Styrene-butadiene rubber toughened polypropylene antibacterial composite material and preparation method thereof

Abstract

The invention relates to the technical field of polypropylene, and discloses a styrene-butadiene rubber toughened polypropylene antibacterial composite material, nano titanium dioxide can generate stress concentration and initiate micro-cracking of matrix resin, so that deformation work is absorbed, crack propagation is blocked and passivated, styrene-butadiene rubber is added into a polypropylene matrix, and in a proper range, the antibacterial performance of the polypropylene is improved. The surface of the quaternary phosphonium salt is positively charged, the quaternary phosphonium salt can be adsorbed on the surface of bacteria with negative electricity through coulomb acting force, and an alkyl chain can be mutually combined with a phospholipid bilayer on a cell membrane through hydrophobic interaction, so that bacterial death is caused; the nano titanium dioxide generates superoxide free radicals O2. And hydroxyl free radicals OH. To oxidize and decompose organic matters in bacteria to death the bacteria, and the composite material obtained by mixing the nano titanium dioxide with the polypropylene matrix has excellent antibacterial performance and toughness.

Description

Technical Field

[0001] The invention relates to the technical field of polypropylene, in particular to a styrene-butadiene rubber toughened polypropylene antibacterial composite material and a preparation method thereof. Background Art

[0002] As one of the five general-purpose plastics, polypropylene is easy to process and shape. It is a colorless, non-toxic thermoplastic synthetic resin that is light and inexpensive. It has the characteristics of chemical corrosion resistance, heat resistance and wear resistance. It is widely used in machinery, construction, packaging, food industry and other fields. Due to its excellent plasticity, it is gradually replacing some wood and metal materials. However, polypropylene has the defects of poor impact resistance and general aging resistance. At the same time, plastic products do not have antibacterial properties, which limits its application in some fields.

[0003] By adding toughening agents to the polypropylene matrix, its mechanical properties can be effectively improved. As a rubber product with excellent physical properties, styrene-butadiene rubber has excellent mechanical properties and aging resistance, and can effectively change the mechanical properties of the matrix. By adding rigid inorganic nanoparticles, such as graphene, carbon nanotubes and nano-titanium dioxide, the mechanical properties of the matrix can also be improved. Among them, nano-titanium dioxide is also an inorganic antibacterial agent with excellent antibacterial properties. Adding organic small molecule antibacterial agents such as quaternary ammonium salts, quaternary phosphonium salts, guanidines, etc. can effectively improve the antibacterial properties of the matrix. The antibacterial agent and toughening agent are added to the polypropylene matrix, and the mixed polypropylene matrix has excellent antibacterial and mechanical properties. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a styrene-butadiene rubber toughened polypropylene antibacterial composite material and a preparation method thereof, which solves the problems of poor antibacterial performance and poor toughness of polypropylene.

[0005] To achieve the above object, the present invention provides the following technical solution: a styrene-butadiene rubber toughened polypropylene antibacterial composite material, the styrene-butadiene rubber toughened polypropylene antibacterial composite material and the preparation method are as follows: (1) A tetrahydrofuran solvent, carboxyl-terminated styrene butadiene rubber, pyridine and thionyl chloride are stirred and mixed, heated under reflux to react, and after the reaction is completed, acyl chloride styrene butadiene rubber is obtained; (2) 8000-15000 parts by weight of ethanol solvent, 100 parts by weight of nano-titanium dioxide and 150-250 parts by weight of γ-aminopropyltriethoxysilane are uniformly dispersed by ultrasonication, and reacted at 55-75° C. for 5-10 hours. After the reaction is completed, amino titanium dioxide is obtained; (3) stirring and mixing tetrahydrofuran solvent, acyl chloride styrene butadiene rubber, amino titanium dioxide and triethylamine to react, and after the reaction is completed, titanium dioxide grafted acyl chloride styrene butadiene rubber is obtained; (4) stirring the dichloromethane solvent, titanium dioxide grafted acyl chloride styrene butadiene rubber, 11-bromo-1-undecanol and triethylamine at 0-5°C, heating, and reacting at 20-40°C for 24-36 hours. After the reaction is completed, titanium dioxide grafted brominated alkyl styrene butadiene rubber is obtained; (5) stirring the dimethyl sulfoxide solvent, titanium dioxide grafted alkyl brominated styrene butadiene rubber, triphenylphosphine and the polymerization inhibitor hydroquinone evenly to react, and after the reaction is completed, obtaining a quaternary phosphonium salt modified titanium dioxide based styrene butadiene rubber; (6) Add polypropylene, quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber and dispersant polyethylene wax into a high-speed mixer, mix them evenly, add them into a twin-screw extruder, melt granulate them at 180-210° C., and extrude them at a screw speed of 300-400 r / min to obtain a styrene-butadiene rubber-toughened polypropylene antibacterial composite material.

[0006] Preferably, in step (1), the mass fractions of tetrahydrofuran are 1500-5000 parts, the mass fractions of carboxyl-terminated styrene-butadiene rubber are 100 parts, the mass fractions of pyridine are 0.4-1.5 parts, and the mass fractions of thionyl chloride are 20-80 parts.

[0007] Preferably, the reaction temperature in step (1) is 60-85° C., and the reaction time is 8-16 h.

[0008] Preferably, in step (3), the mass fractions of tetrahydrofuran are 2000-4000 parts, the mass fractions of acyl chloride styrene butadiene rubber are 100 parts, the mass fractions of amination titanium dioxide are 20-40 parts, and the mass fractions of triethylamine are 120-150 parts.

[0009] Preferably, the reaction temperature in step (3) is 5-15° C., and the reaction time is 4-8 h.

[0010] Preferably, in step (4), the weight proportions of dichloromethane are 2000-5000 parts, the weight proportions of titanium dioxide grafted acyl chloride-based styrene-butadiene rubber are 100 parts, the weight proportions of 11-bromo-1-undecanol are 220-260 parts, and the weight proportions of triethylamine are 90-120 parts.

[0011] Preferably, in step (5), the mass fractions of dimethyl sulfoxide are 2500-5000 parts, the mass fractions of titanium dioxide grafted bromoalkyl styrene butadiene rubber are 100 parts, the mass fractions of triphenylphosphine are 120-300 parts, and the mass fractions of hydroquinone are 2-5 parts.

[0012] Preferably, the reaction temperature in step (5) is 60-80° C., and the reaction time is 8-15 h.

[0013] Preferably, in step (6), the mass fractions of polypropylene are 100 parts, the mass fractions of quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber are 2-6 parts, and the mass fractions of polyethylene wax are 0.5-2 parts.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: The invention discloses a styrene-butadiene rubber toughened polypropylene antibacterial composite material. In tetrahydrofuran solvent, under the action of catalyst pyridine, thionyl chloride is used to modify terminal carboxyl styrene-butadiene rubber to obtain acyl chloride styrene-butadiene rubber, an acyl chloride group at one end of the acyl chloride styrene-butadiene rubber and an amino group on aminated titanium dioxide undergo amidation reaction to obtain titanium dioxide grafted acyl chloride styrene-butadiene rubber, nano titanium dioxide is grafted onto the styrene-butadiene rubber to effectively avoid agglomeration of inorganic particles, a hydroxyl group on 11-bromo-1-undecanol and a chlorine on the titanium dioxide grafted acyl chloride styrene-butadiene rubber undergo substitution reaction to obtain titanium dioxide grafted brominated alkyl styrene-butadiene rubber, a bromine atom reacts with triphenylphosphine to produce a quaternary phosphonium salt to obtain a quaternary phosphonium salt modified titanium dioxide-based styrene-butadiene rubber, polypropylene and the quaternary phosphonium salt modified titanium dioxide-based styrene-butadiene rubber are mixed by melt blending to obtain the styrene-butadiene rubber toughened polypropylene antibacterial composite material.

[0015] The invention discloses a styrene-butadiene rubber toughened polypropylene antibacterial composite material. Nano titanium dioxide can generate stress concentration, induce micro cracking of matrix resin, thereby absorbing deformation work, hindering and passivating crack expansion. The styrene-butadiene rubber particles are small and are added to the polypropylene matrix. With the addition of the styrene-butadiene rubber, within a proper range, the distance between the particles becomes shorter, the probability of silver streaks and colloid particles meeting increases, the silver streaks are easily terminated or turned into short silver streaks, which is conducive to the occurrence of silver streaks, thereby achieving a toughening effect. The surface of the quaternary phosphonium salt is positively charged and can be adsorbed on the surface of negatively charged bacteria through Coulomb force. At the same time, since the phosphorus atom has a large original The sub-radius has a stronger positive charge and has a strong adsorption effect on bacteria. The alkyl chains contained in it can combine with the phospholipid bilayer on the cell membrane through hydrophobic interaction, resulting in cell membrane lysis, the outflow of proteins, DNA and other substances in the bacterial cells, and the death of bacteria. The valence band of nano-titanium dioxide is full of electrons, and the conduction band is an empty energy level orbit without electrons. When exposed to light, the electrons in the valence band jump to the conduction band of a higher energy level after absorbing light energy and become high-energy electrons. The valence band becomes a positively charged hole. The high-energy electrons and holes react with oxygen and water to produce superoxide free radicals O 2 · and hydroxyl free radicals OH·. Free radicals have strong oxidizing properties and can oxidize and decompose organic matter in bacteria, causing the bacteria to die. Inorganic antibacterial agents titanium dioxide and quaternary phosphonium salts have better antibacterial effects through compounding. The composite material obtained by mixing with the polypropylene matrix has excellent antibacterial properties and toughness. DETAILED DESCRIPTION

[0016] To achieve the above object, the present invention provides the following specific implementation methods and examples: A method for preparing a styrene-butadiene rubber toughened polypropylene antibacterial composite material is as follows: (1) Adding 1500-5000 parts by weight of tetrahydrofuran solvent, 100 parts by weight of carboxyl-terminated styrene butadiene rubber, 0.4-1.5 parts by weight of pyridine and 20-80 parts by weight of thionyl chloride to a reaction container, stirring, heating under reflux, reacting at 60-85° C. for 8-16 hours, and after the reaction is completed, rotary evaporation and drying to obtain chlorinated styrene butadiene rubber; (2) adding 8000-15000 parts by weight of ethanol solvent, 100 parts by weight of nano-titanium dioxide and 150-250 parts by weight of γ-aminopropyltriethoxysilane to a reaction container, uniformly dispersing by ultrasonication, reacting at 55-75° C. for 5-10 hours, and after the reaction, washing with ethanol and deionized water, centrifuging and drying to obtain amino titanium dioxide; (3) Adding 2000-4000 parts by weight of tetrahydrofuran solvent, 100 parts by weight of acyl chloride styrene butadiene rubber, 20-40 parts by weight of amino titanium dioxide and 120-150 parts by weight of triethylamine to a reaction container, stirring, reacting at 5-15° C. for 4-8 hours. After the reaction is completed, filtering, washing with deionized water, and drying to obtain titanium dioxide grafted acyl chloride styrene butadiene rubber; (4) adding 2000-5000 parts by weight of dichloromethane solvent, 100 parts by weight of titanium dioxide grafted acyl chloride-based styrene-butadiene rubber, 220-260 parts by weight of 11-bromo-1-undecanol and 90-120 parts by weight of triethylamine to the reactor, stirring evenly at 0-5° C., heating, reacting at 20-40° C. for 24-36 hours, and after the reaction is completed, rotary evaporation to obtain titanium dioxide grafted brominated alkyl styrene-butadiene rubber; (5) Add 2500-5000 parts by weight of dimethyl sulfoxide solvent, 100 parts by weight of titanium dioxide grafted bromoalkyl styrene butadiene rubber, 120-300 parts by weight of triphenylphosphine and 2-5 parts by weight of inhibitor hydroquinone to the reactor, stir evenly, react at 60-80° C. for 8-15 hours. After the reaction is completed, cool, wash with deionized water and acetone, and dry to obtain quaternary phosphonium salt modified titanium dioxide-based styrene butadiene rubber; (6) Add 100 parts by weight of polypropylene, 2-6 parts by weight of quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber and 0.5-2 parts by weight of dispersant polyethylene wax into a high-speed mixer in sequence, mix well, add to a twin-screw extruder, melt granulate at 180-210°C, and extrude at a screw speed of 300-400 r / min to obtain a styrene-butadiene rubber toughened polypropylene antibacterial composite material. Example 1

[0017] (1) Adding 1500 parts by weight of tetrahydrofuran solvent, 100 parts by weight of carboxyl-terminated styrene butadiene rubber, 0.4 parts by weight of pyridine and 20 parts by weight of thionyl chloride into a reaction container, stirring, heating under reflux, reacting at 60° C. for 8 hours, and after the reaction is completed, rotary evaporation and drying to obtain chlorinated styrene butadiene rubber; (2) adding 8000 parts by weight of ethanol solvent, 100 parts by weight of nano-titanium dioxide and 150 parts by weight of γ-aminopropyltriethoxysilane to a reaction container, uniformly dispersing by ultrasonication, reacting at 55° C. for 5 h, and after the reaction, washing with ethanol and deionized water, centrifuging and drying to obtain amino titanium dioxide; (3) Add 2000 parts by weight of tetrahydrofuran solvent, 100 parts by weight of acyl chloride styrene butadiene rubber, 20 parts by weight of amino titanium dioxide and 120 parts by weight of triethylamine to a reaction container, stir, react at 5° C. for 4 hours, and after the reaction is completed, filter, wash with deionized water, and dry to obtain titanium dioxide grafted acyl chloride styrene butadiene rubber; (4) Add 2000 parts by weight of dichloromethane solvent, 100 parts by weight of titanium dioxide grafted acyl chloride-based styrene butadiene rubber, 220 parts by weight of 11-bromo-1-undecanol and 90 parts by weight of triethylamine to the reactor, stir evenly at 0° C., heat, and react at 20° C. for 24 hours. After the reaction is completed, perform rotary evaporation to obtain titanium dioxide grafted brominated alkyl styrene butadiene rubber; (5) Add 2500 parts by weight of dimethyl sulfoxide solvent, 100 parts by weight of titanium dioxide grafted alkyl brominated styrene butadiene rubber, 120 parts by weight of triphenylphosphine and 2 parts by weight of inhibitor hydroquinone into the reactor, stir evenly, react at 60° C. for 8 hours. After the reaction is completed, cool, wash with deionized water and acetone, and dry to obtain quaternary phosphonium salt modified titanium dioxide-based styrene butadiene rubber; (6) Add 100 parts by weight of polypropylene, 2 parts by weight of quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber and 0.5 parts by weight of dispersant polyethylene wax into a high-speed mixer in sequence, mix well, add the mixture into a twin-screw extruder, melt granulate at 180°C, and extrude at a screw speed of 300 r / min to obtain a styrene-butadiene rubber-toughened polypropylene antibacterial composite material. Example 2

[0018] (1) Adding 2500 parts by weight of tetrahydrofuran solvent, 100 parts by weight of carboxyl-terminated styrene butadiene rubber, 0.6 parts by weight of pyridine and 30 parts by weight of thionyl chloride into a reaction container, stirring, heating under reflux, reacting at 65° C. for 10 hours, and after the reaction is completed, rotary evaporation and drying to obtain chlorinated styrene butadiene rubber; (2) adding 10,000 parts by weight of ethanol solvent, 100 parts by weight of nano-titanium dioxide and 180 parts by weight of γ-aminopropyltriethoxysilane to a reaction container, uniformly dispersing by ultrasonication, reacting at 60° C. for 6 h, and after the reaction, washing with ethanol and deionized water, centrifuging and drying to obtain amino titanium dioxide; (3) Add 2500 parts by weight of tetrahydrofuran solvent, 100 parts by weight of acyl chloride styrene butadiene rubber, 25 parts by weight of amino titanium dioxide and 128 parts by weight of triethylamine to a reaction container, stir, react at 8° C. for 5 hours, and after the reaction is completed, filter, wash with deionized water, and dry to obtain titanium dioxide grafted acyl chloride styrene butadiene rubber; (4) Add 2800 parts by weight of dichloromethane solvent, 100 parts by weight of titanium dioxide grafted acyl chloride-based styrene butadiene rubber, 230 parts by weight of 11-bromo-1-undecanol and 100 parts by weight of triethylamine to the reactor, stir evenly at 2° C., heat, and react at 25° C. for 30 hours. After the reaction is completed, perform rotary evaporation to obtain titanium dioxide grafted brominated alkyl styrene butadiene rubber; (5) 3200 parts by weight of dimethyl sulfoxide solvent, 100 parts by weight of titanium dioxide grafted bromoalkyl styrene butadiene rubber, 150 parts by weight of triphenylphosphine and 2.8 parts by weight of inhibitor hydroquinone were added to the reactor in sequence, stirred evenly, reacted at 65° C. for 9 hours. After the reaction was completed, cooled, washed with deionized water and acetone, and dried to obtain quaternary phosphonium salt modified titanium dioxide-based styrene butadiene rubber; (6) 100 parts by weight of polypropylene, 3 parts by weight of quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber and 0.8 parts by weight of dispersant polyethylene wax were added to a high-speed mixer in sequence. After mixing evenly, the mixture was added to a twin-screw extruder and melt-granulated at 185°C. The screw speed was 320 r / min, and the mixture was extruded to obtain a styrene-butadiene rubber-toughened polypropylene antibacterial composite material. Example 3

[0019] (1) Adding 3500 parts by weight of tetrahydrofuran solvent, 100 parts by weight of carboxyl-terminated styrene butadiene rubber, 0.8 parts by weight of pyridine and 40 parts by weight of thionyl chloride into a reaction container, stirring, heating under reflux, reacting at 70° C. for 12 hours, and after the reaction is completed, rotary evaporation and drying to obtain chlorinated styrene butadiene rubber; (2) adding 12,000 parts by weight of ethanol solvent, 100 parts by weight of nano-titanium dioxide and 200 parts by weight of γ-aminopropyltriethoxysilane to a reaction container, uniformly dispersing by ultrasonication, reacting at 65° C. for 7 h, and after the reaction, washing with ethanol and deionized water, centrifuging and drying to obtain amino titanium dioxide; (3) Add 3000 parts by weight of tetrahydrofuran solvent, 100 parts by weight of acyl chloride styrene butadiene rubber, 30 parts by weight of amino titanium dioxide and 135 parts by weight of triethylamine to a reaction container, stir, react at 10° C. for 6 hours, and after the reaction is completed, filter, wash with deionized water, and dry to obtain titanium dioxide grafted acyl chloride styrene butadiene rubber; (4) 4000 parts by weight of dichloromethane solvent, 100 parts by weight of titanium dioxide grafted acyl chloride-based styrene butadiene rubber, 245 parts by weight of 11-bromo-1-undecanol and 105 parts by weight of triethylamine were added to the reactor in sequence, stirred evenly at 2° C., heated, and reacted at 30° C. for 32 hours. After the reaction was completed, rotary evaporation was performed to obtain titanium dioxide grafted brominated alkyl styrene butadiene rubber; (5) 4000 parts by weight of dimethyl sulfoxide solvent, 100 parts by weight of titanium dioxide grafted bromoalkyl styrene butadiene rubber, 200 parts by weight of triphenylphosphine and 3.5 parts by weight of inhibitor hydroquinone were added to the reactor in sequence, stirred evenly, reacted at 70° C. for 12 hours. After the reaction was completed, cooled, washed with deionized water and acetone, and dried to obtain quaternary phosphonium salt modified titanium dioxide-based styrene butadiene rubber; (6) Add 100 parts by weight of polypropylene, 4 parts by weight of quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber and 1.2 parts by weight of dispersant polyethylene wax into a high-speed mixer in sequence, mix well, add to a twin-screw extruder, melt granulate at 195°C, and extrude at a screw speed of 350 r / min to obtain a styrene-butadiene rubber toughened polypropylene antibacterial composite material. Example 4

[0020] (1) Adding 4200 parts by weight of tetrahydrofuran solvent, 100 parts by weight of carboxyl-terminated styrene butadiene rubber, 1.2 parts by weight of pyridine and 70 parts by weight of thionyl chloride into a reaction container, stirring, heating under reflux, reacting at 80° C. for 15 hours, and after the reaction is completed, rotary evaporation and drying to obtain chlorinated styrene butadiene rubber; (2) adding 14,000 parts by weight of ethanol solvent, 100 parts by weight of nano-titanium dioxide and 220 parts by weight of γ-aminopropyltriethoxysilane to a reaction container, uniformly dispersing by ultrasonication, reacting at 70° C. for 9 hours, and after the reaction, washing with ethanol and deionized water, centrifuging and drying to obtain amino titanium dioxide; (3) Add 3500 parts by weight of tetrahydrofuran solvent, 100 parts by weight of acyl chloride styrene butadiene rubber, 35 parts by weight of amino titanium dioxide and 142 parts by weight of triethylamine to a reaction container, stir, react at 12° C. for 7 hours, and after the reaction is completed, filter, wash with deionized water, and dry to obtain titanium dioxide grafted acyl chloride styrene butadiene rubber; (4) 4500 parts by weight of dichloromethane solvent, 100 parts by weight of titanium dioxide grafted acyl chloride-based styrene butadiene rubber, 255 parts by weight of 11-bromo-1-undecanol and 110 parts by weight of triethylamine were added to the reactor in sequence, stirred evenly at 4° C., heated, and reacted at 35° C. for 34 hours. After the reaction was completed, rotary evaporation was performed to obtain titanium dioxide grafted brominated alkyl styrene butadiene rubber; (5) 4500 parts by weight of dimethyl sulfoxide solvent, 100 parts by weight of titanium dioxide grafted alkyl brominated styrene butadiene rubber, 250 parts by weight of triphenylphosphine and 4.2 parts by weight of inhibitor hydroquinone were added to the reactor in sequence, stirred evenly, reacted at 75° C. for 14 hours. After the reaction was completed, cooled, washed with deionized water and acetone, and dried to obtain quaternary phosphonium salt modified titanium dioxide-based styrene butadiene rubber; (6) Add 100 parts by weight of polypropylene, 5 parts by weight of quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber and 1.6 parts by weight of dispersant polyethylene wax into a high-speed mixer in sequence, mix well, add to a twin-screw extruder, melt granulate at 200°C, and extrude at a screw speed of 380 r / min to obtain a styrene-butadiene rubber toughened polypropylene antibacterial composite material. Example 5

[0021] (1) Adding 5000 parts by weight of tetrahydrofuran solvent, 100 parts by weight of carboxyl-terminated styrene butadiene rubber, 1.5 parts by weight of pyridine and 80 parts by weight of thionyl chloride into a reaction container, stirring, heating under reflux, reacting at 85° C. for 16 hours, and after the reaction is completed, rotary evaporation and drying to obtain chlorinated styrene butadiene rubber; (2) adding 15,000 parts by weight of ethanol solvent, 100 parts by weight of nano-titanium dioxide and 250 parts by weight of γ-aminopropyltriethoxysilane to a reaction container, dispersing them uniformly by ultrasonication, reacting at 75° C. for 10 hours, and after the reaction, washing with ethanol and deionized water, centrifuging and drying to obtain amino titanium dioxide; (3) Add 4000 parts by weight of tetrahydrofuran solvent, 100 parts by weight of acyl chloride styrene butadiene rubber, 40 parts by weight of amino titanium dioxide and 150 parts by weight of triethylamine to a reaction container, stir, react at 15° C. for 8 hours, and after the reaction is completed, filter, wash with deionized water, and dry to obtain titanium dioxide grafted acyl chloride styrene butadiene rubber; (4) 5000 parts by weight of dichloromethane solvent, 100 parts by weight of titanium dioxide grafted acyl chloride-based styrene butadiene rubber, 260 parts by weight of 11-bromo-1-undecanol and 120 parts by weight of triethylamine were added to the reactor in sequence, stirred evenly at 5° C., heated, and reacted at 40° C. for 36 hours. After the reaction was completed, rotary evaporation was performed to obtain titanium dioxide grafted brominated alkyl styrene butadiene rubber; (5) Add 5000 parts by weight of dimethyl sulfoxide solvent, 100 parts by weight of titanium dioxide grafted bromoalkyl styrene butadiene rubber, 300 parts by weight of triphenylphosphine and 5 parts by weight of inhibitor hydroquinone to the reactor, stir evenly, react at 80° C. for 15 hours. After the reaction is completed, cool, wash with deionized water and acetone, and dry to obtain quaternary phosphonium salt modified titanium dioxide-based styrene butadiene rubber; (6) Add 100 parts by weight of polypropylene, 6 parts by weight of quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber and 2 parts by weight of dispersant polyethylene wax into a high-speed mixer in sequence, mix well, add the mixture into a twin-screw extruder, melt granulate at 210°C, and extrude at a screw speed of 400 r / min to obtain a styrene-butadiene rubber-toughened polypropylene antibacterial composite material.

[0022] Comparative Example 1 (1) Adding 3000 parts by weight of tetrahydrofuran solvent, 100 parts by weight of carboxyl-terminated styrene butadiene rubber, 1 part by weight of pyridine and 50 parts by weight of thionyl chloride into a reaction container, stirring, heating under reflux, reacting at 75° C. for 12 hours, and after the reaction is completed, rotary evaporation and drying to obtain chlorinated styrene butadiene rubber; (2) 100 parts by weight of polypropylene, 4 parts by weight of acyl chloride styrene butadiene rubber and 1.2 parts by weight of dispersant polyethylene wax were added to a high-speed mixer in sequence. After being mixed evenly, the mixture was added to a twin-screw extruder and melt-granulated at 200°C. The screw speed was 350 r / min and the mixture was extruded to obtain a styrene butadiene rubber toughened polypropylene composite material.

[0023] First, Escherichia coli was inoculated into the seed culture medium to prepare liquid culture medium and plate culture medium, and cultured for 24 h under constant temperature to obtain seed solution, which was diluted to 1.5×10 6 CFU / mL, aspirate the seed liquid into the solid plate culture medium, spread the materials synthesized in the embodiment and the comparative example in the center of the plate, invert and culture at 37°C constant temperature for 24 h, then transfer to a sealed glass box, irradiate with a 60W ultraviolet lamp, and after irradiation for 6 h, observe and record the colony concentration.

[0024]

[0025] The materials synthesized in the embodiments and comparative examples were cut into samples, and the impact strength was tested using a XCJD pendulum impact tester. The corresponding data were recorded. Each group was tested three times and the average value was taken.

[0026]

Claims

1. A styrene-butadiene rubber toughened polypropylene antibacterial composite material, characterized in that: The styrene-butadiene rubber toughened polypropylene antibacterial composite material and preparation method are as follows: (1) A tetrahydrofuran solvent, carboxyl-terminated styrene butadiene rubber, pyridine and thionyl chloride are stirred and mixed, heated under reflux to react, and after the reaction is completed, acyl chloride styrene butadiene rubber is obtained; (2) 8000-15000 parts by weight of ethanol solvent, 100 parts by weight of nano-titanium dioxide and 150-250 parts by weight of γ-aminopropyltriethoxysilane are uniformly dispersed by ultrasonication, and reacted at 55-75° C. for 5-10 hours. After the reaction is completed, amino titanium dioxide is obtained; (3) stirring and mixing tetrahydrofuran solvent, acyl chloride styrene butadiene rubber, amino titanium dioxide and triethylamine to react, and after the reaction is completed, titanium dioxide grafted acyl chloride styrene butadiene rubber is obtained; (4) stirring the dichloromethane solvent, titanium dioxide grafted acyl chloride styrene butadiene rubber, 11-bromo-1-undecanol and triethylamine at 0-5°C, heating, and reacting at 20-40°C for 24-36 hours. After the reaction is completed, titanium dioxide grafted brominated alkyl styrene butadiene rubber is obtained; (5) stirring the dimethyl sulfoxide solvent, titanium dioxide grafted alkyl brominated styrene butadiene rubber, triphenylphosphine and the polymerization inhibitor hydroquinone evenly to react, and after the reaction is completed, obtaining a quaternary phosphonium salt modified titanium dioxide based styrene butadiene rubber; (6) Add polypropylene, quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber and dispersant polyethylene wax into a high-speed mixer, mix them evenly, add them into a twin-screw extruder, melt granulate them at 180-210° C., and extrude them at a screw speed of 300-400 r / min to obtain a styrene-butadiene rubber-toughened polypropylene antibacterial composite material.

2. The styrene-butadiene rubber toughened polypropylene antibacterial composite material according to claim 1, characterized in that: In the step (1), the mass fractions of tetrahydrofuran are 1500-5000 parts, the mass fractions of carboxyl-terminated styrene-butadiene rubber are 100 parts, the mass fractions of pyridine are 0.4-1.5 parts, and the mass fractions of thionyl chloride are 20-80 parts.

3. The styrene-butadiene rubber toughened polypropylene antibacterial composite material according to claim 1, characterized in that: The reaction temperature in step (1) is 60-85° C. and the reaction time is 8-16 h.

4. The styrene-butadiene rubber toughened polypropylene antibacterial composite material according to claim 1, characterized in that: In the step (3), the mass fractions of tetrahydrofuran are 2000-4000 parts, the mass fractions of acyl chloride styrene butadiene rubber are 100 parts, the mass fractions of amination titanium dioxide are 20-40 parts, and the mass fractions of triethylamine are 120-150 parts.

5. The styrene-butadiene rubber toughened polypropylene antibacterial composite material according to claim 1, characterized in that: The reaction temperature in step (3) is 5-15° C. and the reaction time is 4-8 h.

6. The styrene-butadiene rubber toughened polypropylene antibacterial composite material according to claim 1, characterized in that: In the step (4), the weight proportions of dichloromethane are 2000-5000 parts, the weight proportions of titanium dioxide grafted acyl chloride-based styrene-butadiene rubber are 100 parts, the weight proportions of 11-bromo-1-undecanol are 220-260 parts, and the weight proportions of triethylamine are 90-120 parts.

7. The styrene-butadiene rubber toughened polypropylene antibacterial composite material according to claim 1, characterized in that: In the step (5), the mass fractions of dimethyl sulfoxide are 2500-5000 parts, the mass fractions of titanium dioxide grafted brominated alkyl styrene butadiene rubber are 100 parts, the mass fractions of triphenylphosphine are 120-300 parts, and the mass fractions of hydroquinone are 2-5 parts.

8. The styrene-butadiene rubber toughened polypropylene antibacterial composite material according to claim 1, characterized in that: The reaction temperature in step (5) is 60-80°C and the reaction time is 8-15h.

9. The styrene-butadiene rubber toughened polypropylene antibacterial composite material according to claim 1, characterized in that: In the step (6), the mass fractions of polypropylene are 100 parts, the mass fractions of quaternary phosphonium salt-modified titanium dioxide-based styrene-butadiene rubber are 2-6 parts, and the mass fractions of polyethylene wax are 0.5-2 parts.

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