A high-strength antibacterial plastic packaging bottle and preparation method thereof

Abstract

The invention relates to the technical field of plastics, in particular to a high-strength antibacterial plastic packaging bottle and a preparation method thereof. The invention comprises the following steps: polylactic acid, polybutylene succinate, epoxy soybean oil and composite zinc oxide are mixed, extruded into granules and blow-molded to obtain a base member; tea polyphenols are carried on a carrier of mesoporous nano zinc oxide, which is then coated with carboxymethyl chitosan and grafted with an epoxy compound containing Si-O segments; a protective coating is prepared by using the composite zinc oxide and soybean oil-based self-healing waterborne polyurethane, and the protective coating is coated on the surface of the base member; a polyurethane prepolymer is prepared by using soybean oil-based polyol, polytetramethylene ether glycol and isophorone diisocyanate as raw materials, 2,2-bis(hydroxymethyl)propionic acid is used as a hydrophilic chain extender, the epoxy compound containing Si-O segments is used as a modifier, 1,4-butanediol and dithiodiethanol are used as end-capping agents, triethylamine is used as a neutralizing agent, and ethylenediamine and tetraethylenepentamine are used as amine cross-linking agents to prepare the soybean oil-based self-healing waterborne polyurethane.

Description

Technical Field

[0001] The invention relates to the technical field of plastics, in particular to a high-strength antibacterial plastic packaging bottle and a preparation method thereof. Background Art

[0002] With the rapid development of society, people's attention to quality of life and food safety has gradually increased, thus forming requirements for green, healthy and safe products. Antibacterial plastic packaging is a new type of packaging material that has gradually emerged in recent years. Its bactericidal and antibacterial properties can effectively improve the hygiene of the environment.

[0003] Existing common antibacterial plastic packaging is mostly made of polyethylene, polyvinyl chloride, and polypropylene as base materials with antibacterial agents added. It is difficult to degrade and pollutes the environment when discarded after large-scale use. At the same time, most plastic packaging bottles have short-lived antibacterial effects and low mechanical strength. Summary of the Invention

[0004] The object of the present invention is to provide a high-strength antibacterial plastic packaging bottle and a preparation method thereof, so as to solve the problems in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A method for preparing a high-strength antibacterial plastic packaging bottle comprises the following steps:

[0007] S1: polylactic acid, polybutylene succinate, epoxy soybean oil, and composite zinc oxide are mixed, extruded into granules, and blow-molded to obtain a base part;

[0008] S2: Preparation of protective coatings using composite zinc oxide and soybean oil-based self-healing waterborne polyurethane;

[0009] S3: coating the protective coating on the surface of the base member and curing the coating to obtain a high-strength antibacterial plastic packaging bottle.

[0010] Furthermore, the curing working conditions are: keeping warm at 90-110°C for 1-2 hours.

[0011] Furthermore, the mass ratio of polylactic acid, polybutylene succinate, epoxy soybean oil and composite zinc oxide is 79:10:4:7.

[0012] Furthermore, the mass ratio of the composite zinc oxide and the soybean oil-based self-healing waterborne polyurethane in the protective coating is 9-14%.

[0013] Furthermore, the preparation of composite zinc oxide comprises the following steps:

[0014] (1) Zinc nitrate hexahydrate, carbamide, and deionized water are mixed, polyoxyethylene polyoxypropylene ether block copolymer and sucrose are added, the pH of the solution is adjusted to 4-5, stirred for 1-2 hours, transferred to a reactor, heated to 88-92°C and kept warm for 22-24 hours, cooled, centrifuged, washed, dried, and extracted with anhydrous ethanol using a Soxhlet extractor for 12 hours, dried, and kept warm at 270°C for 1.5 hours to obtain mesoporous nano zinc oxide;

[0015] (2) Mixing tea polyphenols and deionized water, adding a mixture of mesoporous nano zinc oxide and deionized water, ultrasonically stirring for 1-3 minutes, vacuum stirring for 20-30 minutes, adding a mixture of carboxymethyl chitosan and deionized water, ultrasonically dispersing for 10-15 minutes, adding a mixture of liquid paraffin and Span-80, stirring for 20-30 minutes, adding glutaraldehyde solution, heating to 40-50°C and keeping warm for 1-2 hours, adjusting the pH value of the solution to 9-10, heating to 68-72°C and keeping warm for 2-3 hours, washing with acetone, petroleum ether, and anhydrous ethanol in sequence, and drying to obtain zinc oxide composite microspheres;

[0016] (3) Mixing the epoxy compound containing Si-O segments, zinc oxide composite microspheres, and ethanol, heating to 88-92° C., adding zinc acetate, stirring for 1-2 hours, cooling, washing, and drying to obtain composite zinc oxide.

[0017] Furthermore, the preparation of soybean oil-based self-healing waterborne polyurethane includes the following steps:

[0018] 1) Mix polyethylene glycol monomethyl ether and tetrafluoroboric acid, raise the temperature to 60-65° C. and keep warm for 30-40 minutes, add epoxidized soybean oil, continue to keep warm for 110-120 minutes, add to ethyl acetate, add saturated brine to extract, dry with anhydrous magnesium sulfate, filter, and rotary evaporate to obtain soybean oil-based polyol;

[0019] 2) Under a nitrogen atmosphere, soybean oil-based polyol, polytetramethylene ether glycol, and isophorone diisocyanate are mixed, heated to 75-80°C and kept warm for 8-12 minutes, 2,2-bis(hydroxymethyl)propionic acid, dibutyltin dilaurate, and N,N-dimethylformamide are added, and the mixture is kept warm for 1-2 hours. A mixture of Si-O segmented epoxy compound and N,N-dimethylformamide is added, and the mixture is kept warm for 1-2 hours. The mixture is cooled to 55-57°C, 1,4-butanediol, dithiodiethanol, and butanone are added, and the mixture is kept warm for 1-2 hours. The mixture is cooled to 33-38°C, triethylamine is added, and the mixture is kept warm for 10-20 minutes. A mixture of ethylenediamine, tetraethylenepentamine, and deionized water is poured in, and the mixture is emulsified in an ice-water bath for 10-15 minutes and rotary evaporated to obtain a soybean oil-based self-healing waterborne polyurethane.

[0020] Furthermore, the mass ratio of the epoxy compound containing Si-O segments to the zinc oxide composite microspheres is 1:1.5.

[0021] Furthermore, the mass ratio of soybean oil-based polyol, polytetramethylene ether glycol, isophorone diisocyanate, 2,2-bis(hydroxymethyl)propionic acid, epoxy compound containing Si-O chain segment, and dithiodiethanol is 8:3:10.2:1:2:1.8.

[0022] Furthermore, the preparation of the epoxy compound containing Si-O segments comprises the following steps:

[0023] Under a nitrogen atmosphere, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and ethanol were mixed, epichlorohydrin was added, the temperature was raised to 53-57°C and kept warm for 4-5 hours, cooled to 28-32°C, sodium hydroxide solution was added, and the temperature was kept warm for 2 hours. The mixture was filtered, rotary evaporated, washed, and dried to obtain an epoxy compound containing Si-O segments.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention provides a high-strength antibacterial plastic packaging bottle and a preparation method thereof. Through component and process design, a green and environmentally friendly plastic packaging bottle with high strength, good antibacterial properties and a self-repairing surface is prepared.

[0026] The present invention is based on the concept of green environmental protection, selects degradable polylactic acid as the base material of plastic packaging bottles, and in order to solve the brittleness problem of polylactic acid, polybutylene succinate with high tension, strong toughness and excellent biocompatibility is blended as a toughening agent. In order to improve the compatibility of polylactic acid and polybutylene succinate, epoxy soybean oil is selected as a compatibilizer. In order to improve the antibacterial property of plastic packaging bottles, zinc oxide and tea polyphenols are selected as antibacterial agents to achieve a broad-spectrum antibacterial effect. In order to improve the uniformity and thermal stability of the dispersion of zinc oxide and tea polyphenols in plastic packaging bottles and achieve a long-lasting antibacterial effect, the present invention first uses polyoxyethylene polyoxypropylene ether block copolymer and sucrose Mesoporous nano-zinc oxide was prepared by a hydrothermal method using zinc oxide as a template agent. The natural antibacterial agent tea polyphenols was carried on the mesoporous nano-zinc oxide as a carrier. Then, under the action of the cross-linking agent glutaraldehyde, it was coated with biocompatible and easily degradable carboxymethyl chitosan to obtain zinc oxide composite microspheres, overcoming the problem of uncontrolled release of tea polyphenols. Then, under the catalysis of zinc acetate, epoxy compounds containing Si-O segments were grafted to obtain composite zinc oxide with dynamic ester bonds and epoxy groups. The epoxy groups of the composite zinc oxide were used to react with the terminal hydroxyl / carboxyl groups of polylactic acid and polybutylene succinate during the melt blending process to enhance the bonding strength between the composite zinc oxide and the base material, thereby achieving a long-lasting antibacterial effect.

[0027] The epoxy compound containing Si-O segments is prepared from 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and epichlorohydrin. Introducing the epoxy compound containing Si-O segments into the composite zinc oxide helps to improve the toughness of the plastic bottle.

[0028] In order to give the plastic bottle surface excellent resistance to mechanical damage and improve the sealing and antibacterial durability of the plastic bottle, a protective coating is prepared using composite zinc oxide and soybean oil-based self-healing water-based polyurethane, which is coated on the surface of the base component to construct a green, antibacterial, anti-fouling and self-healing surface.

[0029] By hydroxyl ring-opening epoxidized soybean oil, polyethylene glycol antifouling groups are coupled on the side chain to obtain soybean oil-based polyol, which is then used as raw materials with polytetramethylene ether glycol and isophorone diisocyanate to prepare polyurethane prepolymer. Under the action of a catalyst, 2,2-bis(hydroxymethyl)propionic acid is used as a hydrophilic chain extender, epoxy compounds containing Si-O segments are used as modifiers, 1,4-butanediol and dithiodiethanol are used as end-capping agents, triethylamine is used as a neutralizer, and ethylenediamine and tetraethylenepentamine are used as amine cross-linking agents to prepare soybean oil-based self-healing water-based polyurethane. Then, composite zinc oxide is used as a filler to give the base component a green, environmentally friendly, antibacterial, antifouling and self-healing surface, greatly extending the service life of plastic bottles. DETAILED DESCRIPTION

[0030] The following will provide a clear and complete description of the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, and back, such directional indications are only used to explain a specific posture, such as the relative position relationship between components, the movement status, etc. If the specific posture changes, the directional indication will also change accordingly. In addition, the technical solutions between the various embodiments may be combined with each other, but they must be based on the premise that they can be implemented by ordinary technicians in this field. If the combination of technical solutions is mutually inconsistent or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0032] The technical solutions of the present invention are further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely used to explain the present invention and are not intended to limit the present invention.

[0033] Example 1: A method for preparing a high-strength antibacterial plastic packaging bottle, comprising the following steps:

[0034] S1: polylactic acid, polybutylene succinate, epoxy soybean oil, and composite zinc oxide are mixed, extruded into granules, and blow-molded to obtain a base part;

[0035] The mass ratio of polylactic acid, polybutylene succinate, epoxy soybean oil and composite zinc oxide is 79:10:4:7;

[0036] The preparation of the composite zinc oxide comprises the following steps:

[0037] (1) 2.2 g of zinc nitrate hexahydrate, 12 g of carbodiamide, and 200 mL of deionized water were mixed, 0.72 g of polyoxyethylene polyoxypropylene ether block copolymer and 0.72 g of sucrose were added, the pH of the solution was adjusted to 4, stirred for 1 h, transferred to a reactor, heated to 88 ° C and kept warm for 24 h, cooled, centrifuged, washed, dried, and extracted with anhydrous ethanol using a Soxhlet extractor for 12 h, dried, and kept warm at 270 ° C for 1.5 h to obtain mesoporous nano zinc oxide;

[0038] (2) 6 g of tea polyphenols and 60 mL of deionized water were mixed, and a mixture of 1 g of mesoporous nano zinc oxide and 40 mL of deionized water was added, and ultrasonic stirring was performed for 1 min. Vacuum stirring was performed for 20 min, and a mixture of 2 g of carboxymethyl chitosan and 80 mL of deionized water was added. Ultrasonic dispersion was performed for 10 min, and a mixture of 300 mL of liquid paraffin and 100 mL of Span-80 was added. The mixture was stirred for 20 min, and 4 mL of a 7% glutaraldehyde solution was added. The mixture was heated to 40 ° C and kept warm for 2 h. The pH value of the solution was adjusted to 9, and the mixture was heated to 68 ° C and kept warm for 3 h. The mixture was washed with acetone, petroleum ether, and anhydrous ethanol in sequence, and dried to obtain zinc oxide composite microspheres.

[0039] (3) 2 g of epoxy compound containing Si-O segments, 3 g of zinc oxide composite microspheres, and 30 mL of ethanol were mixed, heated to 88 °C, 0.13 g of zinc acetate was added, stirred for 1 h, cooled, washed, and dried to obtain composite zinc oxide;

[0040] The preparation of the epoxy compound containing Si-O segments comprises the following steps:

[0041] Under a nitrogen atmosphere, 1.4 mL of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and 50 mL of ethanol were mixed, 15.6 mL of epichlorohydrin was added, the temperature was raised to 53°C and kept warm for 5 h, cooled to 28°C, 2 g of 50% sodium hydroxide solution was added, the temperature was continued to be kept warm for 2 h, filtered, rotary evaporated, washed, and dried to obtain an epoxy compound containing Si-O segments;

[0042] S2: Preparation of protective coatings using composite zinc oxide and soybean oil-based self-healing waterborne polyurethane;

[0043] The mass ratio of composite zinc oxide and soybean oil-based self-healing waterborne polyurethane in the protective coating is 9%;

[0044] The preparation of soybean oil-based self-healing waterborne polyurethane includes the following steps:

[0045] 1) Mix 5 g of polyethylene glycol monomethyl ether and 0.01 g of tetrafluoroboric acid, heat to 60° C. and keep warm for 40 min, add 6.5 g of epoxidized soybean oil, continue to keep warm for 110 min, add to 5 mL of ethyl acetate, add 50 mL of saturated brine to extract, dry with anhydrous magnesium sulfate, filter, and rotary evaporate to obtain soybean oil-based polyol;

[0046] 2) Under nitrogen atmosphere, 8g soybean oil-based polyol, 3g polytetramethylene glycol, 10.2g isophorone diisocyanate were mixed, heated to 75℃ and kept warm for 12min, 1g 2,2-bis(hydroxymethyl)propionic acid, 3 drops of dibutyltin dilaurate, 5mL N,N-dimethylformamide were added, and the mixture was kept warm for 1h, 2g of Si-O segment epoxy compound, 5mL N,N-dimethylformamide were added, and the mixture was kept warm for 1h. h, cooled to 55 ° C, added 0.6 g of 1,4-butanediol, 1.8 g of dithiodiethanol, and 6 mL of butanone, and continued to keep warm for 1 h, cooled to 33 ° C, added 0.1 g of triethylamine and kept warm for 10 min, poured into a mixture of 0.2 g of ethylenediamine, 0.2 g of tetraethylenepentamine, and deionized water, and emulsified at 3000 r / min for 10 min in an ice water bath, and rotary evaporated to obtain a soybean oil-based self-healing waterborne polyurethane with a solid content of 18%;

[0047] S3: coating the protective coating on the surface of the base member and curing the coating to obtain a high-strength antibacterial plastic packaging bottle; the curing working conditions are: keeping the temperature at 90° C. for 2 hours.

[0048] Example 2: A method for preparing a high-strength antibacterial plastic packaging bottle, comprising the following steps:

[0049] S1: polylactic acid, polybutylene succinate, epoxy soybean oil, and composite zinc oxide are mixed, extruded into granules, and blow-molded to obtain a base part;

[0050] The mass ratio of polylactic acid, polybutylene succinate, epoxy soybean oil and composite zinc oxide is 79:10:4:7;

[0051] The preparation of the composite zinc oxide comprises the following steps:

[0052] (1) 2.2 g of zinc nitrate hexahydrate, 12 g of carbodiamide, and 200 mL of deionized water were mixed, 0.72 g of polyoxyethylene polyoxypropylene ether block copolymer and 0.72 g of sucrose were added, the pH of the solution was adjusted to 4.5, stirred for 1.5 h, transferred to a reactor, heated to 90 ° C and kept warm for 23 h, cooled, centrifuged, washed, dried, and extracted with anhydrous ethanol using a Soxhlet extractor for 12 h, dried, and kept warm at 270 ° C for 1.5 h to obtain mesoporous nano zinc oxide;

[0053] (2) 6 g of tea polyphenols and 60 mL of deionized water were mixed, and a mixture of 1 g of mesoporous nano zinc oxide and 40 mL of deionized water was added, and ultrasonic stirring was performed for 2 min. Vacuum stirring was performed for 25 min, and a mixture of 2 g of carboxymethyl chitosan and 80 mL of deionized water was added. Ultrasonic dispersion was performed for 13 min, and a mixture of 300 mL of liquid paraffin and 100 mL of Span-80 was added. The mixture was stirred for 25 min, and 4 mL of 7% glutaraldehyde solution was added. The mixture was heated to 45 ° C and kept warm for 1.5 h. The pH value of the solution was adjusted to 9.5, and the mixture was heated to 70 ° C and kept warm for 2.5 h. The mixture was washed with acetone, petroleum ether, and anhydrous ethanol in sequence, and dried to obtain zinc oxide composite microspheres.

[0054] (3) 2 g of epoxy compound containing Si-O segments, 3 g of zinc oxide composite microspheres, and 30 mL of ethanol were mixed, heated to 90°C, 0.13 g of zinc acetate was added, stirred for 1.5 h, cooled, washed, and dried to obtain composite zinc oxide;

[0055] The preparation of the epoxy compound containing Si-O segments comprises the following steps:

[0056] Under a nitrogen atmosphere, 1.4 mL of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and 50 mL of ethanol were mixed, 15.6 mL of epichlorohydrin was added, the temperature was raised to 55°C and kept warm for 4.5 h, cooled to 30°C, 2 g of 50% sodium hydroxide solution was added, the temperature was continued to be kept warm for 2 h, filtered, rotary evaporated, washed, and dried to obtain an epoxy compound containing Si-O segments;

[0057] S2: Preparation of protective coatings using composite zinc oxide and soybean oil-based self-healing waterborne polyurethane;

[0058] The mass ratio of composite zinc oxide and soybean oil-based self-healing waterborne polyurethane in the protective coating is 12%;

[0059] The preparation of soybean oil-based self-healing waterborne polyurethane includes the following steps:

[0060] 1) Mix 5 g of polyethylene glycol monomethyl ether and 0.01 g of tetrafluoroboric acid, heat to 60-65° C. and keep warm for 30-40 min, add 6.5 g of epoxidized soybean oil, continue to keep warm for 110-120 min, add to 5 mL of ethyl acetate, add 50 mL of saturated brine to extract, dry with anhydrous magnesium sulfate, filter, and rotary evaporate to obtain soybean oil-based polyol;

[0061] 2) Under nitrogen atmosphere, 8 g soybean oil-based polyol, 3 g polytetramethylene glycol, and 10.2 g isophorone diisocyanate were mixed and heated to 78°C for 10 min. 1 g 2,2-bis(hydroxymethyl)propionic acid, 3 drops of dibutyltin dilaurate, and 5 mL N,N-dimethylformamide were added and the mixture was heated for another 1.5 h. 2 g of a Si-O segment-containing epoxy compound and 5 mL N,N-dimethylformamide were added and the mixture was heated for another 1.5 h. 5h, cooled to 56°C, added 0.6g 1,4-butanediol, 1.8g dithiodiethanol, and 6mL butanone, continued to keep warm for 1.5h, cooled to 35°C, added 0.1g triethylamine and kept warm for 15min, poured into a mixture of 0.2g ethylenediamine, 0.2g tetraethylenepentamine, and deionized water, and emulsified at 3000r / min for 13min in an ice water bath, and rotary evaporated to obtain a soybean oil-based self-healing waterborne polyurethane with a solid content of 18%;

[0062] S3: coating the protective coating on the surface of the base member and curing the coating to obtain a high-strength antibacterial plastic packaging bottle; the curing working conditions are: keeping the temperature at 100° C. for 1.5 hours.

[0063] Example 3: A method for preparing a high-strength antibacterial plastic packaging bottle, comprising the following steps:

[0064] S1: polylactic acid, polybutylene succinate, epoxy soybean oil, and composite zinc oxide are mixed, extruded into granules, and blow-molded to obtain a base part;

[0065] The mass ratio of polylactic acid, polybutylene succinate, epoxy soybean oil and composite zinc oxide is 79:10:4:7;

[0066] The preparation of the composite zinc oxide comprises the following steps:

[0067] (1) 2.2 g of zinc nitrate hexahydrate, 12 g of carbodiamide, and 200 mL of deionized water were mixed, 0.72 g of polyoxyethylene polyoxypropylene ether block copolymer and 0.72 g of sucrose were added, the pH of the solution was adjusted to 5, stirred for 2 h, transferred to a reactor, heated to 92 ° C and kept warm for 22 h, cooled, centrifuged, washed, dried, and extracted with anhydrous ethanol using a Soxhlet extractor for 12 h, dried, and kept warm at 270 ° C for 1.5 h to obtain mesoporous nano zinc oxide;

[0068] (2) 6 g of tea polyphenols and 60 mL of deionized water were mixed, and a mixture of 1 g of mesoporous nano zinc oxide and 40 mL of deionized water was added, and ultrasonic stirring was performed for 3 min. Vacuum stirring was performed for 30 min, and a mixture of 2 g of carboxymethyl chitosan and 80 mL of deionized water was added. Ultrasonic dispersion was performed for 15 min, and a mixture of 300 mL of liquid paraffin and 100 mL of Span-80 was added. The mixture was stirred for 30 min, and 4 mL of a 7% glutaraldehyde solution was added. The mixture was heated to 50 ° C and kept warm for 1 h. The pH value of the solution was adjusted to 10, and the mixture was heated to 72 ° C and kept warm for 2 h. The mixture was washed with acetone, petroleum ether, and anhydrous ethanol in sequence, and dried to obtain zinc oxide composite microspheres.

[0069] (3) 2 g of an epoxy compound containing Si-O segments, 3 g of zinc oxide composite microspheres, and 30 mL of ethanol were mixed, heated to 92°C, 0.13 g of zinc acetate was added, stirred for 2 h, cooled, washed, and dried to obtain composite zinc oxide;

[0070] The preparation of the epoxy compound containing Si-O segments comprises the following steps:

[0071] Under a nitrogen atmosphere, 1.4 mL of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and 50 mL of ethanol were mixed, 15.6 mL of epichlorohydrin was added, the temperature was raised to 57°C and kept warm for 4 h, then cooled to 32°C, 2 g of 50% sodium hydroxide solution was added, and the temperature was kept warm for another 2 h. The mixture was filtered, rotary evaporated, washed, and dried to obtain an epoxy compound containing Si-O segments.

[0072] S2: Preparation of protective coatings using composite zinc oxide and soybean oil-based self-healing waterborne polyurethane;

[0073] The mass ratio of composite zinc oxide and soybean oil-based self-healing waterborne polyurethane in the protective coating is 9-14%;

[0074] The preparation of soybean oil-based self-healing waterborne polyurethane includes the following steps:

[0075] 1) Mix 5 g of polyethylene glycol monomethyl ether and 0.01 g of tetrafluoroboric acid, heat to 65° C. and keep warm for 40 min, add 6.5 g of epoxidized soybean oil, continue to keep warm for 120 min, add to 5 mL of ethyl acetate, add 50 mL of saturated brine to extract, dry with anhydrous magnesium sulfate, filter, and rotary evaporate to obtain soybean oil-based polyol;

[0076] 2) Under nitrogen atmosphere, 8g soybean oil-based polyol, 3g polytetramethylene glycol, and 10.2g isophorone diisocyanate were mixed, heated to 80°C and kept warm for 8min, 1g 2,2-bis(hydroxymethyl)propionic acid, 3 drops of dibutyltin dilaurate, and 5mL N,N-dimethylformamide were added, and the mixture was kept warm for 2h. A mixture of 2g of Si-O segment epoxy compound and 5mL N,N-dimethylformamide was added, and the mixture was kept warm for 2h. , cool to 57 ° C, add 0.6g 1,4-butanediol, 1.8g dithiodiethanol, and 6mL butanone, continue to keep warm for 2h, cool to 38 ° C, add 0.1g triethylamine and keep warm for 20min, pour in a mixture of 0.2g ethylenediamine, 0.2g tetraethylenepentamine, and deionized water, emulsify at 3000r / min for 15min in an ice water bath, and rotary evaporate to obtain a soybean oil-based self-healing waterborne polyurethane with a solid content of 18%;

[0077] S3: coating the protective coating on the surface of the base member and curing the coating to obtain a high-strength antibacterial plastic packaging bottle; the curing working conditions are: keeping the temperature at 110° C. for 1 hour.

[0078] Comparative Example 1: Taking Example 3 as the control group, mesoporous nano zinc oxide was used to replace the composite zinc oxide, and the other processes were normal.

[0079] Comparative Example 2: Example 3 was used as a control group, soybean oil-based polyol was not prepared, and other processes were normal.

[0080] Comparative Example 3: Example 3 was used as a control group, in which no Si-O segment-containing epoxy compound was prepared, and other processes were normal.

[0081] In the embodiment and the comparative example, the thickness of the base member is 0.8 mm, and the thickness of the protective coating formed after being coated on the surface of the base member and cured is 0.2 mm.

[0082] Sources of raw materials used (for demonstration purposes only):

[0083] Polylactic acid JS2894: Hubei Jusheng Technology Co., Ltd.; polybutylene succinate 05131: Dongguan Shenghao Plastic Raw Materials Co., Ltd.; epoxidized soybean oil 197: Zibo Lishuo Chemical Trading Co., Ltd.; polyoxyethylene polyoxypropylene ether block copolymer 2023: Shanxi Jinyang Pharmaceutical Excipients Co., Ltd.; 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane XK2342: Hubei Xinkang Pharmaceutical Chemical Co., Ltd.; tetrafluoroboric acid 16872-11-0: Hubei Chengfeng Chemical Co., Ltd.; zinc nitrate hexahydrate Z111703, carbodiimide U111897, sucrose S112228, tea polyphenols T418534, carboxymethyl chitosan C304738, liquid paraffin P304684, S pan-80S110840, glutaraldehyde G105905, epichlorohydrin E108182, polyethylene glycol monomethyl ether M109717, polytetramethylene ether glycol P117874, isophorone diisocyanate I109582, dibutyltin dilaurate D100274, N,N-dimethylformamide D111999, 2,2-bis(hydroxymethyl)propionic acid B104539, 1,4-butanediol B110391, triethylamine T103285, ethylenediamine E112132, dithiodiethanol B152479, tetraethylenepentamine T103795: Aladdin reagent; ethanol, acetone, petroleum ether, zinc acetate, sodium hydroxide, ethyl acetate, saline, magnesium sulfate, butanone, analytical grade: Sinopharm reagents.

[0084] Performance test: The plastic packaging bottles prepared in the examples and comparative examples were tested:

[0085] Tensile strength test: electronic universal testing machine was used for testing, sample length 80mm, width 40mm, test temperature 25℃, tensile rate 5mm / min; self-repair rate: scratch 1mm long, 2μm wide and 0.2mm deep on the sample surface, kept at 50℃ for 12h, and the scratch length was observed with an electron microscope. Self-repair rate = (L 划痕初始长度 -L 保温后划痕长度 ) / L 划痕初始长度 ×100%; Antimicrobial persistence: ATCC 6538 Staphylococcus aureus was used as the test strain, and the test was conducted according to ISO 22196:2007 using the plate count method after 20 standard water washes. The results are shown in Table 1.

[0086] Table 1

[0087]

[0088] The present invention provides a high-strength antibacterial plastic packaging bottle and a preparation method thereof. Through component and process design, a green and environmentally friendly plastic packaging bottle with high strength, good antibacterial properties and a self-repairing surface is prepared. In Table 1, / indicates that the item has not been tested.

[0089] Comparing Example 3 with Comparative Examples 1 and 3, it can be seen that zinc oxide and tea polyphenols are selected as antibacterial agents to achieve a broad-spectrum antibacterial effect. In order to improve the uniformity and thermal stability of the dispersion of zinc oxide and tea polyphenols in plastic packaging bottles and achieve a lasting antibacterial effect, the present invention first uses polyoxyethylene polyoxypropylene ether block copolymer and sucrose as templates, adopts a hydrothermal method to prepare mesoporous nano zinc oxide, uses mesoporous nano zinc oxide as a carrier to carry the natural antibacterial agent tea polyphenols, and then, under the action of a cross-linking agent glutaraldehyde, uses biocompatible and easily degradable carboxymethyl chitosan to coat zinc oxide composite microspheres, thereby overcoming the problem of uncontrolled release of tea polyphenols; then, under the catalysis of zinc acetate, grafts an epoxy compound containing Si-O segments to obtain a composite zinc oxide having a dynamic ester bond and an epoxy group, and utilizes its epoxy group to react with the terminal hydroxyl / carboxyl groups of polylactic acid and polybutylene succinate during the melt blending process to enhance its bonding strength with the base material, thereby achieving a lasting antibacterial effect.

[0090] The epoxy compound containing Si-O segments is prepared from 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and epichlorohydrin. Introducing the epoxy compound containing Si-O segments into the composite zinc oxide helps to improve the toughness of the plastic bottle.

[0091] By comparing Example 3 with Comparative Examples 2 and 3, it can be seen that soybean oil-based polyol is obtained by coupling polyethylene glycol antifouling groups on the side chains through hydroxyl ring-opening epoxidation of soybean oil, and the soybean oil-based polyol is used as raw materials with polytetramethylene ether glycol and isophorone diisocyanate to prepare polyurethane prepolymer. Under the action of a catalyst, 2,2-bis(hydroxymethyl)propionic acid is used as a hydrophilic chain extender, an epoxy compound containing Si-O segments is used as a modifier, 1,4-butanediol and dithiodiethanol are used as end-capping agents, triethylamine is used as a neutralizing agent, and ethylenediamine and tetraethylenepentamine are used as amine cross-linking agents to prepare soybean oil-based self-healing water-based polyurethane. Then, composite zinc oxide is used as a filler to give the base component a green, environmentally friendly, antibacterial, antifouling and self-healing surface, thereby greatly extending the service life of the plastic bottle.

[0092] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the present invention specification under the inventive concept of the present invention, or any direct / indirect application in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a high-strength antibacterial plastic packaging bottle, characterized in that: The following steps are involved: S1: polylactic acid, polybutylene succinate, epoxy soybean oil, and composite zinc oxide are mixed, extruded into granules, and blow-molded to obtain a base part; S2: Preparation of protective coatings using composite zinc oxide and soybean oil-based self-healing waterborne polyurethane; S3: coating the protective coating on the surface of the base member and curing the coating to obtain a high-strength antibacterial plastic packaging bottle; The preparation of the composite zinc oxide comprises the following steps: (1) Zinc nitrate hexahydrate, carbamide, and deionized water were mixed, and polyoxyethylene polyoxypropylene ether block copolymer and sucrose were added. The pH of the solution was adjusted to 4-5, stirred for 1-2 hours, transferred to a reactor, heated to 88-92°C and kept warm for 22-24 hours, cooled, centrifuged, washed, and dried. A Soxhlet extractor was used to extract with anhydrous ethanol for 12 hours, dried, and kept warm at 270°C for 1.5 hours to obtain mesoporous nano zinc oxide. (2) Mix tea polyphenols and deionized water, add a mixture of mesoporous nano zinc oxide and deionized water, ultrasonically stir for 1-3 minutes, vacuum stir for 20-30 minutes, add a mixture of carboxymethyl chitosan and deionized water, ultrasonically disperse for 10-15 minutes, add a mixture of liquid paraffin and Span-80, stir for 20-30 minutes, add glutaraldehyde solution, heat to 40-50 ° C and keep warm for 1-2 hours, adjust the pH value of the solution to 9-10, heat to 68-72 ° C and keep warm for 2-3 hours, wash with acetone, petroleum ether and anhydrous ethanol in sequence, and dry to obtain zinc oxide composite microspheres; (3) Mix the epoxy compound containing Si-O segments, zinc oxide composite microspheres, and ethanol, heat to 88-92°C, add zinc acetate, stir for 1-2 hours, cool, wash, and dry to obtain composite zinc oxide; The preparation of the soybean oil-based self-repairing waterborne polyurethane comprises the following steps: 1) Mix polyethylene glycol monomethyl ether and tetrafluoroboric acid, heat to 60-65°C and keep warm for 30-40 minutes, add epoxidized soybean oil, continue to keep warm for 110-120 minutes, add to ethyl acetate, add saturated brine to extract, dry with anhydrous magnesium sulfate, filter, and rotary evaporate to obtain soybean oil-based polyol; 2) Under a nitrogen atmosphere, soybean oil-based polyol, polytetramethylene glycol, and isophorone diisocyanate are mixed, heated to 75-80°C and kept warm for 8-12 minutes, 2,2-bis(hydroxymethyl)propionic acid, dibutyltin dilaurate, and N,N-dimethylformamide are added, and the mixture is kept warm for 1-2 hours. A mixture of an epoxy compound containing an Si-O segment and N,N-dimethylformamide is added, and the mixture is kept warm for 1-2 hours. The mixture is cooled to 55-57°C, 1,4-butanediol, dithiodiethanol, and butanone are added, and the mixture is kept warm for 1-2 hours. The mixture is cooled to 33-38°C, triethylamine is added, and the mixture is kept warm for 10-20 minutes. A mixture of ethylenediamine, tetraethylenepentamine, and deionized water is poured into the mixture, and the mixture is emulsified in an ice-water bath for 10-15 minutes, and rotary evaporated to obtain a soybean oil-based self-healing waterborne polyurethane; The preparation of the epoxy compound containing Si-O segments comprises the following steps: Under a nitrogen atmosphere, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and ethanol were mixed, epichlorohydrin was added, the temperature was raised to 53-57°C and kept warm for 4-5 hours, cooled to 28-32°C, sodium hydroxide solution was added, and the temperature was kept warm for 2 hours. The mixture was filtered, rotary evaporated, washed, and dried to obtain an epoxy compound containing Si-O segments.

2. The method for preparing a high-strength antibacterial plastic packaging bottle according to claim 1, characterized in that: The working conditions for curing are: keeping warm at 90-110℃ for 1-2h.

3. The method for preparing a high-strength antibacterial plastic packaging bottle according to claim 1, characterized in that: The mass ratio of polylactic acid, polybutylene succinate, epoxy soybean oil and composite zinc oxide is 79:10:4:

7.

4. The method for preparing a high-strength antibacterial plastic packaging bottle according to claim 1, characterized in that: In the preparation of composite zinc oxide, the mass ratio of epoxy compound containing Si-O chain segment and zinc oxide composite microspheres is 1:1.

5.

5. The method for preparing a high-strength antibacterial plastic packaging bottle according to claim 1, characterized in that: In the preparation of soybean oil-based self-healing waterborne polyurethane, the mass ratio of soybean oil-based polyol, polytetramethylene ether glycol, isophorone diisocyanate, 2,2-bis(hydroxymethyl)propionic acid, epoxy compound containing Si-O chain segment, and dithiodiethanol is 8:3:10.2:1:2:1.

8.

6. A high-strength antibacterial plastic packaging bottle, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 5.

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