CN111501342A - A kind of antibacterial polylactic acid fabric and preparation method thereof - Google Patents

Abstract

The invention provides an antibacterial polylactic acid fabric and a preparation method thereof, wherein the antibacterial polylactic acid fabric is prepared from a polylactic acid fabric, N-vinyl pyrrolidone (NVP) and a silver-containing compound, specifically, the polyvinyl pyrrolidone (PVP) is grafted on the polylactic acid fabric through radiation grafting, and meanwhile, silver nanoparticles are loaded on the surface of the polylactic acid fabric through radiation reduction, so that the antibacterial polylactic acid fabric is obtained. The antibacterial polylactic acid fabric has antibacterial and hydrophilic functions, can be applied to the field of textile fabrics, and has good skin-friendly property and moisture absorption.

Description

A kind of antibacterial polylactic acid fabric and preparation method thereof

technical field

The invention relates to the field of polylactic acid materials, in particular to an antibacterial polylactic acid fabric and a preparation method thereof.

Background technique

Polylactic acid (PLA) is a polymer synthesized from lactic acid. It is non-toxic, non-irritating and good biocompatibility. It is a completely biodegradable aliphatic polyester. The fabricated fabric is comfortable to wear, has good elasticity and good drapability, and can be widely used in the field of textile fabrics.

However, the hydrophilic and antibacterial properties of PLA fabrics limit the application range of PLA fabrics.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned problems, the present inventors have carried out keen research to develop an antibacterial polylactic acid fabric and a preparation method thereof. The antibacterial polylactic acid fabric is prepared from polylactic acid fabric, NVP and a silver-containing compound. Grafting PVP on the polylactic acid fabric, and loading silver nanoparticles on the surface of the polylactic acid fabric by radiation reduction, thereby obtaining an antibacterial polylactic acid fabric. The antibacterial polylactic acid fabric of the present invention has both antibacterial and hydrophilic functions, can be applied to the field of textile fabrics, and has good skin affinity and hygroscopicity, thereby completing the present invention.

The object of the present invention is to provide an antibacterial polylactic acid fabric, the antibacterial polylactic acid fabric is obtained by irradiation treatment of polylactic acid fabric, NVP and a silver-containing compound, preferably, the water droplet soaking time of the antibacterial polylactic acid fabric is less than 50s, the antibacterial rate is greater than 90%.

The antibacterial polylactic acid material is prepared by a method comprising the following steps:

Step 1. Prepare a solution containing NVP and a silver-containing compound;

Step 2, soak the polylactic acid fabric in the solution obtained in step 1, and carry out irradiation treatment;

Step 3, post-processing the irradiated polylactic acid fabric obtained in step 2 to obtain the antibacterial polylactic acid fabric.

The silver-containing compound is silver nitrate, and the solvent in the solution is selected from one or more of water, methanol, acetone and ethanol, preferably methanol, such as anhydrous methanol.

In step 2, the conditions of the irradiation treatment: the irradiation source is a cobalt source, and the irradiation dose rate is 20-80 Gy/min, preferably 30-60 Gy/min.

The invention provides a preparation method of an antibacterial polylactic acid fabric, the method comprising:

Step 1. Prepare a solution containing NVP and a silver-containing compound;

Step 2, soak the polylactic acid fabric in the solution obtained in step 1, and carry out irradiation treatment;

Step 3, post-processing the irradiated polylactic acid fabric obtained in step 2 to obtain the antibacterial polylactic acid fabric.

In step 1, the preparation of a solution containing NVP and a silver-containing compound includes: adding NVP and a silver-containing compound into a solvent, and mixing to obtain the solution,

In the solution, the concentration of NVP is 0.2-4 mol/L, and the concentration of silver ions is 0.0001-0.05 mol/L.

In the solution, the concentration of NVP is 0.6-3 mol/L, preferably the concentration of silver ions is 0.0002-0.002 mol/L.

In step 2, the soaking time of the polylactic acid fabric in the solution obtained in step 1 is 10-50 minutes, preferably 15-40 minutes, for example, 20-30 minutes.

The post-treatment includes: washing and drying the irradiated polylactic acid fabric, wherein the washing is washing with deionized water for 20-40 hours, and the drying is drying at 40-60° C. to a constant weight.

The present invention provides the antibacterial polylactic acid fabric obtained by the above method.

The beneficial effects that the present invention has are:

(1) In the present invention, by grafting PVP on the polylactic acid fabric and loading silver nanoparticles, the PVP and Ag are firmly combined with the polylactic acid fabric, thereby obtaining a polylactic acid fabric with excellent hydrophilicity and antibacterial properties. For example, the obtained The antibacterial performance of the antibacterial polylactic acid fabric is greater than 90%, and can even reach more than 99%, and the water droplet soaking time is less than 50s, preferably less than 20s, or even less than 10s, such as 4.1s;

(2) The antibacterial polylactic acid fabric of the present invention makes the NVP monomer evenly grafted to the polylactic acid fabric and supports silver nanoparticles by the radiation method, and the obtained PVP and silver nanoparticles are uniformly distributed on the surface of the antibacterial polylactic acid fabric, and the graft ratio of PVP Can be adjusted by radiation dose and NVP monomer concentration to meet different needs;

(3) The method for preparing the antibacterial polylactic acid fabric of the present invention directly modifies the base of the polylactic acid fabric, and the process method is simple, and the obtained antibacterial polylactic acid fabric has good skin affinity and can be widely used in the field of textile fabrics.

Description of drawings

Fig. 1 shows the test result of the grafting ratio gained in Experimental Example 1 of the present invention;

Fig. 2 shows the infrared spectrogram obtained in Experimental Example 2 of the present invention;

Fig. 3 shows the SEM image obtained in Experimental Example 3 of the present invention;

Fig. 4 shows the EDS diagram obtained in Example 18 of the present invention;

Fig. 5 shows the XPS spectrogram of Experimental Example 4 of the present invention;

Fig. 6 shows the TGA test result obtained in Experimental Example 5 of the present invention;

Fig. 7 shows the bacterial solid figure of the obtained antibacterial performance test of Experimental Example 7 of the present invention;

FIG. 8 shows the test results of washing fastness obtained in Experimental Example 8 of the present invention.

Detailed ways

The present invention will be further described in detail below through the accompanying drawings and preferred embodiments. The features and advantages of the present invention will become more apparent from these descriptions.

The invention provides an antibacterial polylactic acid fabric. The antibacterial polylactic acid fabric is obtained by irradiating a polylactic acid fabric, NVP (N-vinylpyrrolidone) and a silver-containing compound.

In the present invention, under irradiation conditions, the polylactic acid fabric and the NVP monomer undergo a co-radiation grafting reaction to obtain a graft copolymer, which can be recorded as PLA-g-PVP. By grafting the NVP monomer to the PLA molecule On the chain, it is beneficial to improve the surface hydrophilicity of the PLA fabric. At the same time, the silver-containing compound is reduced to obtain Ag nanoparticles, which are loaded on the PLA fabric to obtain an antibacterial PLA fabric, which can be recorded as PLA-g-PVP -g-Ag, realizes the chemical bonding between Ag nanoparticles and PLA, thus endows the PLA fabric with good hydrophilicity and antibacterial properties.

According to the present invention, the water droplet soaking time (or the water droplet spreading time) of the provided antibacterial polylactic acid fiber is less than 50s, and can even reach below 10s, for example, 4.1s.

In the present invention, the C1s spectrum is the photoelectron energy spectrum detected after the electrons on the 1s orbital of the carbon atom are excited, and the abscissa of the XPS spectrum is the binding energy (the binding energy of the electron and the nucleus), that is, the electron is stable on its orbit The energy is related to the structure and valence state of the atom, so the chemical bond state of the C atom can be obtained according to the change spectrum of the electron binding energy on the C1s orbital. The O1s spectrum is the 1s orbital spectrum of the oxygen atom, which is similar in principle to the C1s spectrum. By analyzing the O1s spectrum, we can see the different bonding states of the O atoms; in the Ag3d spectrum, Ag3d _3/2 and Ag3d _5/2 are Ag The characteristic peaks of different spin electrons of atomic 3d orbitals prove the existence of Ag atoms.

According to the present invention, the XPS spectrum of the antibacterial polylactic acid fabric includes C1s, O1s and Ag 3d spectrum.

According to the present invention, in the obtained antibacterial polylactic acid fabric, the Ag 3d spectrum includes characteristic peaks with binding energies at 368.0 and 374.0 eV, and the characteristic peaks correspond to 3d _5/2 and 3d _3/2 of Ag atoms at 368.8 and 374.8 eV. The characteristic peaks correspond to Ag ⁺ 3d _5/2 and 3d _3/2 , respectively.

In the present invention, Ag and the surface of the polylactic acid material are chemically bonded, and the characteristic peaks of Ag3d _3/2 and Ag3d _5/2 and the characteristic peaks of Ag ⁺ 3d _3/2 and Ag ⁺ 3d _5/2 indicate that the polylactic acid antibacterial material has both Ag ⁰ and Ag ⁺ are distributed. Part of the reduced Ag element is encapsulated in the polymer during the polymerization of the PVP chain and exists stably, while part of the Ag ⁺ is bound to the surface of the PLA material through coordination bonds, making the Ag and PLA material. The combination between them is stronger, thereby enhancing the washability and antibacterial properties of the obtained polylactic acid antibacterial material.

According to the present invention, in the obtained antibacterial polylactic acid fabric, in the C1s spectrum, there are characteristic peaks whose binding energy is located at 284.2-285.4 eV, preferably at 284.8 eV, the binding energy corresponds to the carbon chain main peak, and also includes a characteristic peak at 288.6-289.8 eV , preferably the characteristic peak at 289.2 eV, which corresponds to the C=O double bond in the sample, and also includes the characteristic peak at 286.8-287.6 eV, preferably at 287.2 eV, the characteristic peak corresponds to the C-O bond, and also includes the characteristic peak at 287.2 eV. 285.5～286.5eV, preferably a new characteristic peak at 286.0eV, which corresponds to the C(=O)-N bond in the pyrrolidone ring, which can prove that the surface of PLA fabric is successfully grafted with PVP long chain.

According to the present invention, the O1s spectrum of the obtained antibacterial PLA fabric includes a characteristic peak at 533.0-534.6 eV, preferably at 533.8 eV, the characteristic peak corresponds to C=O, and also includes at 531.5-532.6 eV, preferably at 532.1 eV The characteristic peak of , which corresponds to C-O. It also includes a peak at a lower binding energy of 531.0-532.2 eV, preferably at 531.6 eV, which is a silver-oxygen coordination peak, indicating that in this system, Ag and O atoms are connected by coordination bonds.

According to the present invention, the N1s spectrum of the antibacterial PLA fabric includes a peak at 394.0-395.0, preferably at 394.6 eV, which is a silver-nitrogen coordination peak, which can indicate that Ag particles and N atoms in the system Coordination is also present.

The inventors speculate that in the antibacterial polylactic acid fabric, Ag nanoparticles form coordination bonds with O and N in the PVP molecule, and the PVP molecule plays the role of connecting the Ag nanoparticles and the polylactic acid fabric.

According to a preferred embodiment of the present invention, the silver-containing compound is silver nitrate.

The invention provides a preparation method of an antibacterial polylactic acid fabric, which comprises the following steps:

Step 1. Prepare a solution containing NVP and a silver-containing compound.

According to the present invention, in step 1, preparing a solution containing NVP and a silver-containing compound includes: adding NVP and a silver-containing compound into a solvent, and mixing uniformly to obtain the solution.

According to a preferred embodiment of the present invention, preparing a solution containing NVP and a silver-containing compound includes: adding NVP to a solvent, mixing uniformly, then adding a silver-containing compound, and mixing uniformly to obtain the solution.

According to a preferred embodiment of the present invention, the solvent is selected from one or more of water, methanol, propanol, and ethanol, preferably methanol, such as anhydrous methanol.

According to a preferred embodiment of the present invention, in the solution, the concentration of NVP is 0.5-4 mol/L, the concentration of silver ions is 0.0001-0.05 mol/L, preferably, the concentration of NVP is 0.6-3 mol/L, the concentration of silver The concentration of ions is 0.0002-0.002mol/L, more preferably, the concentration of NVP is 1-2mol/L, the concentration of silver ions is 0.0002-0.001mol/L, for example, the concentration of NVP is 1.56mol/L, the concentration of silver ions The concentration of 0.0005mol/L.

In the present invention, the grafting rate of NVP increases with the increase of NVP monomer concentration, but too high grafting rate will easily lead to the adhesion of fibers in the PLA fabric, making the fibers in the PLA fabric rough and damaged . At the same time, if the loading of silver particles is too high, the hydrophilicity of the PLA fabric will be seriously affected, and if the loading amount is too small, the antibacterial properties of the PLA fabric cannot be guaranteed. Therefore, it is necessary to comprehensively consider the concentration of NVP monomers and the concentration of silver particles.

In the present invention, the reduction reaction activity of the silver compound is relatively high, and the antibacterial polylactic acid fabric with an antibacterial rate greater than 90% or even greater than 99% can be obtained at a lower concentration of silver ions. For example, when the concentration of silver ions is 0.0005mol /L, the antibacterial rate of the obtained antibacterial polylactic acid fabric can reach more than 99%.

In the present invention, under irradiation conditions, vinylpyrrolidone (NVP) and polylactic acid fabric undergo a co-radiation grafting reaction, so that NVP is grafted and copolymerized on the surface of polylactic acid fabric to form PVP (polyvinylpyrrolidone) long chain grafts on the polylactic acid fabric. On the lactic acid molecular chain, the graft copolymer PVP grafted polylactic acid fabric, that is, PLA-g-PVP, is obtained. At the same time, Ag ions are reduced to form coordination bonds with polylactic acid molecules or PVP, so as to be firm with polylactic acid fabric. combined with excellent hydrophilicity and antibacterial properties at the same time.

Step 2, soak the polylactic acid fabric in the solution obtained in step 1, and perform irradiation treatment.

According to the present invention, the polylactic acid fabric needs to be washed with ethanol to wash the surface oil and dust before soaking, and the washed polylactic acid fabric is dried to constant weight at room temperature.

According to the present invention, in step 2, the polylactic acid fabric is soaked in the solution obtained in step 1, and then placed in an irradiation tube, nitrogen is introduced to remove oxygen, and the irradiation tube is placed in a cobalt source room for irradiation after sealing.

According to the present invention, in step 2, the soaking time of the polylactic acid fabric in the solution is 10-50 minutes, preferably 15-40 minutes, more preferably 20-30 minutes, such as 20 minutes.

According to the present invention, the polylactic acid fabric can be completely immersed in the NVP and the silver-containing compound solution, and after the polylactic acid fabric is completely soaked, it is put into the irradiation tube together.

According to the present invention, nitrogen is introduced to remove oxygen, and in some cases, nitrogen is introduced into the irradiation tube for 10-40 min, preferably 30 min, and then the irradiation tube is sealed and irradiated in a cobalt source chamber.

According to the present invention, the conditions of irradiation treatment: the irradiation dose rate is 20-80 Gy/min, preferably 30-60 Gy/min; the irradiation dose is 2-60 kGy, preferably 10-40 kGy, more preferably 20-35 kGy, For example 25kGy.

In the present invention, when the irradiation dose is low, the grafting rate of the obtained PVP-PLA fabric is low, but when the irradiation dose is too high, the grafting rate will decrease, because in the reaction system, there are grafting at the same time Reaction and degradation reaction, under higher irradiation dose, the degree of degradation reaction of the PVP polymer chain grafted on the surface of PLA fabric is greater, and the scission of the grafted molecular chain leads to a decrease in the grafting rate of the obtained antibacterial polylactic acid fabric, which affects the antibacterial and antibacterial properties. Hydrophilicity of PLA fabrics.

In the present invention, irradiation treatment is performed under a nitrogen atmosphere, free radicals are generated on the polylactic acid molecules of the polylactic acid fabric, and the NVP monomers are grafted on the polylactic acid molecules to initiate the graft polymerization, that is, the co-radiation grafting reaction, while at the same time containing The silver compound undergoes a radiation reduction reaction to obtain silver particles, and the silver forms a coordination bond with O on the molecular chain, thereby realizing the graft modification of polylactic acid, and obtaining an antibacterial polylactic acid fabric.

According to a preferred embodiment of the present invention, when the loading amount of Ag nanoparticles is more than 320 mg/kg, the antibacterial rate against Staphylococcus aureus is more than 99%, the antibacterial activity value can reach more than 5.5, and the antibacterial performance is excellent.

The inventors found that after grafting PVP, the heat resistance of the polylactic acid fabric decreased, and the decomposition temperature decreased. After the polylactic acid fabric was loaded with silver nanoparticles, the influence of the polylactic acid fabric by PVP was weakened, and the stability of the fabric was comparable to that of the unmodified fabric. .

Step 3, post-processing the irradiated polylactic acid fabric obtained in step 2 to obtain the antibacterial polylactic acid fabric.

According to the present invention, in step 3, the post-treatment of the irradiated polylactic acid fabric includes: washing and drying the irradiated polylactic acid fabric. The drying is drying to constant weight at 45-75°C, preferably, washing with deionized water for 30 hours, and then drying at 65°C to constant weight to obtain antibacterial polylactic acid fabric.

In the present invention, by grafting PVP on the surface of the polylactic acid fabric, the hydrophilicity of the polylactic acid fabric is improved, and the silver and the PVP or the surface of the polylactic acid fabric are coordinated to form a coordination bond, so that the silver can interact with the chemical bond through the action of the chemical bond. The combination of polylactic acid fabrics makes the antibacterial properties of polylactic acid fabrics more stable, increases the washability of polylactic acid fabrics, and silver nanoparticles can improve the thermal stability of antibacterial polylactic acid fabrics, making polylactic acid fabrics less prone to degradation and thermal decomposition. .

According to the present invention, the antibacterial PLA fabric has an antibacterial rate of more than 90%, or even more than 99%, an antibacterial activity value of more than 1.5, or even more than 5.5, and a water droplet soaking time of less than 50s, or even less than 20s, such as 4.1s.

The antibacterial polylactic acid fabric obtained by the invention has good washing resistance, and the silver content does not decrease significantly after long-time rinsing, which shows that the silver nanoparticle loading on the antibacterial lactic acid fabric is stable and the washing resistance is good.

The antibacterial polylactic acid fabric obtained by the invention has excellent antibacterial property and also retains good hydrophilicity. When applied to textile fabrics, it has good skin affinity, and the hydrophilicity can also reduce the static electricity of the polylactic acid fabric. role, has better application significance.

Example

In the embodiment, the polylactic acid fabric is a polylactic acid fabric, purchased from Puyang Yurun New Material Co., Ltd.

In the following examples, the polylactic acid fabrics were pretreated as follows: the polylactic acid fabrics were cut to a size of 15×15 cm ² , and the fabric surface oil and dust were washed with absolute ethanol, and then dried at room temperature to constant weight back up.

Example 1

Add NVP monomer to 100ml of anhydrous methanol, stir and mix evenly to obtain a solution, so that the concentration of NVP monomer in the solution is 0.78mol/L;

Soak the polylactic acid fabric in the solution for 30min, then transfer the polylactic acid fabric and the solution to the irradiation tube together, pass nitrogen into the irradiation tube for 30min to remove oxygen, then seal the irradiation tube and put it into the cobalt source chamber Carry out irradiation, the irradiation dose is 10kGy, and the irradiation dose rate is 50Gy/min;

After the irradiation, the polylactic acid fabric was transferred from the irradiation tube to excess deionized water, stirred and washed for 30 hours, and then dried in a blast oven at 60 °C to constant weight; the PVP grafted polylactic acid fabric was obtained, denoted as PLA-g-PVP.

Example 2

The process of Example 1 was repeated, except that the concentration of NVP monomer in the solution was 0.96 mol/L, and other processes were the same as those of the Example.

Example 3

The process of Example 1 was repeated, except that the NVP monomer concentration in the solution was 1.23 mol/L, and the other processes were the same as those of the Example.

Example 4

The process of Example 1 was repeated, except that the NVP monomer concentration in the solution was 1.56 mol/L, and the other processes were the same as those of the Example.

Example 5

The process of Example 1 was repeated, except that the concentration of NVP monomer in the solution was 2.34 mol/L, and other processes were the same as those of Example 1.

Example 6

The process of Example 1 was repeated, except that the concentration of NVP monomer in the solution was 3.12 mol/L, and other processes were the same as those of Example 1.

Example 7

The process of Example 4 was repeated, except that the irradiation dose was 2 kGy, and other processes were the same as those of Example 4.

Example 8

The process of Example 4 was repeated, except that the irradiation dose was 5 kGy, and other processes were the same as those of Example 4.

Example 9

The process of Example 4 was repeated, except that the irradiation dose was 15 kGy, and other processes were the same as those of Example 1.

Example 10

The process of Example 4 was repeated, except that the irradiation dose was 20 kGy, and other processes were the same as those of Example 4.

Example 11

The process of Example 4 was repeated, except that the irradiation dose was 40 kGy, and the other processes were the same as those of Example 4.

Example 12

The process of Example 4 was repeated, except that the irradiation dose was 60 kGy, and other processes were the same as those of Example 4.

Example 13

Add NVP monomer and silver nitrate to 100ml of anhydrous methanol, stir and mix evenly to obtain a solution, so that the concentration of NVP monomer in the solution is 1.56mol/L, and the concentration of silver nitrate is 0.0002mol/L;

Soak the polylactic acid fabric in the solution for 30min, then transfer the polylactic acid fabric and the solution to the irradiation tube together, pass nitrogen into the irradiation tube for 30min to remove oxygen, then seal the irradiation tube and put it into the cobalt source chamber Carry out irradiation, the irradiation dose is 10kGy, and the irradiation dose rate is 50Gy/min;

After the irradiation, the PLA fabric was transferred from the irradiation tube to excess deionized water, stirred and washed for 30 hours, and then dried in a blast oven at 60°C to constant weight; the antibacterial PLA fabric was obtained, which was recorded as PLA- g-PVP-g-Ag.

The ICP test was carried out on the obtained antibacterial polylactic acid fabric, and the silver loading was measured to be 170 mg/kg.

Example 14

Add NVP monomer and silver nitrate to 100ml of anhydrous methanol, stir and mix evenly to obtain a solution, so that the concentration of NVP monomer in the solution is 1.56mol/L, and the concentration of silver nitrate is 0.0005mol/L;

Soak the polylactic acid fabric in the solution for 30min, then transfer the polylactic acid fabric and the solution to the irradiation tube together, pass nitrogen into the irradiation tube for 30min to remove oxygen, then seal the irradiation tube and put it into the cobalt source chamber Carry out irradiation, the irradiation dose is 10kGy, and the irradiation dose rate is 50Gy/min;

After the irradiation, the PLA fabric was transferred from the irradiation tube to excess deionized water, stirred and washed for 30 hours, and then dried in a blast oven at 65°C to constant weight; the antibacterial PLA fabric was obtained, denoted as PLA- g-PVP-g-Ag.

The ICP test was carried out on the obtained antibacterial polylactic acid fabric, and the silver loading was measured to be 320 mg/kg.

Example 15

Add NVP monomer and silver nitrate to 100ml of anhydrous methanol, stir and mix to obtain a solution, so that the concentration of NVP monomer in the solution is 1.56mol/L, and the concentration of silver nitrate is 0.002mol/L;

Soak the polylactic acid fabric in the solution for 30min, then transfer the polylactic acid fabric and the solution to the irradiation tube together, pass nitrogen into the irradiation tube for 30min to remove oxygen, then seal the irradiation tube and put it into the cobalt source chamber Carry out irradiation, the irradiation dose is 10kGy, and the irradiation dose rate is 50Gy/min;

After the irradiation, the PLA fabric was transferred from the irradiation tube to excess deionized water, stirred and washed for 30 hours, and then dried in a blast oven at 60°C to constant weight; the antibacterial PLA fabric was obtained, which was recorded as PLA- g-PVP-g-Ag.

The ICP test was carried out on the obtained antibacterial polylactic acid fabric, and the silver loading was measured to be 1100 mg/kg.

Example 16

Add NVP monomer and silver nitrate to 100ml of anhydrous methanol, stir and mix evenly to obtain a solution, so that the concentration of NVP monomer in the solution is 1.56mol/L, and the concentration of silver nitrate is 0.005mol/L;

Soak the polylactic acid fabric in the solution for 30min, then transfer the polylactic acid fabric and the solution to the irradiation tube together, pass nitrogen into the irradiation tube for 30min to remove oxygen, then seal the irradiation tube and put it into the cobalt source chamber Carry out irradiation, the irradiation dose is 10kGy, and the irradiation dose rate is 50Gy/min;

After the irradiation, the PLA fabric was transferred from the irradiation tube to excess deionized water, stirred and washed for 30 hours, and then dried in a blast oven at 60°C to constant weight; the antibacterial PLA fabric was obtained, which was recorded as PLA- g-PVP-g-Ag.

The ICP test was carried out on the obtained antibacterial polylactic acid fabric, and the silver loading was measured to be 1350 mg/kg.

Example 17

Add NVP monomer and silver nitrate to 100ml of anhydrous methanol, stir and mix evenly to obtain a solution, so that the concentration of NVP monomer in the solution is 1.56mol/L, and the concentration of silver nitrate is 0.01mol/L;

Soak the polylactic acid fabric in the solution for 30min, then transfer the polylactic acid fabric and the solution to the irradiation tube together, pass nitrogen into the irradiation tube for 30min to remove oxygen, then seal the irradiation tube and put it into the cobalt source chamber Irradiate, the irradiation dose is 10kGy, and the irradiation dose rate is 60Gy/min;

After the irradiation, the PLA fabric was transferred from the irradiation tube to excess deionized water, stirred and washed for 30 hours, and then dried in a blast oven at 60°C to constant weight; the antibacterial PLA fabric was obtained, which was recorded as PLA- g-PVP-g-Ag.

The ICP test was carried out on the obtained antibacterial polylactic acid fabric, and the silver loading was measured to be 1780 mg/kg.

Example 18

Add NVP monomer and silver nitrate to 100ml of anhydrous methanol, stir and mix to obtain a solution, so that the concentration of NVP monomer in the solution is 1.56mol/L, and the concentration of silver nitrate is 0.03mol/L;

Soak the polylactic acid fabric in the solution for 30min, then transfer the polylactic acid fabric and the solution to the irradiation tube together, pass nitrogen into the irradiation tube for 30min to remove oxygen, then seal the irradiation tube and put it into the cobalt source chamber Carry out irradiation, the irradiation dose is 10kGy, and the irradiation dose rate is 50Gy/min;

After the irradiation, the PLA fabric was transferred from the irradiation tube to excess deionized water, stirred and washed for 30 hours, and then dried in a blast oven at 60°C to constant weight; the antibacterial PLA fabric was obtained, which was recorded as PLA- g-PVP-g-Ag.

The ICP test was carried out on the obtained antibacterial polylactic acid fabric, and the silver loading was measured to be 1900 mg/kg.

The obtained antibacterial fabric was tested by EDX, and the test results are shown in Figure 4 and Table 2. In Figure 4, (1) is the distribution map of C element, (2) is the distribution map of O element, and (3) is the distribution map of N element. Distribution map, (4) is the distribution map of Ag element.

It can be seen from Figure 4 that C, O, N, and Ag are evenly distributed on the surface of the obtained antibacterial PLA fabric, indicating that the PVP and Ag nanoparticles are relatively uniformly distributed on the surface of the antibacterial PLA fabric.

Table 1 shows the content of each element on the surface of the antibacterial polylactic acid fabric.

Table 1

Example 19

The process of Example 18 was repeated, except that the concentration of silver nitrate was 0.0007 mol/L, and other processes were the same as those of Example 18 to obtain an antibacterial polylactic acid fabric.

Comparative ratio

Comparative Example 1

The polylactic acid fabric was cut into a size of 10*10cm, washed, and dried for use as a sample of Comparative Example 1.

Comparative Example 2

Cut the polylactic acid fabric into a size of 10cm*10cm, stir and wash in deionized water and ethanol successively, and dry it for later use;

Weigh 80ml of ethanol and 20ml of water, and mix the ethanol and water evenly to obtain a solvent, add 20ml of acrylic acid monomer to the solvent to make the acrylic acid monomer concentration 2.41mol/L, and add a certain amount of silver nitrate to make the silver nitrate concentration 2.41mol/L. 0.003mol/L, stir and mix evenly to obtain a mixed solution;

Put the washed polylactic acid fabric into the mixed solution, add it to the irradiation tube together with the reaction solution after it is completely soaked, pass nitrogen gas into the irradiation tube for 20 minutes, seal the irradiation tube after completion, and place it in the cobalt source chamber Carry out irradiation, the irradiation dose is 10kGy, and the irradiation dose rate is 50Gy/min;

After the irradiation, the reacted PLA fabric was transferred from the irradiation tube to an excess of anhydrous ethanol for soaking and washing for 20 hours, and then the soaked samples were placed in a blast drying oven at 60°C to dry to constant weight. Antibacterial polylactic acid fabric was obtained.

The ICP test was carried out on the obtained antibacterial polylactic acid fabric, and the silver loading was measured to be 89.9 mg/kg.

Experimental example

Experimental example 1

The grafting rate of the PLA-g-PVP sample of embodiment 1-6 gained is tested, and the formula for calculating the grafting rate is:

In the formula, GY is the graft ratio, W ₀ and W ₁ are the quality of the antibacterial PLA fabric samples before and after irradiation and grafting, respectively. The test results are shown in Figure 1a. The grafting rate of the PVP samples was tested, and the test results obtained are shown in Figure 1b.

It can be seen from Figure 1a that the grafting rate of the PLA-g-PVP sample increases with the increase of the NVP monomer concentration. When the monomer concentration increases from 0.78mol/L to 3.12mol/L, the grafting rate of the sample increases The ratio increased from 11.73% to 40.50%, indicating that the grafting reaction was dominant in this monomer concentration range.

It can be seen from Figure 1b that the grafting rate of PLA-g-PVP samples increases with the irradiation dose when the irradiation dose is lower than 25kGy, but after the irradiation dose exceeds 25kGy, Further increase of the irradiation dose makes the grafting rate of the samples decrease to a certain extent. This may be due to the simultaneous presence of grafting and degradation reactions in the reaction system. Under the condition of higher irradiation dose, the PVP polymer chains grafted on the surface of PLA fabrics have a greater degree of degradation reaction, and the grafted molecular chains are broken. Eventually, the grafting rate of the samples decreased.

Experimental example 2

The product samples obtained from Comparative Example 1, Example 1, and Examples 4-6 were subjected to infrared spectrum analysis, and the obtained infrared spectrum was shown in Figure 2. In Figure 2, curve (a)-Comparative Example 1, curve (b)- Example 1, curve (c) - example 4, curve (d) - example 5, curve (e) - example 6.

As can be seen in Figure 2, the samples were normalized with the characteristic peak of ester carbonyl of PLA fabric at 1745 cm ^-1 as the benchmark. In the infrared curve of PLA fabric, the characteristic peak of COC at 1086 cm ^-1 and the characteristic peaks of methyl group at 1446 cm ^-1 and 753 cm ^-1 can be observed. In the PLA-g-PVP sample curve, in addition to the above-mentioned characteristic peaks of PLA fabrics, the characteristic peaks at 1268 cm ^-1 are the C—N stretching vibration peaks on the pyrrolidone ring, and the characteristic peaks at 1439 cm ^-1 and 1422 cm ^-1 are The bending and rocking vibration peaks of methylene-CH ₂ - on the pyrrole ring, the characteristic peak at 1661 cm ^-1 is the characteristic absorption peak of the amide carbonyl-NC=O group in PVP, and the characteristic peak of this characteristic peak can be clearly observed. The size increases with the increase of PVP grafting rate. In addition, due to the excellent hydrophilic properties of the PVP long chains grafted on the PLA fabric, the characteristic peak of the hydroxyl group of water molecules centered at 3455 cm ^-1 can be clearly observed in the curve of the modified PLA fabric. It indicated that PVP was successfully grafted on PLA fabric.

Experimental example 3

The PLA-g-PVP samples obtained in Example 1 and Example 4-6 were tested by SEM, and the SEM images obtained are shown in Figure 3, wherein A-Example 1, B-Example 4, C-Example 5, D - Example 6.

It can be seen from Figure 3 that when the concentration of NVP monomer in the reaction system is low, the surface of the PLA-g-PVP sample obtained in Example 1 with a low graft ratio is relatively smooth. The content of PVP grafted on the surface increases, the degree of polymerization of PVP also increases, and adhesion occurs between fibers in the PLA fabric. When the graft ratio is 40.50%, the surface of the fibers inside the PLA fabric is very rough, and the PLA fibers are bonded. Serious, and cracks appear on the fiber surface. The SEM results showed that although the grafting rate of the PLA fabric was higher under the condition of high monomer concentration, the fibers of the PLA fabric itself became rough and damaged.

Experimental example 4

The product samples obtained in Comparative Example 1, Example 4 and Example 18 were subjected to XPS analysis, and the obtained results are shown in Figure 5 and Table 3. In Figure 5, a-Comparative example 1, b-Example 4, c-Example 18, (A) is the XPS spectrum of C-1s, (B) is the O-1s spectrum, (C) is N- The XPS spectrum of 1s, (D) is the XPS spectrum of Ag-3d. The fitted peak positions and corresponding chemical bond energies of the three sample elements are shown in Table 2.

Table 2

It can be seen from Figure 5 and Table 2 that in Figure 5(D), the peaks at binding energies of 368.0 eV and 374.0 correspond to Ag ⁰ 3d _5/2 and Ag ⁰ 3d _3/2 , and peaks at 368.8 and 374.9 eV, respectively Corresponding to Ag ⁺ 3d _5/2 and Ag ⁺ 3d _3/2 , indicating the distribution of Ag particles in the sample. The chemical bond changes in the sample were further analyzed. In the C1s spectrum (Fig. 5(A)), the peak at the binding energy of 284.8eV corresponds to the main peak of the carbon chain, and the peak at 289.2eV corresponds to the C=O double bond in the sample, 287.2 The peak at eV corresponds to the CO bond in the sample. A new peak at 286.0 eV can be fitted in the C1s plots of PLA-g-PVP and PLA-g-PVP-Ag samples, which corresponds to the C(=O)-N bond in the pyrrolidone ring, which proves that the surface of the PLA fabric is Successfully grafted PVP long chain. In the O1s spectrum (Fig. 5(B)), two characteristic peaks can be fitted to the PLA fabric and PLA-g-PVP samples, located at 533.8 eV and 532.1 eV, corresponding to C=O and CO, respectively. In the O1s spectrum of PLA-g-PVP-Ag, a silver-oxygen coordination peak appears at a lower binding energy of 531.6 eV, indicating that in this system, Ag and O atoms are connected by coordination bonds, while in PLA-g- In the N1s spectrum of PVP-Ag (Fig. 5(C)), a silver-nitrogen coordination peak at 394.6 eV can also be fitted, indicating that there is also coordination between Ag particles and N atoms in this system.

Experimental example 5

TGA test was performed on the polylactic acid fabrics obtained in Comparative Example 1, Example 4 and Example 14, and the obtained test results are shown in FIG. 6 . In Fig. 6, Fig. 6(a) is a TG curve, Fig. 6(b) is a DTG curve, A-Comparative Example 1, B-Example 4, C-Example 14.

It can be seen from Figure 6 that the modified fabric after grafting PVP appeared two weight decomposition stages in the TG curve. The first stage of thermal weight loss corresponds to the thermal decomposition of the PLA fabric, and the second stage of thermal weight loss corresponds to the decomposition of the PVP long chains grafted on the surface of the PLA fabric. The decomposition temperature of PVP is higher than that of PLA, but the initial decomposition temperature of the PLA fabric after grafting PVP can be obviously decreased. This is because the hydrophilicity of the long chain of PVP is very good, so that there is a certain amount of water in the modified PLA fabric. Molecule, PLA not only undergoes thermal decomposition during the heating process, but also undergoes a hydrolysis reaction at a lower temperature, which reduces the decomposition temperature of PLA and reduces the heat resistance. The _Tmax of the antibacterial polylactic acid fabric obtained in Example 14 is slightly higher than that of the polylactic acid fabric obtained in Example 4.

Experimental example 6

The hydrophilic performance of the PLA fabric was characterized by the water droplet soaking time, and the sample was tested by the OCA20 contact angle tester. , and record the soaking time in seconds. When the soaking time is less than 90s, the actual time is recorded. If the soaking time exceeds 90s, it is recorded as >90s, and the sample is determined not to be hydrophilic. The hydrophilic properties of the antibacterial polylactic acid fabrics obtained in Comparative Examples 1-2 and 13-15 were tested, and the test results obtained are shown in Table 3 below.

table 3

As can be seen from Table 3, the water droplet infiltration time of the polylactic acid fabrics obtained in Comparative Example 1 and Comparative Example 2 is greater than 90s and does not have hydrophilicity. Example 4 is the polylactic acid fabric of grafted PVP, and its water droplet infiltration time is only 0.6s, with excellent hydrophilicity, and the hydrophilicity decreases after Ag is loaded, but it can be seen that the water droplet infiltration time of the antibacterial PLA fabrics obtained in Examples 13-15 is significantly less than 50s, both less than Comparative Examples 1 and 2 Droplet wetting time of PLA fabrics. While the water droplet soaking time of Example 14 is less than 20s, the water droplet soaking time of Example 13 is only 4.1s. It shows that the hydrophilicity of PLA-g-PVP-Ag fabric is obviously better than that of PLA fabric and PLA-g-PAA-Ag fabric.

Experimental example 7

According to the absorption method in the second part of GB20944.2-2007 "Evaluation of Antibacterial Properties of Textiles", the antibacterial properties of the polylactic acid fabric of Comparative Example 1, the polylactic acid fabric obtained in Example 4 and the antibacterial polylactic acid fabric obtained in Examples 13-16 were tested. In the test, the standard pure cotton fabric was used as the standard sample, the strain selected for the test was Staphylococcus aureus, and the amount of bacterial solution was 0.2ml. , in Figure 7, a-Comparative Example 1, b-Example 4, c-Example 13, d-Example 14, (1) in each figure is an experimental control standard pure cotton fabric sample, (2) is an experimental Samples to be tested (ie, Comparative Example 1, Example 4, Example 13, and Example 14).

Table 4

As can be seen from Table 4, the antibacterial rate of the polylactic acid fabric obtained in Example 4 is 83%, indicating that PVP has certain antibacterial properties to the polylactic acid fabric, but the antibacterial properties of the antibacterial polylactic acid fabric containing Ag nanoparticles and PVP at the same time When the loading of Ag nanoparticles is more than 320mg/kg, the antibacterial rate is more than 99%, the antibacterial activity value can reach more than 5.5, and the antibacterial performance is excellent.

It can also be seen from the bacterial colony in FIG. 7 that after culturing Staphylococcus aureus with the samples of Comparative Example 1, Example 4 and Example 13-14 for 18 hours, the bacterial colonies of the samples of Example 13 and Example 14 were not cultivated. Colony growth, indicating that the antibacterial PLA fabric has excellent antibacterial properties.

Experimental example 8

According to the GB/T8629-2001 standard, the antibacterial polylactic acid fabrics loaded with AgNPs obtained in Examples 18 and 19 were tested for washability.

The antibacterial polylactic acid fabric of Example 18 was cut into a sample of 5 × 5 cm size, and the sample before washing was marked as A; the antibacterial polylactic acid fabric of Example 19 was cut into a sample of 5 × ^{5 cm 2 size} , and the sample before washing was marked as A'.

Using the ICP test, the silver loadings of the A and A' samples were measured to be 307.5 mg/kg and 1862.2 mg/kg, respectively, before the washfastness test was performed.

Put A and A' into the horizontal drum type washing machine together with the standard cotton fabric washing cloth, the total weight of the laundry is 2 ± 0.1Kg, the washing procedure is: the washing water temperature is 40 ± 3 ℃, and the washing water level is 10 cm. The washing time is 15min, rinse 3 times after washing, the water level is 13cm, the rinsing time is 3min, and the last dehydration time is 2min. The washed samples were flat-dried to constant weight at room temperature, the washed A samples were denoted as B, and the washed A' samples were denoted as B'.

The silver loadings of samples B and B' tested by ICP were 260.6 mg/kg and 1675.0 mg/kg, respectively.

The obtained washing resistance test results are shown in Figure 8. It can be concluded that after a certain intensity of washing, the silver content in the antibacterial polylactic acid fabric sample did not decrease significantly, indicating that the silver nanoparticles in the antibacterial polylactic acid fabric were loaded stably. Good washability.

The present invention has been described in detail above with reference to preferred embodiments and exemplary examples. However, it should be stated that these specific embodiments are only illustrative explanations of the present invention, and do not constitute any limitation to the protection scope of the present invention. Various improvements, equivalent replacements or modifications can be made to the technical content of the present invention and its embodiments without departing from the spirit and protection scope of the present invention, which all fall within the protection scope of the present invention. The scope of protection of the present invention is determined by the appended claims.

Claims (10)

1. An antibacterial polylactic acid fabric is characterized in that the antibacterial polylactic acid fabric is obtained by irradiation treatment of a polylactic acid fabric, NVP and a silver-containing compound, preferably, the water drop infiltration time of the antibacterial polylactic acid fabric is less than 50s, and the antibacterial rate is more than 90%.

2. An antibacterial polylactic acid fabric is characterized in that the antibacterial polylactic acid material is prepared by a method comprising the following steps:

step 1, preparing a solution containing NVP and a silver-containing compound;

step 2, soaking the polylactic acid fabric in the solution obtained in the step 1, and performing irradiation treatment;

and 3, carrying out post-treatment on the polylactic acid fabric subjected to the irradiation treatment in the step 2 to obtain the antibacterial polylactic acid fabric.

3. The antibacterial polylactic acid fabric according to claim 1,

in step 1, the silver-containing compound is silver nitrate, and the solvent in the solution is one or more selected from water, methanol, propanol and ethanol, preferably methanol, such as anhydrous methanol.

4. The antibacterial polylactic acid fabric according to claim 1,

in step 2, the irradiation treatment conditions are as follows: the irradiation source is a cobalt source, and the irradiation dose rate is 20-80 Gy/min, preferably 30-60 Gy/min.

5. A method for preparing an antimicrobial polylactic acid fabric, comprising:

step 1, preparing a solution containing NVP and a silver-containing compound;

step 2, soaking the polylactic acid fabric in the solution obtained in the step 1, and performing irradiation treatment;

and 3, carrying out post-treatment on the polylactic acid fabric subjected to the irradiation treatment in the step 2 to obtain the antibacterial polylactic acid fabric.

6. The method of claim 5, wherein the preparing the solution containing NVP and the silver-containing compound in step 1 comprises: adding NVP and a silver-containing compound into a solvent, mixing to obtain the solution,

in the solution, the concentration of NVP is 0.2-4 mol/L, and the concentration of silver ions is 0.0001-0.05 mol/L.

7. The method of claim 6, wherein the concentration of NVP in the solution is 0.6-3 mol/L and the concentration of silver ions is 0.0002-0.002 mol/L.

8. The method according to claim 5, wherein in step 2, the polylactic acid fabric is soaked in the solution obtained in step 1 for 10-50 min, preferably 15-40 min, such as 20-30 min.

9. The method of claim 5, wherein the post-processing comprises: and washing and drying the polylactic acid fabric after irradiation treatment, wherein the washing is washing for 20-40 h by using deionized water, and the drying is drying at 40-60 ℃ to constant weight.

10. An antibacterial polylactic acid fabric obtainable by the process according to any one of claims 5 to 9.

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