阅读说明：本技术 一种高阻隔抗菌性纳米银-石墨烯改性聚乳酸及其制法 (High-barrier antibacterial nano silver-graphene modified polylactic acid and preparation method thereof ) 是由 丁文华 于 2020-06-04 设计创作，主要内容包括：本发明涉及聚乳酸抗菌技术领域,且公开了一种高阻隔抗菌性纳米银-石墨烯改性聚乳酸,包括以下配方原料及组分：纳米银负载氨基功能化石墨烯、丁二酸酐接枝聚乳酸。氨基功能化石墨烯与银离子发生良好的络合作用,通过原位还原法,使生成的纳米银均匀分散和沉积在氧化石墨烯的表面,减少纳米银的团聚和聚集,DL-丙交酯开环聚合得到的聚乳酸与顺丁烯二酸酐进行反应,得到丁二酸酐接枝聚乳酸,再与功能化石墨烯的氨基进行N-酰化反应,纳米银赋予了聚乳酸优异的抗菌性能,分散均匀的石墨烯纳米粒子填充进聚乳酸基体中的间隙中,可以提高聚乳酸包装材料对空气和水分的阻隔性能,增强对细菌或真菌等微生物的抑制能力。(The invention relates to the technical field of polylactic acid antibiosis, and discloses high-barrier antibacterial nano silver-graphene modified polylactic acid which comprises the following formula raw materials and components: the nano-silver-loaded amino functionalized graphene and succinic anhydride grafted polylactic acid. Amino functionalized graphene and silver ions generate good complexation, generated nano silver is uniformly dispersed and deposited on the surface of graphene oxide through an in-situ reduction method, the aggregation and aggregation of the nano silver are reduced, polylactic acid obtained through DL-lactide ring-opening polymerization reacts with maleic anhydride to obtain succinic anhydride grafted polylactic acid, and then the succinic anhydride grafted polylactic acid and amino of the functionalized graphene perform N-acylation reaction, the nano silver endows the polylactic acid with excellent antibacterial performance, and uniformly dispersed graphene nano particles are filled into gaps in a polylactic acid matrix, so that the barrier performance of the polylactic acid packaging material to air and water can be improved, and the inhibition capacity to microorganisms such as bacteria or fungi is enhanced.)

1. The high-barrier antibacterial nano silver-graphene modified polylactic acid comprises the following formula raw materials in parts by weight and components, and is characterized in that: the nano-silver-loaded amino functionalized graphene and the succinic anhydride grafted polylactic acid have a mass ratio of 0.5-4: 100.

2. The high-barrier antibacterial nano silver-graphene modified polylactic acid according to claim 1, is characterized in that: the preparation method of the high-barrier antibacterial nano silver-graphene modified polylactic acid comprises the following steps:

(1) adding graphene oxide into distilled water, placing the mixture into an ultrasonic device, performing ultrasonic dispersion treatment, adding ammonia water to adjust the pH value of the solution to 9-11, adding triethylene tetramine, heating to 70-90 ℃ in a nitrogen atmosphere, reacting for 2-4h, centrifuging, washing and drying to prepare amino functionalized graphene;

(2) adding amino functionalized graphene into a distilled aqueous solvent, uniformly dispersing by using ultrasonic waves, adding polyvinylpyrrolidone and silver nitrate, stirring for 2-6h under a dark condition, adding sodium citrate, heating to 90-110 ℃, stirring and refluxing for 1-3h under the dark condition, filtering, washing and drying to prepare nano-silver loaded amino functionalized graphene;

(3) adding DL-lactide, maleic anhydride and dibenzoyl peroxide into an acetone solvent, heating to 100-120 ℃, stirring at a constant speed for reflux reaction for 1-2 hours, placing the solution in an ice-water bath for cooling, adding tetrahydrofuran for dissolving, then adding distilled water until a large amount of precipitate is separated out, filtering to remove the solvent, washing a solid product by using distilled water and diethyl ether, and drying to prepare the succinic anhydride grafted polylactic acid;

(4) adding a tetrahydrofuran solvent and nano-silver loaded amino functionalized graphene into a reaction bottle, adding succinic anhydride grafted polylactic acid after uniform ultrasonic dispersion, stirring at a constant speed at 5-20 ℃ for reaction for 1-3h, pouring the solution into a film forming mold for natural casting, drying to remove the solvent, and preparing the high-barrier antibacterial nano-silver-graphene modified polylactic acid.

3. The high-barrier antibacterial nano silver-graphene modified polylactic acid according to claim 2, is characterized in that: the mass ratio of the triethylene tetramine to the graphene oxide in the step (1) is 50-80: 1.

4. The high-barrier antibacterial nano silver-graphene modified polylactic acid according to claim 2, is characterized in that: the ultrasonic device in the step (1) comprises an ultrasonic device, the ultrasonic device is provided with an ultrasonic probe, a base is arranged below the inside of the ultrasonic device, a lifting frame is movably connected above the base, an object stage is arranged above the lifting frame, and a reaction bottle is arranged above the object stage.

5. The high-barrier antibacterial nano silver-graphene modified polylactic acid according to claim 2, is characterized in that: the mass ratio of the amino functionalized graphene, the polyvinylpyrrolidone, the silver nitrate and the sodium citrate in the step (2) is 100-200:140-180:100: 150-200.

6. The high-barrier antibacterial nano silver-graphene modified polylactic acid according to claim 2, is characterized in that: the mass ratio of DL-lactide, maleic anhydride and dibenzoyl peroxide in the step (3) is 100:1-2: 0.5-0.7.

Technical Field

The invention relates to the technical field of polylactic acid antibiosis, in particular to high-barrier antibacterial nano silver-graphene modified polylactic acid and a preparation method thereof.

Background

The antibacterial agent is a functional material which endows high molecular polymers with the function of inhibiting and killing bacteria, fungi and other microorganisms, mainly comprises inorganic antibacterial agents and organic antibacterial agents, such as zinc oxide, titanium dioxide, nano silver, quaternary ammonium salt compounds and the like, wherein the nano silver has excellent antibacterial property and broad spectrum, is not easy to cause the bacteria to generate drug resistance, and is widely applied.

Polylactic acid is a high polymer material with safety, non-toxicity, biodegradability and biocompatibility, can be made into a fiber material, and can be widely applied to the fields of packaging materials and biomedicine.

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides the high-barrier antibacterial nano silver-graphene modified polylactic acid and the preparation method thereof, solves the problems of poor barrier property and antibacterial property of the traditional polylactic acid, and simultaneously solves the problem that nano silver is easy to agglomerate in the polylactic acid.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: the high-barrier antibacterial nano silver-graphene modified polylactic acid comprises the following formula raw materials in parts by weight: the nano-silver-loaded amino functionalized graphene and the succinic anhydride grafted polylactic acid have a mass ratio of 0.5-4: 100.

Preferably, the preparation method of the high-barrier antibacterial nano silver-graphene modified polylactic acid comprises the following steps:

(1) adding a distilled water solvent and graphene oxide into a reaction bottle, placing the reaction bottle in an ultrasonic device, performing ultrasonic dispersion treatment, adding ammonia water to adjust the pH value of the solution to 9-11, adding triethylene tetramine, heating the solution to 70-90 ℃ in a nitrogen atmosphere, stirring at a constant speed for reaction for 2-4h, performing centrifugal separation on the solution to remove the solvent, washing a solid product by using distilled water and ethanol, and drying to prepare the amino functionalized graphene.

(2) Adding a distilled water solvent and amino functionalized graphene into a reaction bottle, uniformly dispersing by ultrasonic, adding polyvinylpyrrolidone and silver nitrate, uniformly stirring for 2-6h under a dark condition, adding sodium citrate, heating to 90-110 ℃, uniformly stirring under a dark condition, refluxing for 1-3h, filtering the solution to remove the solvent, washing the solid product by using distilled water and ethanol, and drying to prepare the nano-silver loaded amino functionalized graphene.

(3) Adding an acetone solvent, DL-lactide, maleic anhydride and dibenzoyl peroxide into a reaction bottle, heating to 120 ℃ and stirring at a constant speed for reflux reaction for 1-2 hours, placing the solution in an ice-water bath for cooling, adding tetrahydrofuran for dissolving, then adding distilled water until a large amount of precipitate is separated out, filtering to remove the solvent, washing a solid product by using distilled water and diethyl ether, and drying to prepare the succinic anhydride grafted polylactic acid.

(4) Adding a tetrahydrofuran solvent and nano-silver loaded amino functionalized graphene into a reaction bottle, adding succinic anhydride grafted polylactic acid after uniform ultrasonic dispersion, stirring at a constant speed at 5-20 ℃ for reaction for 1-3h, pouring the solution into a film forming mold for natural casting, drying to remove the solvent, and preparing the high-barrier antibacterial nano-silver-graphene modified polylactic acid.

Preferably, the mass ratio of the triethylene tetramine to the graphene oxide in the step (1) is 50-80: 1.

Preferably, the ultrasonic device in the step (1) comprises an ultrasonic device, the ultrasonic device is provided with an ultrasonic probe, a base is arranged below the inside of the ultrasonic device, a lifting frame is movably connected above the base, an objective table is arranged above the lifting frame, and a reaction bottle is arranged above the objective table.

Preferably, the mass ratio of the amino functionalized graphene, the polyvinylpyrrolidone, the silver nitrate and the sodium citrate in the step (2) is 100-200:140-180:100: 150-200.

Preferably, the mass ratio of the DL-lactide, the maleic anhydride and the dibenzoyl peroxide in the step (3) is 100:1-2: 0.5-0.7.

(III) advantageous technical effects

Compared with the prior art, the invention has the following beneficial technical effects:

according to the high-barrier antibacterial nano silver-graphene modified polylactic acid, active amino of triethylene tetramine reacts with epoxy groups of graphene oxide to obtain amino functionalized graphene, the amino and silver ions generate good complexation, the silver ions are uniformly adsorbed to the surface of the graphene oxide, the nano silver loaded amino functionalized graphene is prepared by an in-situ reduction method, the nano silver is uniformly dispersed and deposited on the surface of the graphene oxide, the aggregation and aggregation phenomena of the nano silver can be reduced, under the action of dibenzoyl peroxide, hydrogen atoms on alpha carbon atoms of polylactic acid obtained by DL-lactide ring-opening polymerization and alkenyl groups of maleic anhydride perform addition reaction to obtain succinic anhydride grafted polylactic acid, acid anhydride groups perform N-acylation reaction with the amino groups of the nano silver loaded amino functionalized graphene, and the nano silver-graphene is grafted to molecular chains of the polylactic acid through chemical covalent bonds, the interfacial compatibility of the nano silver-graphene and the polylactic acid is obviously improved, the nano silver and the graphene are prevented from agglomerating in the polylactic acid, the polylactic acid is endowed with excellent antibacterial performance by the trace nano silver, and the uniformly dispersed graphene nano particles are filled into gaps in a polylactic acid matrix, so that the permeation of air and moisture can be inhibited, the barrier property of the polylactic acid packaging material can be improved, and the inhibition capability on microorganisms such as bacteria or fungi is enhanced.

Drawings

FIG. 1 is a schematic front view of an ultrasound device;

fig. 2 is an enlarged schematic view of the crane.

1-an ultrasonic device; 2-an ultrasonic device; 3-an ultrasonic probe; 4-a base; 5, lifting the rack; 6-an objective table; 7-reaction flask.

Detailed Description

To achieve the above object, the present invention provides the following embodiments and examples: the high-barrier antibacterial nano silver-graphene modified polylactic acid comprises the following formula raw materials in parts by weight: the nano-silver-loaded amino functionalized graphene and the succinic anhydride grafted polylactic acid have a mass ratio of 0.5-4: 100.

The preparation method of the high-barrier antibacterial nano silver-graphene modified polylactic acid comprises the following steps:

(1) adding distilled hydrosolvent and graphene oxide into a reaction bottle, placing the reaction bottle in an ultrasonic device, wherein the ultrasonic device comprises an ultrasonic instrument, the ultrasonic instrument is provided with an ultrasonic probe, a base is arranged below the inner part of the ultrasonic device, a lifting frame is movably connected above the base, an object stage is arranged above the lifting frame, the reaction bottle is arranged above the object stage, ultrasonic dispersion treatment is carried out, ammonia water is added to adjust the pH value of the solution to 9-11, triethylene tetramine is added, the mass ratio of the triethylene tetramine to the graphene oxide is 50-80:1, the solution is heated to 70-90 ℃ in a nitrogen atmosphere, stirring at a constant speed is carried out for reaction for 2-4h, the solution is centrifugally separated to remove the solvent, and distilled water and ethanol are used for washing and drying the solid product.

(2) Adding a distilled water solvent and amino functionalized graphene into a reaction bottle, uniformly dispersing by ultrasonic, adding polyvinylpyrrolidone and silver nitrate, uniformly stirring for 2-6h under a dark condition, adding sodium citrate, heating to 90-110 ℃ under the dark condition, uniformly stirring for 1-3h under the dark condition, carrying out reflux reaction for 1-3h, washing a solid product by using distilled water and ethanol, and drying to obtain the nano-silver loaded amino functionalized graphene.

(3) Adding an acetone solvent, DL-lactide, maleic anhydride and dibenzoyl peroxide into a reaction bottle, wherein the mass ratio of the acetone solvent to the DL-lactide to the maleic anhydride to the dibenzoyl peroxide is 100:1-2:0.5-0.7, heating to 100-.

(4) Adding a tetrahydrofuran solvent and nano-silver loaded amino functionalized graphene into a reaction bottle, adding succinic anhydride grafted polylactic acid after uniform ultrasonic dispersion, stirring at a constant speed at 5-20 ℃ for reaction for 1-3h, pouring the solution into a film forming mold for natural casting, drying to remove the solvent, and preparing the high-barrier antibacterial nano-silver-graphene modified polylactic acid.