阅读说明：本技术 一种抗菌型可降解聚合物及其制备方法与应用 (Antibacterial degradable polymer and preparation method and application thereof ) 是由 席曼 金晶 姜旸 于 2019-09-25 设计创作，主要内容包括：本发明公开了一种抗菌型可降解聚合物及其制备方法与应用,通过采用旋涂或静电纺丝法制备C-PPC膜,并利用紫外接枝技术将SBMA和MA接枝至其表面以实现羧基的引入,最后再将包括抗菌肽(C)、溶菌酶(LYZ)的一种或两种活性因子通过静电相互作用结合到C-PPC-g-P(SBMA-co-MA)表面,从而得到具有广谱抗菌性的可降解聚合物。本发明公开的抗菌型可降解聚合物在制备过程中避免了增塑剂和有机溶剂的使用,具有可生物降解、抗菌性好的特点。因此,非常适合在食品包装,特别是食品保鲜膜中应用。(The invention discloses an antibacterial degradable polymer and a preparation method and application thereof, wherein a C-PPC film is prepared by adopting a spin coating or electrostatic spinning method, SBMA and MA are grafted to the surface of the C-PPC film by utilizing an ultraviolet grafting technology to realize the introduction of carboxyl, and finally one or two active factors comprising antibacterial peptide (C) and Lysozyme (LYZ) are combined to the surface of C-PPC-g-P (SBMA-co-MA) through electrostatic interaction, so that the degradable polymer with broad-spectrum antibacterial property is obtained. The antibacterial degradable polymer disclosed by the invention avoids the use of plasticizers and organic solvents in the preparation process, and has the characteristics of biodegradability and good antibacterial property. Therefore, the method is very suitable for food packaging, in particular to food preservative films.)

1. The preparation method of the antibacterial degradable polymer is characterized by comprising the following steps:

preparing chlorinated polypropylene carbonate (C-PPC) solution into a C-PPC film by a film forming process;

II, carrying out plasma treatment on the C-PPC membrane obtained in the step I, and carrying out ultraviolet grafting reaction on the C-PPC membrane subjected to the plasma treatment and Methacrylic Acid (MA) and methacrylic acid betaine (SBMA) molecules to obtain C-PPC-g-P (SBMA-co-MA);

and III, combining the C-PPC-g-P (SBMA-co-MA) obtained in the step II with an active factor to finally obtain the antibacterial degradable polymer.

2. The method for preparing an antibacterial degradable polymer according to claim 1, wherein in the step I, the method for preparing the C-PPC film specifically comprises the following steps:

i-1, preparing a C-PPC film from a C-PPC solution with the mass concentration of 8-13% by a film forming process;

and I-2, placing the C-PPC membrane obtained in the step I-1 in a vacuum oven to dry at room temperature to constant weight.

3. The method for preparing an antibacterial degradable polymer according to claim 2, wherein in the step I-1, the film forming process comprises spin coating or electrospinning.

4. The method for preparing an antibacterial degradable polymer according to claim 1, wherein in the step II, the method for preparing C-PPC-g-P (SBMA-co-MA) specifically comprises:

II-1, putting the constant-weight C-PPC film obtained in the step I into plasma, setting the power to be 100W, and treating for 60-90 s;

II-2, preparing an aqueous solution of MA-SBMA, wherein MA: SBMA: the weight ratio of water is 1:1: 4;

II-3, dropwise adding the solution prepared in the step II-2 on the C-PPC membrane treated by the plasma in the step II-1, and carrying out ultraviolet grafting treatment, wherein the ultraviolet wavelength is set to be 365nm, the power is set to be 300W, and the treatment time is set to be 5-30 min, so that C-PPC-g-P (SBMA-co-MA) is obtained.

5. The method of claim 1, wherein the active factor in step III comprises at least one of lysozyme LYZ and antimicrobial peptide C.

6. The method for preparing an antibacterial degradable polymer according to claim 5, wherein in the step III, the method for preparing an antibacterial degradable polymer specifically comprises:

III-1, preparing a single-activity factor/PBS solution with the concentration of 0.1-2 mg/mL;

III-2, placing the C-PPC-g-P (SBMA-co-MA) prepared in the step II in the active factor/PBS solution prepared in the step III-1, keeping the temperature at 37 +/-0.5 ℃ for 30-150 min, and washing for 3 times by using a PBS buffer solution to obtain the antibacterial degradable polymer with the single active factor;

III-3, repeating the steps III-1 to III-2 to obtain the antibacterial degradable polymer with multiple active factors.

7. The antibacterial degradable polymer obtained by the preparation method of the antibacterial degradable polymer according to claim 1 to 5, wherein the antibacterial degradable polymer comprises a C-PPC-g-P (SBMA-co-MA) -co-LYZ composite polymer, a C-PPC-g-P (SBMA-co-MA) -co-C composite polymer or a C-PPC-g-P (SBMA-co-MA) -co-LYZ/C composite polymer.

8. Use of the antibacterial degradable polymer according to claim 7 in the production of films or film products.

9. The use of an antibacterial degradable polymer according to claim 8 wherein said film or film product comprises a food preservative film.

Technical Field

The invention belongs to the field of polymer materials, and particularly relates to an antibacterial degradable polymer and a preparation method and application thereof.

Background

Food-derived spoilage and pathogenic microorganisms are the most important factors affecting food safety and quality, and food packaging is a key technical link for inhibiting food spoilage and pathogenic microorganisms in the field of food circulation. In the field of food packaging, polymer packaging is widely popular among consumers due to low price and convenience in use, and among them, plastic packaging represented by Polyethylene (PE), polyvinylidene chloride (PVDC), polyvinyl chloride (PVC) and the like is widely used for daily food packaging due to its advantages of high transparency and good tensile properties. However, with the widespread use of these polymeric packaging, a great deal of white contamination has attracted considerable attention based on its high stability against natural degradation. In particular, in the case of PVC, conventional polymer packaging uses a large amount of plasticizer during the production process, and the plasticizer is gradually released into food during the contact with the food, causing pollution to the food, thereby threatening human health. Therefore, the search for an environmentally friendly plastic that is naturally degradable and contains no plasticizer is the focus of research by those skilled in the art.

In addition, the traditional food packaging is mainly physically isolated, namely, the food packaging avoids putrefaction and standard exceeding caused by interference of external factors, and the inhibition of the internal factors of the food only depends on the antibacterial performance of the food additive. In recent years, with the concern of people on their own health and the increasing demand for food safety, active antimicrobial packaging has attracted great interest to those skilled in the art as an innovative method of preserving food quality.

The active antibacterial package is characterized in that active factors are firstly introduced into a polymer material matrix and then slowly and continuously released from a finished product package to realize a long-term antibacterial effect. At present, the application of natural biomacromolecules such as chitosan, starch, cellulose, sodium alginate and the like, or natural plants such as pomelo peel powder, tea polyphenol and the like to novel food packaging materials has been studied. However, the direct application of these materials in food packaging is limited by the disadvantages of poor water vapor barrier properties, severe brittleness, poor film forming properties, etc.

Therefore, the development of a biodegradable polymer packaging material with good antibacterial property, good gas barrier property and good mechanical properties has become a problem to be solved by those skilled in the art.

Disclosure of Invention

In view of the above, the present invention provides a method for preparing a biodegradable polymer with good antibacterial property, good gas barrier property, and good mechanical properties, aiming at the problems existing in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of an antibacterial degradable polymer comprises the following specific steps:

preparing a chlorinated polypropylene carbonate C-PPC solution into a C-PPC film by a film forming process;

II, carrying out plasma treatment on the C-PPC membrane obtained in the step I, and carrying out ultraviolet grafting reaction on the C-PPC membrane subjected to the plasma treatment and methacrylic acid MA and methacrylic acid betaine (SBMA) molecules to obtain C-PPC-g-P (SBMA-co-MA);

and III, combining the C-PPC-g-P (SBMA-co-MA) obtained in the step II with an active factor to finally obtain the antibacterial degradable polymer.

It is to be noted that the weight average molecular weight of the chlorinated polypropylene carbonate (C-PPC) is 2.62X 10⁵，M_w/M_n＝4.5。

Firstly, in consideration of the characteristics of biodegradability, flexibility, gas barrier property and the like of a polymer, the chlorinated polypropylene carbonate (C-PPC) is adopted as a polymer material matrix, and compared with PPC used in the prior art, the C-PPC has all excellent properties of the PPC and better bactericidal property than the PPC, so that the chlorinated polypropylene carbonate is more suitable for being applied to food preservative films. Meanwhile, the competitive power of the polymer on the cost performance and the traditional plastic is effectively improved by using the lower cost of the C-PPC compared with other biodegradable plastics.

And, polypropylene carbonate (PPC) belongs to the polyester group, has a very strong hydrophobic surface, and requires modification of its surface to increase its hydrophilicity if it is to be applied to medical materials or food packaging fields. However, the PPC is not modified by a melt blending method because the PPC has low glass transition temperature and poor thermal stability compared with the conventional polymer and is partially decomposed during the thermal processing process to influence the performance of the PPC; the blending modification of the solvent needs to use an organic solvent, which goes against the original purpose of using PPC as a green environment-friendly polymer.

The surface modification of the existing polymer material is mainly chemical modification, and the main methods are as follows: (1) a plasma treatment method; (2) surface grafting method; (3) radiation treatment cross-linking method; (4) atomic force microprobe oscillation method, and the like. In consideration of avoiding the use of organic solvents and other harmful substances, the invention selects chlorinated polypropylene carbonate (C-PPC) as a raw material, increases the bactericidal property of the PPC by introducing chloride ions, and is beneficial to the application of the PPC in the fields of medical use, food packaging and the like; secondly, selecting plasma to treat the surface of the C-PPC, grafting MA containing-COOH and SBMA to the surface of the C-PPC by using an ultraviolet grafting method, and then carrying out electrostatic interaction to lysozyme, antibacterial peptide and the like with positive charges.

Finally, in order to enable the polymer to have good antibacterial property, the invention adopts an active antibacterial packaging method, and introduces active factors with positive charges on the surface into the surface of the polymer C-PPC-g-P (SBMA-co-MA) with negative charges through electrostatic action, thereby obtaining the composite polymer with broad-spectrum antibacterial property.

Preferably, in the step i, the method for preparing the C-PPC film specifically comprises:

i-1, preparing a C-PPC film from a C-PPC solution with the mass concentration of 8-13% by a film forming process;

and I-2, placing the C-PPC membrane obtained in the step I-1 in a vacuum oven to dry at room temperature to constant weight.

More preferably, the film forming process includes spin coating and electrospinning.

Exemplarily, one method for preparing the C-PPC film by the spin coating method is as follows: preparing a C-PPC aqueous solution with the concentration of 8-13%, taking 100-200 mu L of the aqueous solution by using a liquid-transferring gun, dropwise adding the aqueous solution on a spin coater, setting the rotation speed to 8000-10000 rpm, and treating for 30s to obtain the C-PPC film.

Exemplarily, one method for preparing the C-PPC film by the electrospinning method is as follows: preparing a C-PPC solution with the concentration of 8-13%, setting the inner diameter of a spinning needle to be 0.33-0.80 mm, the spinning voltage to be 4-15 kV, the injection speed to be 0.06-0.3 mm/min, the rotating speed of a receiving roller to be 20-60 rpm, the receiving distance to be 5-15 cm, the spinning temperature to be 20-30 ℃, and the humidity to be 30-60%, and spinning to obtain the C-PPC membrane.

Preferably, in the step II, the preparation method of C-PPC-g-P (SBMA-co-MA) specifically comprises the following steps:

II-1, putting the constant-weight C-PPC film obtained in the step I into plasma, setting the power to be 100W, and treating for 60-90 s;

II-2, preparing an aqueous solution of MA-SBMA, wherein MA: SBMA: the weight ratio of water is 1:1: 4;

II-3, dropwise adding the solution prepared in the step II-2 on the C-PPC membrane treated by the plasma in the step II-1, and carrying out ultraviolet grafting treatment, wherein the ultraviolet wavelength is set to be 365nm, the power is set to be 300W, and the treatment time is set to be 5-30 min, so that C-PPC-g-P (SBMA-co-MA) is obtained.

Preferably, the active factor in step III comprises at least one or two of Lysozyme (LYZ) and antimicrobial peptide (C).

Among them, Lysozyme (LYZ) is an excellent natural antibacterial protein, which is commercially available at low cost, and is a glycoside hydrolase that can specifically hydrolyze peptidoglycan, a major component in the cell wall of prokaryotic bacteria. It can directly act with virus protein with negative charge, and form salt with DNA, RNA and apoprotein to inactivate virus, and directly hydrolyze gram-positive bacteria; it can also hydrolyze gram-negative bacteria such as Escherichia coli in the presence of secretory immunoglobulin A and complement.

The antibacterial peptide (Cecropin) is a kind of small molecular peptide, which has the characteristics of wide distribution, small molecular weight, good thermal stability, broad-spectrum antibacterial property and the like, and has high-efficiency broad-spectrum killing effect on gram-negative and gram-positive bacteria. At least 113 different bacteria have been reported to be killed by antibacterial peptide at home and abroad, and some antibacterial peptides have strong killing effect on partial bacteria, fungi, protozoa and viruses. It is believed that the antimicrobial peptides act on the cell membrane to form ion channels across the membrane, disrupting the integrity of the membrane, causing leakage of the cell contents, and thereby killing the cells.

More preferably, in the step iii, the preparation method of the antibacterial degradable polymer specifically comprises:

III-1, preparing a single-activity factor/PBS solution with the concentration of 0.1-2 mg/mL;

III-2, placing the C-PPC-g-P (SBMA-co-MA) prepared in the step II in the active factor/PBS solution prepared in the step III-1, keeping the temperature at 37 +/-0.5 ℃ for 30-150 min, and washing for 3 times by using a PBS buffer solution to obtain the antibacterial degradable polymer with the single active factor;

III-3, repeating the steps III-1 to III-2 to obtain the antibacterial degradable polymer with multiple active factors.

Notably, the pH of the PBS buffer was 7.4.

Compared with the prior art, the preparation method provided by the invention selects the completely biodegradable high molecular material C-PPC as the matrix material, avoids the use of plasticizers and organic solvents, increases the active antibacterial property of the degradable polymer by introducing active factors such as lysozyme, antibacterial peptide and the like, is simple to operate, is green and environment-friendly, and has good application prospect.

The invention also aims to provide the antibacterial degradable polymer obtained by the preparation method of the antibacterial degradable polymer.

The antibacterial degradable polymer comprises a C-PPC-g-P (SBMA-co-MA) -co-LYZ composite polymer, a C-PPC-g-P (SBMA-co-MA) -co-C composite polymer or a C-PPC-g-P (SBMA-co-MA) -co-LYZ/C composite polymer.

It is still another object of the present invention to provide the use of said antibacterial degradable polymer in the production of films or film products.

In some application scenarios, the film or film article comprises a food preservative film.

According to the technical scheme, compared with the prior art, the invention provides the antibacterial degradable polymer and the preparation method and application thereof, the C-PPC membrane is prepared by adopting a spin coating or electrostatic spinning method, the P (SBMA-co-MA) is grafted to the surface of the C-PPC-g-P (SBMA-co-MA) by utilizing an ultraviolet branch knot technology to realize the introduction of carboxyl, and finally one or two active factors comprising antibacterial peptide (C) and Lysozyme (LYZ) are combined to the surface of the C-PPC-g-P (SBMA-co-MA) -co-LYZ, C-PPC-g-P (SBMA-co-MA) -co-C and C-PPC-g-P (SBMA-co-MA) -co-LYZ- And C, performing treatment. In addition, the antibacterial degradable polymer avoids the use of a plasticizer in the preparation process, so that the antibacterial degradable polymer is very suitable for food packaging, especially food preservative films.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic diagram of a preparation process of the antibacterial degradable polymer C-PPC-g-P (SBMA-co-MA) -co-C composite polymer of the present invention.

FIG. 2 shows XPS scan energy spectra of C-PPC film, C-PPC-g-P (SBMA-co-MA) film and C-PPC-g-P (SBMA-co-MA) -co-LYZ film provided in Experimental example 1 of the present invention.

FIG. 3 is a schematic diagram of the bacteriostatic rate of the PPC membrane, C-PPC-g-P (SBMA-co-MA) membrane and C-PPC-g-P (SBMA-co-MA) -co-LYZ membrane provided in Experimental example 2 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention discloses an antibacterial degradable polymer and a preparation method and application thereof, the polymer material prepared by the invention is biodegradable, has good antibacterial property, avoids the use of organic solvents and harmful substances, overcomes the defects in the prior art, and is particularly suitable for application in the field of food packaging.

A preparation method of an antibacterial degradable polymer specifically comprises the following steps:

preparing a chlorinated polypropylene carbonate C-PPC solution into a C-PPC film by a film forming process;

II, carrying out plasma treatment on the C-PPC membrane obtained in the step I, and carrying out ultraviolet grafting reaction on the C-PPC membrane subjected to the plasma treatment and methacrylic acid MA and methacrylic acid betaine (SBMA) molecules to obtain C-PPC-g-P (SBMA-co-MA);

and III, combining the C-PPC-g-P (SBMA-co-MA) obtained in the step II with an active factor to finally obtain the antibacterial degradable polymer.

Preferably, in the step i, the method for preparing the C-PPC film specifically comprises:

i-1, preparing a C-PPC film from a C-PPC solution with the mass concentration of 8-13% by a film forming process;

and I-2, placing the C-PPC membrane obtained in the step I-1 in a vacuum oven to dry at room temperature to constant weight.

Preferably, in the step i-1, the film forming process includes a spin coating method or an electrospinning method.

Preferably, in the step II, the preparation method of C-PPC-g-P (SBMA-co-MA) specifically comprises the following steps:

II-1, putting the constant-weight C-PPC film obtained in the step I into plasma, setting the power to be 100W, and treating for 60-90 s;

II-2, preparing an aqueous solution of MA-SBMA, wherein MA: SBMA: the weight ratio of water is 1:1: 4;

II-3, dropwise adding the solution prepared in the step II-2 on the C-PPC membrane treated by the plasma in the step II-1, and carrying out ultraviolet grafting treatment, wherein the ultraviolet wavelength is set to be 365nm, the power is set to be 300W, and the treatment time is set to be 5-30 min, so that C-PPC-g-P (SBMA-co-MA) is obtained.

Preferably, the active factor in step III comprises at least one or two of lysozyme LYZ and antimicrobial peptide C.

Preferably, in the step iii, the preparation method of the antibacterial degradable polymer specifically comprises:

III-1, preparing a single-activity factor/PBS solution with the concentration of 0.1-2 mg/mL;

III-2, placing the C-PPC-g-P (SBMA-co-MA) prepared in the step II in the active factor/PBS solution prepared in the step III-1, keeping the temperature at 37 +/-0.5 ℃ for 30-150 min, and washing for 3 times by using a PBS buffer solution to obtain the antibacterial degradable polymer with the single active factor;

III-3, repeating the steps III-1 to III-2 to obtain the antibacterial degradable polymer with multiple active factors.

The invention also claims an antibacterial degradable polymer prepared by the preparation method, and the antibacterial degradable polymer comprises a C-PPC-g-P (SBMA-co-MA) -co-LYZ composite polymer, a C-PPC-g-P (SBMA-co-MA) -co-C composite polymer or a C-PPC-g-P (SBMA-co-MA) -co-LYZ/C composite polymer.

Meanwhile, the invention claims the application of the antibacterial degradable polymer in the production of films or film products.

Preferably, the film or film product is a food preservative film.

The present invention will be further specifically illustrated by the following examples for better understanding, but the present invention is not to be construed as being limited thereto, and certain insubstantial modifications and adaptations of the invention by those skilled in the art based on the foregoing disclosure are intended to be included within the scope of the invention.

When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any value therebetween can be selected unless the invention otherwise indicated. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The raw materials used in the present invention are all common commercial products unless otherwise specified.