Antibacterial flame-retardant polypropylene composite fiber and preparation method thereof

Abstract

The present invention relates to the technical field of composite materials, and in particular to an antibacterial and flame-retardant polypropylene composite fiber and a preparation method thereof. A metal-organic framework material and CeO2 are mixed and stirred evenly, ball-milled at a speed of 100-200 rpm for 6-8 h, and screened to obtain MOFs@CeO2 powder; 90-92 wt% of polypropylene, 2.0-6.0 wt% of MOFs@CeO2, and 2-6 wt% of melamine borate are taken and placed in a twin-screw extruder with a rotation speed of 20-40 Hz and a heating temperature of 200-230 °C for melt mixing, and then extruded into a spinning box with a temperature of 220-230 °C and a side blowing air volume of 15-40 m 3 / min for spinning. After oiling by an oiling system and drawing and winding by a winding machine, an antibacterial and flame-retardant polypropylene composite fiber is obtained. The antibacterial and flame-retardant polypropylene composite fiber of the present invention has excellent flame-retardant performance and antibacterial performance. Its limiting oxygen index can reach 30.6%, and the vertical burning test (UL94) can reach V-0 level; the antibacterial rates against Escherichia coli, Staphylococcus aureus, and Candida albicans can all reach more than 99.9%, and the antibacterial rate still reaches more than 98% after being washed 100 times.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to an antibacterial flame-retardant polypropylene composite fiber and a preparation method thereof. Background Art

[0002] Metal organic framework materials (MOFs) are a type of porous materials formed by the assembly of metal ions or metal atom clusters and organic ligands. They are widely used in catalysis, gas adsorption and separation, sensor detection, energy storage, and biomedicine. In recent years, MOFs and their derivatives have shown unique advantages in the fields of flame retardancy and antibacterial. The Chinese invention patent with application publication number CN109320910A discloses a method for preparing a metal organic framework structure encapsulated ammonium polyphosphate flame retardant. The invention uses a metal organic framework structure to seal the active points of ammonium polyphosphate, which can effectively reduce the polarity and hydrophilicity of the material, improve its compatibility and dispersibility with organic high molecular polymers, and at the same time has a catalytic carbonization effect, thereby improving the flame retardant efficiency of ammonium polyphosphate. The Chinese invention patent with application publication number CN109820000A discloses a method for preparing a MOFs-loaded nanosilver antibacterial material. The invention avoids the agglomeration of silver nanoparticles by attaching silver nanoparticles to the surface, skeleton and pores of MOFs, thereby achieving efficient antibacterial effect.

[0003] Polypropylene has excellent comprehensive properties and is cheap. It is widely used in textiles and clothing, interior decoration, floor coverings, health care, and automotive interiors. It is one of the five general-purpose plastics with the fastest development, largest output, and widest application. However, the limiting oxygen index (LOI) of polypropylene is relatively low, only about 18%, and it is easy to burn. In the combustion process, it will also produce a lot of smoke, causing great harm to the environment and people’s production and property. In addition, with the improvement of living standards and the promotion of influenza, people have higher and higher requirements for healthy living and safety protection, and antibacterial products are becoming more and more popular. Therefore, it is in line with the market development trend to modify the flame retardant and antibacterial properties of polypropylene fibers and related products to prepare composite fibers with integrated flame retardant and antibacterial functions, and it has broad application prospects. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an antibacterial flame retardant polypropylene composite fiber and a preparation method thereof. The preparation method is simple, and the prepared antibacterial flame retardant polypropylene composite fiber has excellent flame retardant and antibacterial properties.

[0005] The present invention solves the above technical problems by the following technical means:

[0006] The first aspect of the present invention provides an antibacterial flame-retardant polypropylene composite fiber, comprising the following raw materials:

[0007] Polypropylene 90-92wt%, MOFs@CeO 2 2.0~6.0wt%, melamine borate 2~6wt%.

[0008] In combination with the first aspect, in some optional embodiments, the antibacterial flame retardant polypropylene composite fiber includes the following raw materials:

[0009] Polypropylene 92wt%, MOFs@CeO 2 4.0wt%, melamine borate 4wt%.

[0010] In combination with the first aspect, in some optional embodiments, the MOFs@CeO 2 Metal-organic framework materials and CeO 2 The metal organic framework material and CeO 2 The molar ratio is 1:2.

[0011] The second aspect of the present invention provides a method for preparing an antibacterial flame-retardant polypropylene composite fiber, comprising the following steps:

[0012] Preparation of MOFs@CeO 2 , metal organic framework materials and CeO 2 The mixture was stirred evenly, placed in a ball mill, and ball milled at 100-200 rpm for 6-8 h, and MOFs@CeO was obtained by sieving. 2 powder;

[0013] Melt spinning, take 90-92wt% polypropylene, MOFs@CeO 2 2.0-6.0wt%, melamine borate 2-6wt%, placed in a twin-screw extruder with a screw speed of 20-40Hz and a screw heating temperature of 200-230°C for melt mixing, extruded at a temperature of 220-230°C and a side blowing air volume of 15-40m 3 The fiber is spun in a spinning box at a speed of 2000 to 4000 rpm, and the antibacterial and flame-retardant polypropylene composite fiber is obtained after oiling by an oiling system and drawing and winding by a winder. The oiling rate is 2 to 6 wt % and the speed of the winder is 2000 to 4000 rpm.

[0014] In conjunction with the second aspect, in some optional embodiments, the preparation method of the metal organic framework material is as follows:

[0015] Add soluble nitrate into deionized water and stir for 10 to 15 minutes, which is recorded as solution A; add 2-methylimidazole and NaOH into deionized water and stir for 10 to 15 minutes, which is recorded as solution B; add solution B into solution A under stirring, then stir magnetically at 20 to 80° C. for 30 to 60 minutes and then stand for 12 to 24 hours, collect the precipitate and dry it at 60 to 100° C. for 4 to 24 hours to obtain a metal organic framework material.

[0016] In combination with the second aspect, in some optional embodiments, the molar volume ratio of the soluble nitrate, 2-methylimidazole, NaOH, and deionized water is 10 mmol:20 mmol:2.5 mmol:60 mL.

[0017] In combination with the second aspect, in some optional embodiments, the soluble metal salt is one of zinc nitrate hexahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate, and iron nitrate nonahydrate.

[0018] In conjunction with the second aspect, in some optional embodiments, the CeO 2 The preparation method is as follows:

[0019] The cerium nitrate hexahydrate and sodium hydroxide were weighed and mixed, and ultrasonically dispersed in deionized water and stirred at room temperature for 3 to 6 hours to obtain a purple suspension; the purple suspension was centrifuged at 2000 to 8000 rpm for 10 to 20 minutes, and the precipitate was collected and washed with ethanol and deionized water for 3 to 5 times, respectively, and then the precipitate was dried in an oven at 60 to 100° C. for 12 to 24 hours, ground into powder, and calcined at 500 to 800° C. for 3 to 6 hours to obtain CeO 2 powder.

[0020] In combination with the second aspect, in some optional embodiments, the molar volume ratio of the cerium nitrate hexahydrate, sodium hydroxide, and deionized water is 10 mmol:160 mmol:80 mL.

[0021] In combination with the second aspect, in some optional embodiments, the metal organic framework material and CeO 2 The molar ratio is 1:2.

[0022] The flame retardant mechanism of the antibacterial flame retardant polypropylene composite fiber of the present invention is: (1) the metal ion center in MOFs can be catalyzed into carbon to form a dense protective layer during combustion, and its unique porous structure can absorb smoke and toxic gases in the early stage of combustion; (2) MB can promote the formation of thermal stability structures such as POC, BOP and C=C in the material during combustion to improve the thermal stability and carbonization of the material, and form a dense honeycomb skeleton structure to increase the density and expansion of the carbon layer, thereby achieving the purpose of flame retardancy and smoke suppression. The antibacterial mechanism of the antibacterial flame retardant polypropylene composite fiber of the present invention is: (1) MOFs achieves continuous killing of bacteria by continuously and slowly releasing intrinsic metal ions; (2) CeO 2 Under light conditions, it is excited to produce e - , H 2 O 2 、h + , ·O 2- When these active substances come into contact with bacteria, they will change the structure of the bacteria, destroy the intracellular substances of the bacteria, and play an antibacterial and bactericidal role.

[0023] The antibacterial flame-retardant polypropylene composite fiber of the present invention has excellent flame-retardant and antibacterial properties, and its limiting oxygen index can reach 30.6%, and the vertical burning test (UL94) can reach V-0 level; the antibacterial rate of Escherichia coli, Staphylococcus aureus, and Candida albicans can reach more than 99.9%, and the antibacterial rate can still reach more than 98% after washing 100 times. The preparation method of the present invention has simple and easy-to-obtain raw materials, simple operation steps, and can be mass-produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the vertical combustion test process of the antibacterial flame retardant polypropylene composite fiber prepared in Example 1;

[0025] Figure 2 This is the vertical combustion test process of the antibacterial flame retardant polypropylene composite fiber prepared in Example 2;

[0026] Figure 3 This is the vertical combustion test process of the antibacterial flame retardant polypropylene composite fiber prepared in Example 3;

[0027] Figure 4 It is a comparison chart of the inhibition zones of pure PP and the antibacterial flame-retardant polypropylene composite fibers prepared in Examples 1-3. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the following examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The raw materials, equipment or instruments used, if no manufacturer is specified, are all conventional products that can be obtained commercially.

[0030] The present invention synthesizes a series of MOFs materials in an alkaline water system and then reacts with CeO 2 MOFs@CeO 2 The powder is then mixed with MB in a certain proportion and added to polypropylene to prepare an antibacterial flame-retardant polypropylene composite fiber through melt spinning. 2 ) is an n-type semiconductor rare earth metal oxide. After being excited by light, the electrons in the valence band (e - ) is excited to jump to the empty conduction band, and a corresponding hole (h + ). - Has strong reducing properties, + It has strong oxidizing properties and can directly contact with bacteria to kill them. - and h + Can also be respectively with O 2 and OH in water - The reaction generates O which has strong oxidizing properties. 2- , H 2 O 2 and ·OH free radicals. The free radicals react with bacteria to change the structure of the bacteria, thereby inhibiting the growth and reproduction of bacteria, playing an antibacterial and bactericidal role. Melamine borate (MB) is a non-toxic and environmentally friendly intumescent flame retardant with a simple production process. It has good performance in suppressing smoke and improving the thermal stability of polymers.

[0031] The antibacterial flame-retardant polypropylene composite fiber and the preparation method thereof of the present invention are described in detail below through Examples 1-5:

[0032] Example 1

[0033] (1) MOFs synthesis: 2.71 g zinc nitrate hexahydrate was added to 30 mL deionized water and stirred for 15 min, which was recorded as solution A. 1.64 g 2-methylimidazole and 0.1 g NaOH were added to 30 mL deionized water and stirred for 15 min, which was recorded as solution B. Solution B was added to solution A under magnetic stirring. Then, the solution was stirred at 40 °C for 30 min and then allowed to stand for 12 h. The precipitate was collected and dried at 80 °C for 4 h.

[0034] (2) CeO 2 Synthesis: Weigh 4.34g of cerium nitrate hexahydrate and 6.4g of sodium hydroxide, ultrasonically disperse the two in 80mL of deionized water, and then magnetically stir at room temperature for 3h to obtain a purple suspension. The suspension was centrifuged at 3000rpm for 10min to collect the precipitate, and then washed with ethanol and deionized water three times respectively. The precipitate was then dried in an oven at 60℃ for 12h, and finally the dried product was ground into powder and placed in an energy-saving resistance furnace and calcined at 550℃ for 3h to obtain a light yellow CeO 2 powder.

[0035] (3)MOFs@CeO 2 Synthesis: MOFs@CeO was prepared by ball milling 2 , 230 mg MOFs and 344 mg CeO 2 The mixture was mixed evenly, placed in a ball mill under air atmosphere, and ball milled at 100 rpm for 6 h. After the ball milling, the mixture and the small balls were sieved to obtain MOFs@CeO 2 powder.

[0036] (4)MOFs@CeO 2 Preparation of MOFs@CeO / MB / polypropylene composite fibers by melt spinning 2 / MB / polypropylene flame retardant and antibacterial composite fibers. 2wt% MOFs@CeO 2 , 6wt% MB and 92wt% polypropylene chips are melt mixed in a twin-screw extruder and then extruded into a spinning box, and then delivered to a spinning assembly by a metering pump. After oiling by an oiling system and drawing and winding by a winding device, a flame-retardant and antibacterial composite fiber is obtained. In this step, the screw speed is 30Hz, the average temperature of the screw heating zone is 220℃, the spinning box temperature is 225℃, and the side blowing air volume is 22m 3 / min, the oiling rate is 3wt%, and the winding machine speed is 3200rpm.

[0037] Example 2

[0038] (1) MOFs synthesis: 4.365 g of cobalt nitrate hexahydrate was added to 45 mL of deionized water and stirred for 15 min, which was recorded as solution A. 2.46 g of 2-methylimidazole and 0.15 g of NaOH were added to 45 mL of deionized water and stirred for 15 min, which was recorded as solution B. Solution B was added to solution A under magnetic stirring. Then, the solution was stirred at 40 °C for 30 min and then allowed to stand for 12 h. The precipitate was collected and dried at 80 °C for 4 h.

[0039] (2) CeO 2 Synthesis: Weigh 6.51g of cerium nitrate hexahydrate and 9.6g of sodium hydroxide, ultrasonically disperse the two in 120mL of deionized water, and then magnetically stir at room temperature for 3h to obtain a purple suspension. The suspension was centrifuged at 3000rpm for 10min to collect the precipitate, and then washed with ethanol and deionized water three times respectively. The precipitate was then dried in an oven at 60℃ for 12h, and finally the dried product was ground into powder and placed in an energy-saving resistance furnace and calcined at 550℃ for 3h to obtain a light yellow CeO 2 powder.

[0040] (3)MOFs@CeO 2 Synthesis: MOFs@CeO was prepared by ball milling 2 , 345 mg MOFs and 516 mg CeO 2 The mixture was mixed evenly, placed in a ball mill under air atmosphere, and ball milled at 100 rpm for 6 h. After the ball milling, the mixture and the small balls were sieved to obtain MOFs@CeO 2 powder.

[0041] (4)MOFs@CeO 2 Preparation of MOFs@CeO / MB / polypropylene composite fibers by melt spinning 2 / MB / polypropylene flame retardant and antibacterial composite fibers. 4wt% MOFs@CeO 2 , 4wt% MB and 92wt% polypropylene chips are melt mixed in a twin-screw extruder and extruded into a spinning box, and then delivered to a spinning assembly by a metering pump. After oiling by an oiling system and drawing and winding by a winding device, a flame-retardant and antibacterial composite fiber is obtained. In this step, the screw speed is 30Hz, the average temperature of the screw heating zone is 222℃, the spinning box temperature is 228℃, and the side blowing air volume is 24m 3 / min, the oiling rate is 3wt%, and the winding machine speed is 3200rpm.

[0042] Example 3

[0043] (1) MOFs synthesis: 5.82 g of nickel nitrate hexahydrate was added to 60 mL of deionized water and stirred for 15 min, which was recorded as solution A. 3.28 g of 2-methylimidazole and 0.2 g of NaOH were added to 60 mL of deionized water and stirred for 15 min, which was recorded as solution B. Solution B was added to solution A under magnetic stirring. Then, the solution was stirred at 40 °C for 30 min and then allowed to stand for 12 h. The precipitate was collected and dried at 80 °C for 4 h.

[0044] (2) CeO 2 Synthesis: Weigh 8.68g of cerium nitrate hexahydrate and 12.8g of sodium hydroxide, ultrasonically disperse the two in 160mL of deionized water, and then magnetically stir at room temperature for 3h to obtain a purple suspension. The suspension was centrifuged at 3000rpm for 10min to collect the precipitate, and then washed with ethanol and deionized water three times respectively. The precipitate was then dried in an oven at 60℃ for 12h, and finally the dried product was ground into powder and placed in an energy-saving resistance furnace and calcined at 550℃ for 3h to obtain a light yellow CeO 2 powder.

[0045] (3)MOFs@CeO 2 Synthesis: MOFs@CeO was prepared by ball milling 2 460 mg MOFs and 688 mg CeO 2 The mixture was mixed evenly, placed in a ball mill under air atmosphere, and ball milled at 100 rpm for 6 h. After the ball milling, the mixture and the small balls were sieved to obtain MOFs@CeO 2 powder.

[0046] (4)MOFs@CeO 2 Preparation of MOFs@CeO / MB / polypropylene composite fibers by melt spinning 2 / MB / polypropylene flame retardant and antibacterial composite fibers. 6wt% MOFs@CeO 2 , 2wt% MB and 92wt% polypropylene chips are melt mixed in a twin-screw extruder and extruded into a spinning box, and then delivered to a spinning assembly by a metering pump. After oiling by an oiling system and drawing and winding by a winding device, a flame-retardant and antibacterial composite fiber is obtained. In this step, the screw speed is 30Hz, the average temperature of the screw heating zone is 221℃, the spinning box temperature is 226℃, and the side blowing air volume is 23m 3 / min, the oiling rate is 3wt%, and the winding machine speed is 3200rpm.

[0047] Example 4

[0048] (1) MOFs synthesis: 2.71 g zinc nitrate hexahydrate was added to 30 mL deionized water and stirred for 10 min, which was recorded as solution A. 1.64 g 2-methylimidazole and 0.1 g NaOH were added to 30 mL deionized water and stirred for 10 min, which was recorded as solution B. Solution B was added to solution A under magnetic stirring. Then, the solution was stirred at 20°C for 60 min and then allowed to stand for 24 h. The precipitate was collected and dried at 60°C for 24 h.

[0049] (2) CeO 2 Synthesis: Weigh 4.34g of cerium nitrate hexahydrate and 6.4g of sodium hydroxide, ultrasonically disperse the two in 80mL of deionized water, and then magnetically stir at room temperature for 3h to obtain a purple suspension. The suspension was centrifuged at 2000rpm for 20min to collect the precipitate, and then washed with ethanol and deionized water for 4 times respectively. The precipitate was then dried in an oven at 100℃ for 13h, and finally the dried product was ground into powder and placed in an energy-saving resistance furnace and calcined at 500℃ for 6h to obtain light yellow CeO 2 powder.

[0050] (3)MOFs@CeO 2 Synthesis: MOFs@CeO was prepared by ball milling 2 , 230 mg MOFs and 344 mg CeO 2 The mixture was mixed evenly, placed in a ball mill under air atmosphere, and ball milled at 150 rpm for 7 h. After the ball milling, the mixture and the balls were sieved to obtain MOFs@CeO 2 powder.

[0051] (4)MOFs@CeO 2 Preparation of MOFs@CeO / MB / polypropylene composite fibers by melt spinning 2 / MB / polypropylene flame retardant and antibacterial composite fibers. 2wt% MOFs@CeO 2 , 6wt% MB and 92wt% polypropylene chips are melt mixed in a twin-screw extruder and extruded into a spinning box, and then delivered to a spinning assembly by a metering pump. After oiling by an oiling system and drawing and winding by a winding device, a flame-retardant and antibacterial composite fiber is obtained. In this step, the screw speed is 20Hz, the average temperature of the screw heating zone is 200℃, the spinning box temperature is 220℃, and the side blowing air volume is 15m 3 / min, the oiling rate is 2wt%, and the winding machine speed is 2000rpm.

[0052] Example 5

[0053] (1) MOFs synthesis: 2.71 g zinc nitrate hexahydrate was added to 30 mL deionized water and stirred for 10 min, which was recorded as solution A; 1.64 g 2-methylimidazole and 0.1 g NaOH were added to 30 mL deionized water and stirred for 10 min, which was recorded as solution B. Solution B was added to solution A under magnetic stirring. Then, the solution was stirred at 80 °C for 35 min and then allowed to stand for 20 h. The precipitate was collected and dried at 100 °C for 5 h.

[0054] (2) CeO 2 Synthesis: Weigh 4.34g of cerium nitrate hexahydrate and 6.4g of sodium hydroxide, ultrasonically disperse the two in 80mL of deionized water, and then magnetically stir at room temperature for 6h to obtain a purple suspension. The suspension was centrifuged at 8000rpm for 11min to collect the precipitate, and then washed with ethanol and deionized water for 5 times respectively. The precipitate was then dried in an oven at 80℃ for 20h, and finally the dried product was ground into powder and placed in an energy-saving resistance furnace for calcination at 800℃ for 4h to obtain light yellow CeO 2 powder.

[0055] (3)MOFs@CeO 2 Synthesis: MOFs@CeO was prepared by ball milling 2 , 230 mg MOFs and 344 mg CeO 2 The mixture was mixed evenly, placed in a ball mill under air atmosphere, and ball milled at 200 rpm for 8 h. After the ball milling, the mixture and the small balls were sieved to obtain MOFs@CeO 2 powder.

[0056] (4)MOFs@CeO 2 Preparation of MOFs@CeO / MB / polypropylene composite fibers by melt spinning 2 / MB / polypropylene flame retardant and antibacterial composite fibers. 2wt% MOFs@CeO 2 , 6wt% MB and 92wt% polypropylene chips are melt mixed in a twin-screw extruder and then extruded into a spinning box, and then delivered to a spinning assembly by a metering pump. After oiling by an oiling system and drawing and winding by a winding device, a flame-retardant and antibacterial composite fiber is obtained. In this step, the screw speed is 40Hz, the average temperature of the screw heating zone is 230℃, the spinning box temperature is 230℃, and the side blowing air volume is 40m 3 / min, the oiling rate is 6wt%, and the winding machine speed is 4000rpm.

[0057] According to the national standards GB / T2046.2-2009 and GB / T2048-2021, the antibacterial flame-retardant polypropylene composite fibers prepared in Examples 1-3 were prepared into specimens and flame retardant performance was tested. The vertical burning test process is as follows: Figure 1-3It was found that: in Examples 1-3, 2 wt% MOFs@CeO was added to polypropylene. 2 and 6wt%MB, 4wt%MOFs@CeO 2 and 4wt%MB, 6wt%MOFs@CeO 2 and 2wt% MB, the limiting oxygen index (LOI) of the antibacterial flame-retardant polypropylene composite fibers prepared in Examples 1-3 increased from 18.0% of polypropylene to 28.9%, 31.5%, and 30.6%, respectively, and the vertical burning test (UL94) reached V-2, V-0, and V-0 levels, respectively; Figure 4 The antibacterial test plate colony images of Examples 1 to 3 are shown. 2 When the addition amount is 2wt%, the antibacterial rate of Escherichia coli, Staphylococcus aureus and Candida albicans can reach more than 98.6%. 2 When the addition amount is greater than 4wt%, the antibacterial rates against Escherichia coli, Staphylococcus aureus and Candida albicans can reach more than 99.9%, and the antibacterial rate is still more than 98% after washing 100 times.

[0058] The flame retardant mechanism of the antibacterial flame retardant polypropylene composite fiber of the present invention is: (1) the metal ion center in MOFs can be catalyzed into carbon to form a dense protective layer during combustion, and its unique porous structure can absorb smoke and toxic gases in the early stage of combustion; (2) MB can promote the formation of thermal stability structures such as POC, BOP and C=C in the material during combustion to improve the thermal stability and carbonization of the material, and form a dense honeycomb skeleton structure to increase the density and expansion of the carbon layer, thereby achieving the purpose of flame retardancy and smoke suppression. The antibacterial mechanism of the antibacterial flame retardant polypropylene composite fiber of the present invention is: (1) MOFs achieves continuous killing of bacteria by continuously and slowly releasing intrinsic metal ions; (2) CeO 2 Under light conditions, it is excited to produce e - , H 2 O 2 、h + , ·O 2- The invention has the advantages of simple synthesis steps, mass production, good flame retardant and antibacterial effects, and can be used to prepare MOFs@CeO nanoparticles by adding only 4wt% MOFs@CeO nanoparticles. 2 And 4wt% MB can achieve high flame retardant and antibacterial effects.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should be included in the scope of the claims of the present invention. The techniques, shapes, and structural parts not described in detail in the present invention are all known technologies.

Claims

1. An antibacterial flame-retardant polypropylene composite fiber, It is characterized in that Including the following ingredients: Polypropylene 90-92wt%, MOFs@CeO 2 2.0-6.0wt%, melamine borate 2-6wt%; The method for preparing antibacterial flame-retardant polypropylene composite fiber comprises the following steps: Preparation of MOFs@CeO 2 , metal organic framework materials and CeO 2 The mixture was stirred evenly, placed in a ball mill, and ball milled at 100-200 rpm for 6-8 h, and MOFs@CeO was obtained by sieving. 2 powder; Melt spinning, take 90-92wt% polypropylene, MOFs@CeO 2 2.0-6.0wt%, melamine borate 2-6wt%, placed in a twin-screw extruder with a screw speed of 20-40Hz and a screw heating temperature of 200-230°C for melt mixing, extruded at a temperature of 220-230°C and a side blowing air volume of 15-40m 3 The fiber is spun in a spinning box at a speed of 2000 to 4000 rpm, and the antibacterial and flame-retardant polypropylene composite fiber is obtained after oiling by an oiling system and drawing and winding by a winder. The oiling rate is 2 to 6 wt % and the speed of the winder is 2000 to 4000 rpm.

2. The antibacterial flame-retardant polypropylene composite fiber according to claim 1, It is characterized in that The antibacterial flame-retardant polypropylene composite fiber comprises the following raw materials: Polypropylene 92wt%, MOFs@CeO 2 4.0 wt%, melamine borate 4wt%.

3. The antibacterial flame-retardant polypropylene composite fiber according to claim 1 or 2, It is characterized in that The MOFs@CeO 2 Metal-organic framework materials and CeO 2 The metal organic framework material and CeO 2 The molar ratio is 1:

2.

4. The antibacterial flame-retardant polypropylene composite fiber according to claim 3, It is characterized in that The preparation method of the metal organic framework material is as follows: Add soluble nitrate into deionized water and stir for 10 to 15 minutes, which is recorded as solution A; add 2-methylimidazole and NaOH into deionized water and stir for 10 to 15 minutes, which is recorded as solution B; add solution B into solution A under stirring, then stir magnetically at 20 to 80° C. for 30 to 60 minutes and then stand for 12 to 24 hours, collect the precipitate and dry it at 60 to 100° C. for 4 to 24 hours to obtain a metal organic framework material.

5. The antibacterial flame-retardant polypropylene composite fiber according to claim 4, It is characterized in that The molar volume ratio of the soluble nitrate, 2-methylimidazole, NaOH and deionized water is 10mmol:20mmol:2.5mmol:60mL.

6. The antibacterial flame-retardant polypropylene composite fiber according to claim 5, It is characterized in that The soluble nitrate is one of zinc nitrate hexahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate, and iron nitrate nonahydrate.

7. The antibacterial flame-retardant polypropylene composite fiber according to claim 6, It is characterized in that The CeO 2 The preparation method is as follows: The cerium nitrate hexahydrate and sodium hydroxide are weighed and mixed, and ultrasonically dispersed in deionized water and stirred at room temperature for 3 to 6 hours to obtain a suspension; the suspension is centrifuged at a speed of 2000 to 8000 rpm for 10 to 20 minutes, and the precipitate is collected and washed with ethanol and deionized water for 3 to 5 times respectively, and then the precipitate is dried in an oven at 60 to 100° C. for 12 to 24 hours, ground into powder, and calcined at 500 to 800° C. for 3 to 6 hours to obtain CeO 2 powder.

8. The antibacterial flame-retardant polypropylene composite fiber according to claim 7, It is characterized in that The molar volume ratio of the cerium nitrate hexahydrate, sodium hydroxide and deionized water is 10 mmol:160 mmol:80 mL.

Images