1. A preparation method of degradable non-woven fabric comprises the following steps:

carrying out melt spinning on polylactic acid, stretching, curling and cutting the obtained nascent fiber to obtain polylactic acid short fiber, laying the polylactic acid short fiber into a net, and fixing to obtain a PLA non-woven fabric base layer; the speed of the melt spinning is 500-1000 m/min, and the spinning temperature is lower than 200 ℃;

performing electrostatic spinning on the PLA solution to obtain a degradable non-woven fabric; the electrostatic spinning voltage is 18-22 KV, the receiving distance is 14-16 cm, and the flow rate is 0.9-1.1 mL/h.

2. The method according to claim 1, wherein the temperature of the electrospinning is 15 to 30 ℃ and the relative humidity of the electrospinning is 40 to 45% RH.

3. The method for preparing the PLA sheet according to claim 1, wherein the solvent in the PLA solution is N, N-dimethylformamide;

the mass ratio of the N, N-dimethylformamide to the PLA is 1.9-2.1: 1.

4. The production method according to claim 1, wherein the length of the polylactic acid staple fiber is 30 to 70 mm.

5. The method of claim 1, wherein the nascent fiber is stretched 4-7 times at 135-145 ℃.

6. The method according to claim 1, wherein the receiving plate used in the electrospinning is an aluminum receiving plate.

7. A degradable non-woven fabric prepared by the preparation method of any one of claims 1 to 6.

Background

With the development of society and the progress of technology, the living standard of people is greatly improved, more and more attention is paid to the improvement of living quality, and the attention to environmental protection is also brand-new. According to incomplete statistics, various waste textiles in the world are up to 3000 million tons each year, are less recycled as waste resources, but are directly buried or burned, and because synthetic chemical fiber textiles such as terylene, chinlon, acrylic fiber and the like are not easy to degrade, a large amount of land is occupied after being buried, and the damage to the soil environment is great; in addition, the textile containing the synthetic fiber can generate a large amount of toxic gas in the combustion process, so that the atmospheric pollution is caused, and the production and the life of human beings are greatly damaged. The degradation of the non-durable non-woven fabric is the most environment-friendly and practical method for solving the problem of a large amount of waste non-woven fabric.

Textile materials can be divided into, by fiber: natural fibers, synthetic fibers and novel fibers. Wherein, the natural fiber can be divided into plant sources according to the source, including cellulose, hemicellulose, lignin, starch, polysaccharides and hydrocarbon composed of cell wall, the animal source mainly includes crustacean such as shrimp and crab; the traditional synthetic fibers comprise polypropylene fibers, polyester fibers and the like, but the traditional synthetic fibers are not easy to degrade; polylactic acid (PLA), Polycaprolactone (PCL), biopolyester (PHA) and polyvinyl alcohol (PVA) in novel fibers are increasingly used due to degradability. The polylactic acid has excellent biocompatibility and absorbability, and simultaneously, has no toxicity or irritation, and can be completely decomposed into CO in nature₂And H₂O, being non-polluting to the environment, is currently one of the most promising biodegradable polymers. The polylactic acid can be directly made into non-woven fabric by using a spinning-bonding method or a melt-blowing method, and also can be made into single fiber by spinning first and then made into the non-woven fabric by a dry method or a wet method. However, the function controllability of the non-woven fabrics prepared by the methods is poor.

Disclosure of Invention

In view of the above, the present invention aims to provide a degradable nonwoven fabric and a preparation method thereof, wherein the nonwoven fabric prepared by the method has good antibacterial property.

The invention provides a preparation method of degradable non-woven fabric, which comprises the following steps:

carrying out melt spinning on polylactic acid, stretching, curling and cutting the obtained nascent fiber to obtain polylactic acid short fiber, laying the polylactic acid short fiber into a net, and fixing to obtain a PLA non-woven fabric base layer; the speed of the melt spinning is 500-1000 m/min, and the spinning temperature is lower than 200 ℃;

performing electrostatic spinning on the PLA solution to obtain a degradable non-woven fabric; the electrostatic spinning voltage is 18-22 KV, the receiving distance is 14-16 cm, and the flow rate is 0.9-1.1 mL/h.

In the present invention, the temperature of the melt spinning is lower than 200 ℃, preferably lower than 190 ℃ to ensure smooth spinning.

In the invention, the temperature of the electrostatic spinning is 15-30 ℃, and the relative humidity of the electrostatic spinning is 40-45% RH.

In the invention, the solvent in the PLA solution is N, N-dimethylformamide;

the mass ratio of the N, N-dimethylformamide to the PLA is 1.9-2.1: 1.

In the invention, the length of the polylactic acid short fiber is 30-70 mm.

In the invention, the nascent fiber is stretched 4-7 times at 135-145 ℃.

In the invention, the receiving polar plate adopted by the electrostatic spinning is an aluminum receiving plate.

According to the invention, by controlling the parameters of electrostatic spinning, the Taylor cone of the jet flow can be maintained in a stable state when the jet flow is sprayed out of the needle head, and no liquid drop drops in the spinning process, so that a smooth and flat nanofiber membrane is obtained. In a specific embodiment, the voltage of the electrostatic spinning is 20KV, the receiving distance is 15cm, and the flow rate is 1 mL/h.

In the present invention, the obtained degradable nonwoven fabric is preferably placed in a vacuum drying oven overnight to volatilize the remaining organic solvent.

In the invention, the non-woven fabric base layer and the surface layer are mainly combined through Van der Waals force between molecules, and in addition, the base layer is a conventional non-woven fabric and has certain porosity; in the electrostatic spinning process of the surface layer, due to the action of an electric field, part of nano-scale PLA fibers can be embedded into gaps of the base layer, and the binding force between the surface layer and the base layer is strengthened.

The invention provides a degradable non-woven fabric which is prepared by the preparation method of the technical scheme.

The degradable non-woven fabric is non-woven fabric, has strong function controllability, can meet the environmental protection and the service performance of product materials at the same time, also has washing resistance, broad-spectrum antibacterial property and ecological safety, and has good market prospect.

The invention provides a preparation method of degradable non-woven fabric, which comprises the following steps: carrying out melt spinning on polylactic acid, stretching, curling and cutting the obtained nascent fiber to obtain polylactic acid short fiber, laying the polylactic acid short fiber into a net, and fixing to obtain a PLA non-woven fabric base layer; the speed of the melt spinning is 500-1000 m/min, and the spinning temperature is lower than 200 ℃; performing electrostatic spinning on the PLA solution to obtain a degradable non-woven fabric; the electrostatic spinning voltage is 18-22 KV, the receiving distance is 14-16 cm, and the flow rate is 0.9-1.1 mL/h. The non-woven fabric prepared by the process has good broad-spectrum antibacterial property and washing fastness. The experimental results show that: before washing, the bacteriostasis rates of escherichia coli, staphylococcus aureus and candida albicans are all over 99 percent; after 50 times of washing, the bacteriostasis rate of escherichia coli, staphylococcus aureus and candida albicans is over 87 percent.

Drawings

FIG. 1 is a schematic view of a surface layer preparation apparatus of an electrospun PLA nonwoven fabric of the present invention;

fig. 2 is a schematic cross-sectional structure diagram of the degradable non-woven fabric provided by the invention.

Detailed Description

In order to further illustrate the present invention, the following examples are provided to describe a degradable nonwoven fabric and a method for preparing the same in detail, but they should not be construed as limiting the scope of the present invention.

Example 1

(1) Preparing a PLA non-woven fabric base layer: melt spinning using a screw extruder is easy to depolymerize at high temperature due to polylactic acid, and therefore, the chips are sufficiently dried before spinning to remove moisture. At the same time, the spinning temperature is 180 ℃. The spinning speed is 500 m/min-1000 m/min, the nascent fiber is stretched 4 times to 7 times at 140 ℃, and then is crimped and cut to prepare the polylactic acid short fiber with the using and processing performance. The fiber used for the dry-laid non-woven fabric has a cut length of 30mm to 70 mm.

(2) Preparing a PLA non-woven fabric surface layer by electrostatic spinning: fixing the base layer non-woven fabric prepared in the step (1) on a specific aluminum metal plate, wherein the metal plate is used as a receiving polar plate for electrostatic spinning. Preparing a PLA solution from a solvent DMF (N, N-dimethylformamide) and PLA powder according to a mass ratio of 2:1, sucking the PLA solution into a 5ml standard syringe, connecting a flat-mouth stainless steel needle with the inner diameter of 0.84mm, and fixing the syringe on a syringe pump. The process parameters of electrostatic spinning are selected as follows: the flow rate of the injector is 1mL/h, the spinning voltage is 30KV, and the receiving distance is 15 cm. Under the condition of the parameter, the Taylor cone of the jet flow is kept in a stable state when the jet flow is sprayed out of the needle head, no liquid drop is dropped in the spinning process, and a flat and smooth nanofiber membrane is obtained, namely the non-woven fabric can be degraded; the mixture was left overnight in a vacuum oven to evaporate the remaining organic solvent for later characterization. The electrostatic spinning is carried out at room temperature, and the relative humidity is controlled to be 40-45% RH by a dehumidifier.

Example 2

(1) Preparing a PLA non-woven fabric base layer: melt spinning is carried out by using a screw extruder, and because polylactic acid is easy to depolymerize at high temperature, slices are fully dried before spinning, and moisture is removed; while the temperature of spinning was 185 ℃. The spinning speed is 500 m/min-1000 m/min. The obtained nascent fiber is stretched at 140 ℃ by 4 times to 7 times, and then is crimped and cut to obtain the polylactic acid short fiber with service and processing properties. The fiber used for the dry-laid non-woven fabric has a cut length of 30mm to 70 mm.

(2) Preparing a PLA non-woven fabric surface layer by electrostatic spinning: fixing the base layer non-woven fabric prepared in the step (1) on an aluminum metal plate, wherein the metal plate is used as a receiving polar plate for electrostatic spinning. Preparing a PLA solution from a solvent DMF (N, N-dimethylformamide) and PLA powder according to the mass ratio of 2:1, sucking the prepared PLA solution into a 5ml standard syringe, connecting a flat-mouth stainless steel needle with the inner diameter of 0.84mm, and fixing the syringe on a syringe pump. The process parameters of electrostatic spinning are selected as follows: the flow rate of the injector was 1ml/h, the spinning voltage was 20KV, and the reception distance was 25 cm. Under the condition of the parameter, the Taylor cone of the jet flow can be maintained in a stable state when the jet flow is sprayed out of the needle head, and no liquid drop drops in the spinning process, so that a flat and smooth nanofiber membrane is obtained, and the non-woven fabric can be degraded. The mixture was left overnight in a vacuum oven to evaporate the remaining organic solvent for later characterization. The electrostatic spinning is carried out at room temperature, and the relative humidity is controlled to be 40-45% RH by a dehumidifier.

Example 3

(1) Preparing a PLA non-woven fabric base layer: melt spinning is carried out by using a screw extruder, and because polylactic acid is easy to depolymerize at high temperature, slices are fully dried before spinning, and moisture is removed; at the same time, the spinning temperature is 190 ℃, the spinning speed is 500 m/min-1000 m/min, the nascent fiber is stretched 4 times to 7 times at 140 ℃, and then is curled and cut off to prepare the polylactic acid short fiber with the use and processing performance, and the cutting length of the fiber used for dry-laid non-woven fabric is 30 mm-70 mm.

(2) Preparing a PLA non-woven fabric surface layer by electrostatic spinning: fixing the base layer non-woven fabric prepared in the step (1) on an aluminum metal plate, wherein the metal plate is used as a receiving polar plate for electrostatic spinning. Preparing a PLA solution from a solvent DMF (N, N-dimethylformamide) and PLA powder according to the mass ratio of 2:1, sucking the prepared PLA solution into a 5ml standard syringe, connecting a flat-mouth stainless steel needle with the inner diameter of 0.84mm, and fixing the syringe on a syringe pump. The process parameters of electrostatic spinning are selected as follows: the flow rate of the injector is 1ml/h, the spinning voltage is 30KV, the receiving distance is 25cm, and under the parameter condition, the Taylor cone of the jet flow when the jet flow is sprayed out of the needle head is maintained in a stable state, and no liquid drop drops in the spinning process, so that a flat and smooth nanofiber membrane is obtained, and the non-woven fabric can be degraded. The mixture was left overnight in a vacuum oven to evaporate the remaining organic solvent for later characterization. The electrostatic spinning is carried out at room temperature, and the relative humidity is controlled to be 40-45% RH by a dehumidifier.

The invention carries out antibacterial property test on the prepared degradable non-woven fabric, and according to GB/T20944.3-2008 < evaluation of antibacterial property of textile part 3: and (4) testing the bacteriostasis rates of escherichia coli (AATCC 8099), staphylococcus aureus (AATCC 6538) and candida albicans (AATCC10231) by using an oscillation method, wherein the bacteriostasis rates of the escherichia coli (AATCC 8099), the staphylococcus aureus (AATCC 6538) and the candida albicans (AATCC10231) are 99.99% before washing.

Bacteriostatic activity test after 50 washes: the lining cloth obtained in the example is washed by 2g/L washing powder at 40 ℃ for 5min according to GB/T8629-2001, household washing and drying program for textile test, washed and rinsed 2 times by clean water, dehydrated and dried, wherein the washing is one time, the sample is washed 50 times repeatedly, and is placed in an environment with the temperature of (20 +/-2) DEG C and the relative humidity of 65 +/-2% for humidifying for 24 hours, and the antibacterial activity after washing is tested.

Specific test results of the degradable nonwoven fabrics prepared in examples 1 to 3 are shown in Table 1:

table 1 results of performance tests of the degradable nonwoven fabrics prepared in examples 1 to 3.

TABLE 2 requirement of antibacterial index for FZ/T73023 and 2006 antibacterial knitwear

As can be seen from the test results of table 1: the non-woven fabric obtained by the method has good broad-spectrum antibacterial property and washing fastness.

From the above embodiments, the invention provides a preparation method of degradable non-woven fabric, which comprises the following steps: carrying out melt spinning on polylactic acid, stretching, curling and cutting the obtained nascent fiber to obtain polylactic acid short fiber, laying the polylactic acid short fiber into a net, and fixing to obtain a PLA non-woven fabric base layer; the speed of the melt spinning is 500-1000 m/min, and the spinning temperature is lower than 200 ℃; performing electrostatic spinning on the PLA solution to obtain a degradable non-woven fabric; the electrostatic spinning voltage is 18-22 KV, the receiving distance is 14-16 cm, and the flow rate is 0.9-1.1 mL/h. The non-woven fabric prepared by the process has good broad-spectrum antibacterial property and washing fastness. The experimental results show that: before washing, the bacteriostasis rates of escherichia coli, staphylococcus aureus and candida albicans are all over 99 percent; after 50 times of washing, the bacteriostasis rate of escherichia coli, staphylococcus aureus and candida albicans is over 87 percent.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.