated under ultraviolet light irradiation, limiting the actual antibacterial effect. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an antibacterial modified PC / ABS composite material and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An antibacterial modified PC / ABS composite material comprises the following raw materials in parts by weight: 30-60 parts ABS resin, 10-50 parts PC resin, 1-3 parts modified antibacterial agent, 2-4 parts modified flame retardant, 3-6 parts toughening agent, 0.5-1 part antioxidant, 0.5-1 part polyethylene wax, and 0.5-1.5 parts maleic anhydride grafted polyethylene.

[0007] The toughening agent is a methyl methacrylate-butadiene-styrene copolymer;

[0008] The antioxidant is at least one of antioxidant 1076 and antioxidant 168;

[0009] The modified antibacterial agent is prepared by the following steps:

[0010] Step A1: Mix 1,2-benzisothiazol-3-one, 8wt% sodium hydroxide aqueous solution and chloroethanol, place in a microwave reactor, stir and react at 75℃ for 1h. After the reaction is completed, distill under reduced pressure, add dichloromethane and stir, dry, filter, distill under reduced pressure and recrystallize to obtain intermediate product 1.

[0011] Furthermore, the ratio of 1,2-benzisothiazol-3-one, sodium hydroxide aqueous solution, chloroethanol, and dichloromethane is 0.4-0.6 mol: 100-150 mL: 0.1-0.15 mol: 300-400 mL;

[0012] In step A1, 1,2-benzisothiazolinone and chloroethanol undergo a nucleophilic substitution reaction, introducing a hydroxyl group into the system and providing reaction conditions for the subsequent ring-opening reaction. The introduced benzisothiazolinone has high antibacterial activity. Intracellular target proteins or glutathione readily react with the nitrogen-sulfur bonds in the molecular structure, leading to the breaking of nitrogen-sulfur bonds, opening of heterocycles, and formation of disulfides. These disulfides interfere with the enzymatic process, causing cell dysfunction and ultimately leading to bacterial death.

[0013] Step A2: Mix intermediate product 1 with toluene, stir and heat to 80°C, add boron trifluoride-diethyl ether complex, add 2,3-epoxypropyltrimethylammonium chloride solution dropwise, after the addition is complete, reflux for 3 hours, and distill under reduced pressure after the reaction is complete to obtain intermediate product 2.

[0014] Furthermore, the ratio of intermediate 1, toluene, boron trifluoride-diethyl ether complex, and 2,3-epoxypropyltrimethylammonium chloride solution is 0.2-0.4 mol: 150-200 mL: 0.05-0.1 g: 90-150 mL;

[0015] Furthermore, the 2,3-epoxypropyltrimethylammonium chloride solution is prepared by mixing 2,3-epoxypropyltrimethylammonium chloride and anhydrous methanol in a volume ratio of 0.23-0.46 mol: 90-150 mL;

[0016] In step A2, intermediate 1 and 2,3-epoxypropyltrimethylammonium chloride undergo a ring-opening reaction, introducing hydroxyl groups into the system and providing reaction conditions for subsequent acylation reactions. The introduced quaternary ammonium salt can be adsorbed onto the negatively charged bacterial cell wall surface, destroying the cell membrane structure, inhibiting bacterial enzyme activity, interfering with the physiological functions of microorganisms, and improving the bactericidal effect.

[0017] Step A3: Mix baicalin and N,N-dimethylformamide (DMF), shake for 15 min to obtain solution 1, then add thionyl chloride to intermediate product 2 solution, react in an ice-water bath for 30 min, then return to room temperature, add solution 1, react at room temperature for 10 h, after the reaction is completed, purify, centrifuge, filter, freeze dry to obtain modified antibacterial agent;

[0018] Furthermore, the volume ratio of baicalin, DMF, thionyl chloride, and intermediate product 2 solution is 0.1-0.2 mol : 300-400 mL : 0.15-0.3 mol : 100-180 mL;

[0019] Furthermore, the intermediate product 2 solution is prepared by mixing intermediate product 2 and DMF in a volume ratio of 0.15-0.3 mol: 100-180 mL;

[0020] In step A3, baicalin and intermediate product 2 undergo an esterification reaction. Baicalin has excellent antibacterial properties and broad-spectrum antibacterial activity. It achieves the purpose of inhibiting and killing bacteria by changing cell membrane permeability, inhibiting the production of enzymes related to bacterial survival and reproduction, and inhibiting DNA replication. It works synergistically with benzisothiazolinone and quaternary ammonium salts, resulting in a broader antibacterial spectrum. It also has the advantages of high efficiency in killing bacteria, long-lasting antibacterial effect, and low biotoxicity.

[0021] The modified flame retardant is prepared by the following steps:

[0022] Step B1: Mix 2-aminothiazole, vanillin and ethanol, stir and reflux at 60°C for 5 hours, then add phosphorous acid solution dropwise. After the addition is complete, adjust the temperature to 75°C, stir and reflux for 8 hours, cool to room temperature, filter, wash and dry to obtain thiazole derivative.

[0023] Furthermore, the volume ratio of 2-aminothiazole, vanillin, ethanol, and phosphorous acid solution is 0.1-0.2 mol : 0.1-0.2 mol : 300-400 mL : 80-150 mL;

[0024] Furthermore, the phosphorous acid solution is prepared by mixing phosphorous acid and ethanol in a volume ratio of 0.1-0.2 mol: 80-150 mL;

[0025] In step B1, 2-aminothiazole and vanillin first undergo a Schiff base reaction, and then an addition reaction with phosphorous acid, introducing the phenolic hydroxyl group into the system and providing reaction conditions for the subsequent substitution reaction. The thiazole structure contains nitrogen and sulfur elements, and the reaction with phosphorous acid introduces phosphorus elements. When it decomposes at high temperature, it releases nitrogen and phosphorus-containing free radical scavengers, interrupting the combustion chain reaction, and generating non-flammable gas, thus diluting the concentration of flammable gas.

[0026] Step B2: Mix the thiazole derivative and DMF, add epichlorohydrin, stir for 10 min, then add tetrabutylammonium bromide, react at 80°C for 2 h under a nitrogen atmosphere, then lower the temperature to 50°C, add 25 wt% sodium hydroxide aqueous solution dropwise, stir and react for 3 h, after the reaction is complete, wash, rotary evaporate, and vacuum dry to obtain the epoxythiazole derivative.

[0027] Furthermore, the ratio of the amount of thiazole derivative, DMF, epichlorohydrin, tetrabutylammonium bromide, and sodium hydroxide aqueous solution is 0.06-0.08 mol: 60-80 mL: 1.2-1.6 mol: 0.01-0.018 mol: 20-30 g;

[0028] In step B2, the thiazole derivative and epichlorohydrin undergo a substitution reaction, introducing an epoxy group into the system and providing reaction conditions for the subsequent ring-opening addition reaction.

[0029] Step B3: Mix the epoxythiazole derivative and boric acid, add p-toluenesulfonic acid, use DMF as solvent, react at 125°C for 4 hours, extract with ethyl acetate and deionized water, and vacuum dry to obtain the modified flame retardant.

[0030] Furthermore, the ratio of the amount of epoxythiazole derivative, boric acid, p-toluenesulfonic acid, DMF, ethyl acetate and deionized water is 0.04-0.06 mol: 0.04-0.06 mol: 0.08-0.12 g: 80-120 mL: 300 mL: 300 mL;

[0031] In step B3, the epoxy-thiazole derivative and boric acid undergo a ring-opening addition reaction. The introduction of boron allows the boron-containing flame retardant to form a glassy protective layer during combustion, effectively isolating heat and oxygen transfer. Simultaneously, it works synergistically with the thiazole ring and phosphorus, providing a dual-layer flame retardant effect of both gas-phase free radical capture and condensed-phase char formation, thus improving flame retardant efficiency.

[0032] A method for preparing an antibacterial modified PC / ABS composite material includes the following steps:

[0033] Step S1: Weigh the raw materials according to the weight parts, and add ABS resin, PC resin, modified antibacterial agent, modified flame retardant, toughening agent, antioxidant, polyethylene wax and maleic anhydride grafted polyethylene into the high-speed mixer in sequence. Set the speed to 500-1000 rpm, mix for 4-10 minutes, and discharge to obtain the mixture.

[0034] Step S2: The mixture is fed into the hopper of a twin-screw extruder. A high-shear screw combination is selected, the screw speed of the extruder is 400-550 r / min, the main feed is 15-25 Hz, the vacuum degree is -0.04 MPa, and the temperature is 235-270℃. After extrusion granulation, the pelletizer speed is 700-900 rpm to obtain an antibacterial modified PC / ABS composite material.

[0035] The beneficial effects of this invention are:

[0036] The antibacterial modified PC / ABS composite material of this invention can be widely used in the manufacturing of medical devices, home building materials, office equipment, public infrastructure, and other fields. Using this composite material in product manufacturing endows products with long-lasting and broad-spectrum antibacterial protection. The modified antibacterial agent of this invention can effectively kill common pathogenic microorganisms such as Escherichia coli and Staphylococcus aureus, exhibiting stable and long-lasting antibacterial performance. It can effectively inhibit the growth of microorganisms on the material surface, significantly reducing the risk of cross-contamination in daily use and public applications. Simultaneously, this invention, through the modification of flame retardants, can simultaneously exert a dual effect of gas-phase flame retardancy and condensed-phase charring during the material's heating and combustion processes, meeting the stringent UL94 V-0 flame retardant rating requirements. Compared with existing technologies, this invention, through the directional modification design of antibacterial agents and flame retardants, endows materials with the dual core functions of highly efficient antibacterial and excellent flame retardant properties, while retaining the excellent mechanical properties of the PC / ABS substrate itself. It avoids the common problem that the addition of additives in traditional functional modification can easily lead to serious deterioration of the mechanical properties of materials. It combines functionality, safety and economy, and has broad market application and industrialization prospects.

[0037] The modified antibacterial agent of this invention first undergoes a nucleophilic substitution reaction with 1,2-benzisothiazolinone and chloroethanol. The introduced benzisothiazolinone exhibits high antibacterial activity. Intracellular target proteins or glutathione readily react with the nitrogen-sulfur bonds in the molecular structure, leading to bond breakage, heterocyclic opening, and the formation of disulfides. These disulfides interfere with enzymatic processes, causing cellular dysfunction and ultimately bacterial death. Subsequently, a ring-opening reaction occurs with 2,3-epoxypropyltrimethylammonium chloride. The introduced quaternary ammonium salt can adsorb onto the negatively charged bacterial cell wall surface, disrupting the cell membrane structure, inhibiting bacterial enzyme activity, interfering with microbial physiological functions, and enhancing the bactericidal effect. Finally, through esterification, the introduced baicalin exhibits excellent antibacterial properties and broad-spectrum antibacterial activity. It achieves its antibacterial and bactericidal effects by altering cell membrane permeability, inhibiting the production of enzymes related to bacterial survival and reproduction, and inhibiting DNA replication. In synergistic effect with benzisothiazolinone and quaternary ammonium salts, it has a broader antibacterial spectrum and also possesses the advantages of high-efficiency bactericidal activity, long-lasting antibacterial effect, and low biotoxicity.

[0038] The modified flame retardant of this invention first undergoes a Schiff base reaction with 2-aminothiazole and vanillin, followed by an addition reaction with phosphorous acid. The thiazole structure contains nitrogen and sulfur elements, and the reaction with phosphorous acid introduces phosphorus. Upon decomposition at high temperatures, it releases nitrogen- and phosphorus-containing free radical scavengers, interrupting the combustion chain reaction and simultaneously generating non-flammable gases, diluting the concentration of flammable gases. Subsequently, it undergoes a substitution reaction with epichlorohydrin, introducing epoxy groups. Finally, it undergoes a ring-opening addition reaction with boric acid, introducing boron. The boron-containing flame retardant forms a glassy protective layer during combustion, effectively isolating heat and oxygen transfer. Simultaneously, it works synergistically with the thiazole ring and phosphorus, possessing a dual flame-retardant effect of gas-phase free radical scavenging and condensed-phase dense char formation, thus improving flame-retardant efficiency. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0040] Example 1: The modified antibacterial agent was prepared by the following steps:

[0041] Step A1: Mix 1,2-benzisothiazol-3-one, 8wt% sodium hydroxide aqueous solution, and chloroethanol in a microwave reactor and stir at 75°C for 1 hour. After the reaction is complete, distill under reduced pressure, add dichloromethane and stir, dry, filter, distill under reduced pressure, and recrystallize to obtain the intermediate product 1,1,2-benzisothiazol-3-one. The ratio of sodium hydroxide aqueous solution, chloroethanol, and dichloromethane is 0.4 mol: 100 mL: 0.1 mol: 300 mL.

[0042] Step A2: Mix intermediate product 1 and toluene, stir and heat to 80℃, add boron trifluoride-diethyl ether complex, and dropwise add 2,3-epoxypropyltrimethylammonium chloride solution. After the addition is complete, reflux for 3 hours. After the reaction is complete, distill under reduced pressure to obtain intermediate product 2. The ratio of intermediate product 1, toluene, boron trifluoride-diethyl ether complex and 2,3-epoxypropyltrimethylammonium chloride solution is 0.2 mol: 150 mL: 0.05 g: 90 mL. The 2,3-epoxypropyltrimethylammonium chloride solution is prepared by mixing 2,3-epoxypropyltrimethylammonium chloride and anhydrous methanol at a ratio of 0.23 mol: 90 mL.

[0043] Step A3: Mix baicalin and DMF, shake for 15 min to obtain solution 1, then add thionyl chloride to intermediate product 2 solution, react in an ice-water bath for 30 min, then return to room temperature, add solution 1, react at room temperature for 10 h, after the reaction is complete, purify, centrifuge, filter, and freeze dry to obtain the modified antibacterial agent. The ratio of baicalin, DMF, thionyl chloride and intermediate product 2 solution is 0.1 mol: 300 mL: 0.15 mol: 100 mL. Intermediate product 2 solution is prepared by mixing intermediate product 2 and DMF in a ratio of 0.15 mol: 100 mL.

[0044] The modified flame retardant is prepared by the following steps:

[0045] Step B1: Mix 2-aminothiazole, vanillin, and ethanol, and reflux at 60°C for 5 hours. Then, add phosphorous acid solution dropwise. After the addition is complete, adjust the temperature to 75°C, reflux for 8 hours, cool to room temperature, filter, wash, and dry to obtain the thiazole derivative. The ratio of 2-aminothiazole, vanillin, ethanol, and phosphorous acid solution is 0.1 mol: 0.1 mol: 300 mL: 80 mL. The phosphorous acid solution is prepared by mixing phosphorous acid and ethanol at a ratio of 0.1 mol: 80 mL.

[0046] Step B2: Mix the thiazole derivative and DMF, add epichlorohydrin, stir for 10 min, then add tetrabutylammonium bromide, and react at 80°C for 2 h under a nitrogen atmosphere. Then, lower the temperature to 50°C, add 25 wt% sodium hydroxide aqueous solution dropwise, and stir for 3 h. After the reaction is complete, wash, rotary evaporate, and vacuum dry to obtain the epoxy thiazole derivative. The ratio of thiazole derivative, DMF, epichlorohydrin, tetrabutylammonium bromide, and sodium hydroxide aqueous solution is 0.06 mol: 60 mL: 1.2 mol: 0.01 mol: 20 g.

[0047] Step B3: Mix the epoxythiazole derivative and boric acid, add p-toluenesulfonic acid, use DMF as solvent, react at 125℃ for 4 h, extract with ethyl acetate and deionized water, and vacuum dry to obtain the modified flame retardant. The ratio of epoxythiazole derivative, boric acid, p-toluenesulfonic acid, DMF, ethyl acetate and deionized water is 0.04 mol: 0.04 mol: 0.08 g: 80 mL: 300 mL: 300 mL.

[0048] Example 2: The modified antibacterial agent was prepared by the following steps:

[0049] Step A1: Mix 1,2-benzisothiazol-3-one, 8wt% sodium hydroxide aqueous solution, and chloroethanol in a microwave reactor and stir at 75°C for 1 hour. After the reaction is complete, distill under reduced pressure, add dichloromethane and stir, dry, filter, distill under reduced pressure, and recrystallize to obtain the intermediate product 1,1,2-benzisothiazol-3-one. The ratio of sodium hydroxide aqueous solution, chloroethanol, and dichloromethane is 0.5 mol: 125 mL: 0.125 mol: 350 mL.

[0050] Step A2: Mix intermediate product 1 and toluene, stir and heat to 80℃, add boron trifluoride-diethyl ether complex, and dropwise add 2,3-epoxypropyltrimethylammonium chloride solution. After the addition is complete, reflux for 3 hours. After the reaction is complete, distill under reduced pressure to obtain intermediate product 2. The ratio of intermediate product 1, toluene, boron trifluoride-diethyl ether complex and 2,3-epoxypropyltrimethylammonium chloride solution is 0.3 mol: 175 mL: 0.055 g: 120 mL. The 2,3-epoxypropyltrimethylammonium chloride solution is prepared by mixing 2,3-epoxypropyltrimethylammonium chloride and anhydrous methanol at a ratio of 0.345 mol: 120 mL.

[0051] Step A3: Mix baicalin and DMF, shake for 15 min to obtain solution 1, then add thionyl chloride to intermediate product 2 solution, react in an ice-water bath for 30 min, then return to room temperature, add solution 1, react at room temperature for 10 h, after the reaction is complete, purify, centrifuge, filter, and freeze dry to obtain the modified antibacterial agent. The ratio of baicalin, DMF, thionyl chloride and intermediate product 2 solution is 0.15 mol: 350 mL: 0.225 mol: 140 mL. Intermediate product 2 solution is prepared by mixing intermediate product 2 and DMF in a ratio of 0.225 mol: 140 mL.

[0052] The modified flame retardant is prepared by the following steps:

[0053] Step B1: Mix 2-aminothiazole, vanillin, and ethanol, and reflux at 60°C for 5 hours. Then, add phosphorous acid solution dropwise. After the addition is complete, adjust the temperature to 75°C, reflux for 8 hours, cool to room temperature, filter, wash, and dry to obtain the thiazole derivative. The ratio of 2-aminothiazole, vanillin, ethanol, and phosphorous acid solution is 0.15 mol: 0.15 mol: 350 mL: 115 mL. The phosphorous acid solution is prepared by mixing phosphorous acid and ethanol at a ratio of 0.15 mol: 115 mL.

[0054] Step B2: Mix the thiazole derivative and DMF, add epichlorohydrin, stir for 10 min, then add tetrabutylammonium bromide, and react at 80°C for 2 h under a nitrogen atmosphere. Then, lower the temperature to 50°C, add 25 wt% sodium hydroxide aqueous solution dropwise, and stir for 3 h. After the reaction is complete, wash, rotary evaporate, and vacuum dry to obtain the epoxy thiazole derivative. The ratio of thiazole derivative, DMF, epichlorohydrin, tetrabutylammonium bromide, and sodium hydroxide aqueous solution is 0.07 mol: 70 mL: 1.4 mol: 0.014 mol: 25 g.

[0055] Step B3: Mix the epoxythiazole derivative and boric acid, add p-toluenesulfonic acid, use DMF as solvent, react at 125℃ for 4 hours, extract with ethyl acetate and deionized water, and vacuum dry to obtain the modified flame retardant. The ratio of epoxythiazole derivative, boric acid, p-toluenesulfonic acid, DMF, ethyl acetate and deionized water is 0.05mol:0.05mol:0.1g:100mL:300mL:300mL.

[0056] Example 3: The modified antibacterial agent was prepared by the following steps:

[0057] Step A1: Mix 1,2-benzisothiazol-3-one, 8wt% sodium hydroxide aqueous solution, and chloroethanol in a microwave reactor and stir at 75°C for 1 hour. After the reaction is complete, distill under reduced pressure, add dichloromethane and stir, dry, filter, distill under reduced pressure, and recrystallize to obtain the intermediate product 1,1,2-benzisothiazol-3-one. The ratio of sodium hydroxide aqueous solution, chloroethanol, and dichloromethane is 0.6 mol: 150 mL: 0.15 mol: 400 mL.

[0058] Step A2: Mix intermediate product 1 and toluene, stir and heat to 80℃, add boron trifluoride-diethyl ether complex, and dropwise add 2,3-epoxypropyltrimethylammonium chloride solution. After the addition is complete, reflux for 3 hours. After the reaction is complete, distill under reduced pressure to obtain intermediate product 2. The ratio of intermediate product 1, toluene, boron trifluoride-diethyl ether complex and 2,3-epoxypropyltrimethylammonium chloride solution is 0.4 mol: 200 mL: 0.1 g: 150 mL. The 2,3-epoxypropyltrimethylammonium chloride solution is prepared by mixing 2,3-epoxypropyltrimethylammonium chloride and anhydrous methanol at a ratio of 0.46 mol: 150 mL.

[0059] Step A3: Mix baicalin and DMF, shake for 15 min to obtain solution 1, then add thionyl chloride to intermediate product 2 solution, react in an ice-water bath for 30 min, then return to room temperature, add solution 1, react at room temperature for 10 h, after the reaction is complete, purify, centrifuge, filter, and freeze dry to obtain the modified antibacterial agent. The volume ratio of baicalin, DMF, thionyl chloride and intermediate product 2 solution is 0.2 mol: 400 mL: 0.3 mol: 180 mL. Intermediate product 2 solution is prepared by mixing intermediate product 2 and DMF in a volume ratio of 0.3 mol: 180 mL.

[0060] The modified flame retardant is prepared by the following steps:

[0061] Step B1: Mix 2-aminothiazole, vanillin, and ethanol, and reflux at 60°C for 5 hours. Then, add phosphorous acid solution dropwise. After the addition is complete, adjust the temperature to 75°C, reflux for 8 hours, cool to room temperature, filter, wash, and dry to obtain the thiazole derivative. The ratio of 2-aminothiazole, vanillin, ethanol, and phosphorous acid solution is 0.2 mol: 0.2 mol: 400 mL: 150 mL. The phosphorous acid solution is prepared by mixing phosphorous acid and ethanol at a ratio of 0.2 mol: 150 mL.

[0062] Step B2: Mix the thiazole derivative and DMF, add epichlorohydrin, stir for 10 min, then add tetrabutylammonium bromide, and react at 80°C for 2 h under a nitrogen atmosphere. After that, lower the temperature to 50°C, add 25 wt% sodium hydroxide aqueous solution dropwise, and stir for 3 h. After the reaction is complete, wash, rotary evaporate, and vacuum dry to obtain the epoxy thiazole derivative. The ratio of thiazole derivative, DMF, epichlorohydrin, tetrabutylammonium bromide, and sodium hydroxide aqueous solution is 0.08 mol: 80 mL: 1.6 mol: 0.018 mol: 30 g.

[0063] Step B3: Mix the epoxythiazole derivative and boric acid, add p-toluenesulfonic acid, use DMF as solvent, react at 125℃ for 4 h, extract with ethyl acetate and deionized water, and vacuum dry to obtain the modified flame retardant. The ratio of epoxythiazole derivative, boric acid, p-toluenesulfonic acid, DMF, ethyl acetate and deionized water is 0.06 mol: 0.06 mol: 0.12 g: 120 mL: 300 mL: 300 mL.

[0064] Example 4: A method for preparing an antibacterial modified PC / ABS composite material, comprising the following steps:

[0065] 30 parts ABS resin, 10 parts PC resin, 1 part modified antibacterial agent prepared in Example 1, 2 parts modified flame retardant prepared in Example 1, 3 parts methyl methacrylate-butadiene-styrene copolymer, 0.5 parts antioxidant 1076, 0.5 parts polyethylene wax, and 0.5 parts maleic anhydride grafted polyethylene.

[0066] Step S1: Weigh the raw materials according to the weight parts, and add ABS resin, PC resin, modified antibacterial agent prepared in Example 1, modified flame retardant prepared in Example 1, methyl methacrylate-butadiene-styrene copolymer, antioxidant 1076, polyethylene wax and maleic anhydride grafted polyethylene into a high-speed mixer in sequence. Set the speed to 500 rpm, mix for 4 min, and discharge to obtain a mixture.

[0067] Step S2: The mixture is fed into the hopper of a twin-screw extruder. A high-shear screw combination is selected, the screw speed of the extruder is 400 r / min, the main feed is 15 Hz, the vacuum degree is -0.04 MPa, and the temperature is 235 ℃. After extrusion granulation, the pelletizer speed is 700 rpm to obtain an antibacterial modified PC / ABS composite material.

[0068] Example 5: A method for preparing an antibacterial modified PC / ABS composite material, comprising the following steps:

[0069] 50 parts ABS resin, 30 parts PC resin, 2 parts modified antibacterial agent prepared in Example 2, 3 parts modified flame retardant prepared in Example 2, 5 parts methyl methacrylate-butadiene-styrene copolymer, 0.5 parts antioxidant 168, 1 part polyethylene wax, and 1 part maleic anhydride grafted polyethylene.

[0070] Step S1: Weigh the raw materials according to the weight parts, and add ABS resin, PC resin, modified antibacterial agent prepared in Example 2, modified flame retardant prepared in Example 2, methyl methacrylate-butadiene-styrene copolymer, antioxidant 168, polyethylene wax and maleic anhydride grafted polyethylene into a high-speed mixer in sequence. Set the speed to 800 rpm, mix for 8 minutes, and discharge to obtain a mixture.

[0071] Step S2: The mixture is fed into the hopper of a twin-screw extruder. A high-shear screw combination is selected, the screw speed of the extruder is 500 r / min, the main feed is 20 Hz, the vacuum degree is -0.04 MPa, and the temperature is 250℃. After extrusion granulation, the pelletizer speed is 800 rpm to obtain antibacterial modified PC / ABS composite material.

[0072] Example 6: A method for preparing an antibacterial modified PC / ABS composite material, comprising the following steps:

[0073] 60 parts ABS resin, 50 parts PC resin, 3 parts modified antibacterial agent prepared in Example 3, 4 parts modified flame retardant prepared in Example 3, 6 parts methyl methacrylate-butadiene-styrene copolymer, 0.5 parts antioxidant 1076, 0.5 parts antioxidant 168, 1 part polyethylene wax, and 1.5 parts maleic anhydride grafted polyethylene.

[0074] Step S1: Weigh the raw materials according to the weight parts, and add ABS resin, PC resin, modified antibacterial agent prepared in Example 3, modified flame retardant prepared in Example 3, methyl methacrylate-butadiene-styrene copolymer, antioxidant, polyethylene wax and maleic anhydride grafted polyethylene into a high-speed mixer in sequence. Set the speed to 1000 rpm, mix for 10 min, and discharge to obtain a mixture.

[0075] Step S2: The mixture is fed into the hopper of a twin-screw extruder. A high-shear screw combination is selected, the screw speed of the extruder is 550 r / min, the main feed is 25 Hz, the vacuum degree is -0.04 MPa, and the temperature is 270℃. After extrusion granulation, the pelletizer speed is 900 rpm to obtain an antibacterial modified PC / ABS composite material.

[0076] Comparative Example 1: This comparative example is a PC / ABS composite material. The difference between this example and Example 6 is that cetyltrimethylammonium bromide is used instead of the modified antibacterial agent prepared in Example 3. All other aspects are the same.

[0077] Comparative Example 2: This comparative example is a PC / ABS composite material. The difference between this example and Example 6 is that magnesium hydroxide is used instead of the modified flame retardant prepared in Example 3. All other aspects are the same.

[0078] Comparative Example 3: This comparative example is a PC / ABS composite material. The difference between this example and Example 6 is that cetyltrimethylammonium bromide is used instead of the modified antibacterial agent prepared in Example 3, and magnesium hydroxide is used instead of the modified flame retardant prepared in Example 3. All other aspects are the same.

[0079] The composite materials prepared in Examples 4-6 and Comparative Examples 1-3 were subjected to performance tests:

[0080] Tensile property testing: according to ASTM D638 standard;

[0081] Bending performance test: according to ASTM D790 standard;

[0082] Cantilever beam notched impact test: according to ASTM D256 standard;

[0083] Antibacterial performance test: The material was left to stand overnight under natural conditions, and Escherichia coli and Staphylococcus aureus, which are common bacteria in this field, were used as the observation objects to test the antibacterial rate;

[0084] Flame retardant performance: in accordance with UL 94 standard;

[0085] Limiting oxygen index: Tested according to GB 2406.2-2009 standard.

[0086] The test results are shown in Table 1:

[0087] Table 1: Performance Test Results

[0088]

[0089] As shown in Table 1, the PC / ABS composite material prepared by this invention possesses excellent mechanical properties. In the examples, the tensile strength of the materials is above 57 MPa, the flexural strength is above 71 MPa, and the notched impact strength is above 580 J / m. Examples 6 and 1 (Comparative Example 1) demonstrate that the modified antibacterial agent prepared by this invention exhibits excellent antibacterial properties. Examples 6 and 2 (Comparative Example 2) show that the modified flame retardant prepared by this invention improves the flame retardant rating of the material without affecting its mechanical properties. This demonstrates that the PC / ABS composite material prepared by this invention possesses highly efficient antibacterial properties, excellent flame retardant properties, and stable mechanical properties.

[0090] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. An antibacterial modified PC / ABS composite material, characterized in that, The raw materials include the following parts by weight: 30-60 parts ABS resin, 10-50 parts PC resin, 1-3 parts modified antibacterial agent, 2-4 parts modified flame retardant, 3-6 parts toughening agent, 0.5-1 part antioxidant, 0.5-1 part polyethylene wax, and 0.5-1.5 parts maleic anhydride grafted polyethylene. The modified antibacterial agent is prepared by the following steps: Step A1: Mix 1,2-benzisothiazol-3-one, 8wt% sodium hydroxide aqueous solution and chloroethanol, place in a microwave reactor, stir and react at 75℃ for 1h. After the reaction is completed, distill under reduced pressure, add dichloromethane and stir, dry, filter, distill under reduced pressure and recrystallize to obtain intermediate product 1. Step A2: Mix intermediate product 1 with toluene, stir and heat to 80°C, add boron trifluoride-diethyl ether complex, add 2,3-epoxypropyltrimethylammonium chloride solution dropwise, after the addition is complete, reflux for 3 hours, and distill under reduced pressure after the reaction is complete to obtain intermediate product 2. Step A3: Mix baicalin and DMF, shake for 15 min to obtain solution 1, then add thionyl chloride to intermediate product 2 solution, react in an ice-water bath for 30 min, then restore to room temperature, add solution 1, react at room temperature for 10 h, after the reaction is completed, purify, centrifuge, filter, freeze dry to obtain modified antibacterial agent.

2. The antibacterial modified PC / ABS composite material according to claim 1, characterized in that, In step A1, the ratio of 1,2-benzisothiazol-3-one, sodium hydroxide aqueous solution, chloroethanol, and dichloromethane is 0.4-0.6 mol: 100-150 mL: 0.1-0.15 mol: 300-400 mL.

3. The antibacterial modified PC / ABS composite material according to claim 1, characterized in that, In step A2, the ratio of intermediate product 1, toluene, boron trifluoride-diethyl ether complex, and 2,3-epoxypropyltrimethylammonium chloride solution is 0.2-0.4 mol: 150-200 mL: 0.05-0.1 g: 90-150 mL. The 2,3-epoxypropyltrimethylammonium chloride solution is prepared by mixing 2,3-epoxypropyltrimethylammonium chloride and anhydrous methanol at a ratio of 0.23-0.46 mol: 90-150 mL.

4. The antibacterial modified PC / ABS composite material according to claim 1, characterized in that, In step A3, the ratio of baicalin, DMF, thionyl chloride, and intermediate product 2 solution is 0.1-0.2 mol: 300-400 mL: 0.15-0.3 mol: 100-180 mL. Intermediate product 2 solution is prepared by mixing intermediate product 2 and DMF in a ratio of 0.15-0.3 mol: 100-180 mL.

5. The antibacterial modified PC / ABS composite material according to claim 1, characterized in that, The modified flame retardant is prepared by the following steps: Step B1: Mix 2-aminothiazole, vanillin and ethanol, stir and reflux at 60°C for 5 hours, then add phosphorous acid solution dropwise. After the addition is complete, adjust the temperature to 75°C, stir and reflux for 8 hours, cool to room temperature, filter, wash and dry to obtain thiazole derivative. Step B2: Mix the thiazole derivative and DMF, add epichlorohydrin, stir for 10 min, then add tetrabutylammonium bromide, react at 80°C for 2 h under a nitrogen atmosphere, then lower the temperature to 50°C, add 25 wt% sodium hydroxide aqueous solution dropwise, stir and react for 3 h, after the reaction is complete, wash, rotary evaporate, and vacuum dry to obtain the epoxythiazole derivative. Step B3: Mix the epoxythiazole derivative and boric acid, add p-toluenesulfonic acid, use DMF as solvent, react at 125°C for 4 hours, extract with ethyl acetate and deionized water, and vacuum dry to obtain the modified flame retardant.

6. The antibacterial modified PC / ABS composite material according to claim 5, characterized in that, In step B1, the ratio of 2-aminothiazole, vanillin, ethanol, and phosphorous acid solution is 0.1-0.2 mol: 0.1-0.2 mol: 300-400 mL: 80-150 mL. The phosphorous acid solution is prepared by mixing phosphorous acid and ethanol in a ratio of 0.1-0.2 mol: 80-150 mL.

7. The antibacterial modified PC / ABS composite material according to claim 5, characterized in that, In step B2, the ratio of the amounts of thiazole derivative, DMF, epichlorohydrin, tetrabutylammonium bromide, and sodium hydroxide aqueous solution is 0.06-0.08 mol: 60-80 mL: 1.2-1.6 mol: 0.01-0.018 mol: 20-30 g.

8. The antibacterial modified PC / ABS composite material according to claim 5, characterized in that, In step B3, the ratio of the amount of epoxythiazole derivative, boric acid, p-toluenesulfonic acid, DMF, ethyl acetate and deionized water is 0.04-0.06 mol: 0.04-0.06 mol: 0.08-0.12 g: 80-120 mL: 300 mL: 300 mL.

9. The antibacterial modified PC / ABS composite material according to claim 1, characterized in that, The toughening agent is a methyl methacrylate-butadiene-styrene copolymer, and the antioxidant is at least one of antioxidant 1076 and antioxidant 168.

10. A method for preparing the antibacterial modified PC / ABS composite material according to any one of claims 1-9, characterized in that, The antibacterial modified PC / ABS composite material is prepared by the following steps: Step S1: Weigh the raw materials according to the weight parts, and add ABS resin, PC resin, modified antibacterial agent, modified flame retardant, toughening agent, antioxidant, polyethylene wax and maleic anhydride grafted polyethylene into the high-speed mixer in sequence. Set the speed to 500-1000 rpm, mix for 4-10 minutes, and discharge to obtain the mixture. Step S2: The mixture is fed into the hopper of a twin-screw extruder. A high-shear screw combination is selected, the screw speed of the extruder is 400-550 r / min, the main feed is 15-25 Hz, the vacuum degree is -0.04 MPa, and the temperature is 235-270℃. After extrusion granulation, the pelletizer speed is 700-900 rpm to obtain an antibacterial modified PC / ABS composite material.

Images