CN111691060A - High polymer fiber based on instantaneous pressure-release spinning method, and preparation method and application thereof - Google Patents

Abstract

The invention discloses a method for preparing high polymer fibers based on an instantaneous pressure-releasing spinning method. After being stirred and stabilized, a supercritical spinning fluid is formed. The supercritical spinning fluid undergoes phase separation in the open atmosphere released by the spinning nozzle and is transformed into carbon dioxide gas, plasticizers and cured polymers. The polymer forms polymer fibers under the action of plasticizer replacement and instantaneous pressure-releasing differential drafting. The invention also discloses the high polymer fiber prepared by the above method and its application. The preparation method provided by the invention can obtain higher spinning pressure difference and spinning jet speed than the flash evaporation method, and can avoid the recovery and treatment of organic solvent, and the fiber diameter of the prepared polymer fiber is 0.5-5 μm. The invention belongs to the technical field of high polymer non-woven fabric preparation, and is suitable for the field of limited-time medical protective clothing.

Description

Polymer fiber based on instantaneous pressure release spinning method, its preparation method and application

technical field

The invention belongs to the technical field of high polymer non-woven fabric preparation, and relates to the preparation of a high polymer fiber, in particular to a high polymer fiber based on an instantaneous pressure release spinning method, a preparation method and an application thereof.

Background technique

Non-woven fabric is a fabric that does not require spinning or weaving. It only orients or randomly arranges textile staple fibers or filaments to form a web structure, which is then reinforced by mechanical, thermal bonding or chemical methods. . Non-woven fabric is a new type of fiber product with soft, breathable and flat structure formed directly by high polymer chips, short fibers or filaments through various web forming methods and consolidation techniques.

The uses of non-woven fabrics are very wide, and the main uses can be roughly divided into: related to medical and sanitary fabrics, home decoration fabrics, clothing fabrics, industrial fabrics, agricultural fabrics, etc. Among them, medical and sanitary cloths involve surgical gowns, protective clothing, sterilization wraps, masks, diapers, women's sanitary napkins, etc.

The outbreak of the new coronavirus pneumonia in 2020 has spread to the world and is gradually worsening. The outbreak of the epidemic has caused a sharp increase in the demand for masks and protective clothing. The output of various raw materials for masks and protective clothing, especially non-woven fabrics, has become an important factor restricting the production speed of both. At the same time, medical defense work has put forward higher requirements for the barrier properties, vapor permeability and reusability of masks and protective clothing.

Studies have shown that by regulating the fiber fineness of non-woven fabrics, the barrier properties, vapor permeability comfort and reusability of medical protective clothing can be systematically solved. When the fiber diameter of the nonwoven fabric reaches the sub-micron scale, nano-effects can be formed at the "solid-gas" and "solid-liquid" interfaces between the fibers and the outside world, forming a unidirectional moisture-conducting film. The specific performance is that vapor molecules can be discharged through the fiber membrane, and large-scale substances such as particles and droplets can be effectively blocked. Therefore, for high-end medical protective clothing, the development of microfiber nonwovens (UFN) is the core to improve the key performance of medical protective clothing such as filtration barrier and comfort. focus. At present, the methods of industrially preparing nonwovens, such as spunbond method, sea-island type or orange petal type composite spinning, meltblown method, etc., are difficult to construct microfiber aggregates with high barrier properties. However, to construct UFN by electrospinning, solution jet spinning and other methods, the product needs to be processed in multiple steps or compounded with other materials, resulting in poor mechanical properties and low production efficiency. Centrifugal spinning and super-stretching methods can also be used to construct UFN, but they are still in the laboratory exploration stage, and it is difficult to achieve industrial transformation in the short term. Therefore, it is of great significance to establish a UFN one-step forming method that is simple and easy to operate, has a wide range of applications and excellent product performance, and is of great significance for the promotion of UFN industrialization and the active response to the new coronavirus epidemic and major safety and health incidents.

The flash evaporation method is a method of dissolving polyethylene in an organic solvent (such as toluene, xylene, etc.) under high temperature and high pressure, and using a solution spinning dry process to prepare non-woven fabrics, and the technical process of DuPont is strictly confidential. Only a few universities and enterprises have done exploratory research. For example, the Mark A. McHugh group of Johns Hopkins University has done some research on the supercritical solubility and phase equilibrium law of polymers in alkanes, halogenated hydrocarbons and other solvent systems, and summarized the phase transition of polymer solutions. Thermodynamic laws; Kim's group at the Korea Institute of Science and Technology prepared L-lactide filaments by flash spinning with fiber diameters of 0.32-0.47 mm. In addition, there are problems of large solvent pollution and controllability of fiber morphology in the production process of flash evaporation non-woven fabrics.

In view of the high-end demand for reusable medical protective clothing, if a safety protection material with high barrier, high wear resistance and high moisture permeability can be manufactured, it will provide a powerful technology for the comfort and reuse of medical masks and protective clothing support.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for preparing polymer fibers based on the instantaneous pressure-releasing spinning method. The problems of solvent pollution and fiber morphology controllability in the textile production process;

The second object of the present invention is to provide a polymer fiber prepared based on the above-mentioned preparation method;

Another object of the present invention is to provide the application of the above-mentioned polymer fibers for preparing safety protection materials with high barrier properties, high abrasion resistance and high moisture permeability.

The present invention is to realize the above-mentioned purpose, and the technical scheme adopted is as follows:

A kind of preparation method of high polymer fiber based on instantaneous pressure release spinning method is carried out according to the following sequence of steps:

1. Transport the polymer and plasticizer into the supercritical kettle, and introduce supercritical carbon dioxide in a stirring state to form a supercritical spinning fluid after stabilization;

2. In an open atmospheric environment where the supercritical spinning fluid is released instantaneously through the spinning nozzle at a speed of 200-300 m/s, the supercritical spinning fluid rapidly changes from the supercritical state under a high pressure difference of 100-200. Separation and conversion into carbon dioxide gas, plasticizer and solidified high polymer, in the above process, the solidified high polymer forms polymer fiber under the action of plasticizer replacement and instantaneous pressure differential drafting.

As a limitation: the mass ratio of the high polymer and the plasticizer is 70-95:5-30.

As a second limitation: the high polymer is polyolefin, polyester or polyamide;

The polyolefin is one of polypropylene and polyethylene;

The polyester is polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polylactic acid, polyhydroxy fatty acid ester, polyglycolic acid, polysuccinic acid A kind of butanediol ester;

The polyamide is one of polyamide 6, polyamide 66, polyamide 56 and polyamide 1010.

As a third limitation: the plasticizer is one or two composite additives of dioxane, cyclohexane, dichloromethane, isopropanol, and ethylene glycol monomethyl ether.

As the fourth limitation: the temperature environment of the supercritical kettle is 110-190 ^oC .

As a fifth limitation: the pressure of the supercritical fluid is 8-18 MPa.

The present invention also provides a polymer fiber, which is made by the above-mentioned preparation method of the polymer fiber based on the instant pressure-releasing spinning method.

As a limitation: the diameter of the polymer fibers is 0.5-5 μm.

The present invention further provides an application of the above-mentioned polymer fiber, which is used to prepare a polymer non-woven fabric.

Because the present invention adopts the above-mentioned technical scheme, compared with the prior art, the technical progress achieved is:

(1) The instant pressure-releasing spinning method of the present invention is based on the supercritical fluid of high polymer as the spinning solution, which can not only obtain a higher spinning pressure difference and spinning jet rate than the flash method, but also effectively. Reduce or even avoid the recovery and disposal of organic solvents;

(2) The supercritical spinning fluid of the present invention undergoes phase separation during the jetting process, and the fibers of the resulting polymer non-woven fabric have higher vapor permeability and barrier properties, and also have the characteristics of good wear resistance, especially Suitable for preparing limited medical protective clothing;

(3) The fiber diameter of the polymer non-woven fabric of the present invention reaches 0.5 to 5 μm;

(4) The preparation method of the present invention does not cause solvent pollution during the production process, and the morphology and fine structure of the prepared fibers are controllable.

The invention is suitable for the technical field of high polymer ultrafine non-woven fabrics, and is used for preparing 0.5-5 μm non-woven fabrics.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention.

In the attached image:

FIG. 1 is a schematic diagram of the device structure of Embodiments 1-10 of the present invention;

Fig. 2 is the scanning electron microscope picture of the polyethylene micro-nano fiber of the embodiment of the present invention 1;

FIG. 3 is a physical diagram of the polyethylene micro/nano fiber non-woven fabric of Example 1 of the present invention.

In the figure: 1. Supercritical gas input port, 2. Raw material port, 3. Supercritical kettle, 4. Air amplifier, 5. First collecting roller, 6. Godet roller, 7. Second collecting roller.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

Example 1 Preparation method of polyethylene micro-nanofibers based on instantaneous pressure-releasing spinning method

This embodiment is carried out according to the following sequence of steps:

1. As shown in Figure 1, 90kg of high-density polyethylene and 10kg of plasticizer cyclohexane are metered from the raw material port 2 to the 150 ^o C supercritical kettle 3, and the supercritical gas input port is under agitation. 1. Introduce supercritical carbon dioxide to 18MPa and stabilize for 2h to form supercritical spinning fluid;

2. In an open atmosphere where the supercritical spinning fluid is instantaneously released through a circular nozzle at a speed of 200m/s, the supercritical spinning fluid rapidly changes from the supercritical state under the high pressure difference of 150% produced by the air amplifier 4. Separation and conversion into carbon dioxide gas, cyclohexane gas and solidified high-density polyethylene. In the above process, the solidified high-density polyethylene forms polyethylene micro-nano under the action of plasticizer replacement and instantaneous pressure release external force drafting. fiber.

Figure 2 is a scanning electron microscope image of the polyethylene micro-nano fibers prepared in this example. It can be seen from the figure that the polyethylene micro-nano fibers prepared in this example are circular, and their diameters are about 0.8-3 μm. The morphology and microstructure of the prepared fibers are controllable.

In this embodiment, high-density polyethylene can be replaced with high-density polypropylene, and finally polypropylene micro-nano fibers can be prepared.

Example 2 Preparation method of polyamide 6 micro-nano fibers based on instantaneous pressure-releasing spinning method

This embodiment is carried out according to the following sequence of steps:

One, as shown in Figure 1, after the polyamide 6 slices 70kg, plasticizer isopropanol 15kg and methylene dichloride 15kg are measured, transported from the raw material port 2 to the 130 ^℃ supercritical still 3, under agitation Supercritical carbon dioxide was introduced from the supercritical gas input port 1 to 12MPa, and the supercritical spinning fluid was formed after stabilizing for 3 hours;

2. In an open atmosphere where the supercritical spinning fluid is instantaneously released through a circular nozzle at a speed of 250m/s, the supercritical spinning fluid rapidly changes from the supercritical state under the high pressure difference of 180% produced by the air amplifier 4. Separation and conversion into carbon dioxide gas, isopropanol gas, dichloromethane gas and solidified polyamide 6, in the above process, the solidified polyamide 6 forms polyamide 6 under the action of plasticizer replacement and instantaneous pressure release external force drafting. Amide 6 micro-nano fibers.

After testing, the polyamide 6 micro-nano fibers prepared in this example have a circular structure with a diameter of about 0.5-2 μm.

Example 3 Preparation method of polylactic acid micro-nano fibers based on instantaneous pressure-releasing spinning method

This embodiment is carried out according to the following sequence of steps:

1. As shown in Figure 1, 95kg of polylactic acid slices and 5kg of plasticizer dioxane are measured and transported from raw material port 2 to 110 ^° C supercritical still 3, and under agitation, from the supercritical gas input port 1. Introduce supercritical carbon dioxide to 8MPa and stabilize for 2h to form supercritical spinning fluid;

2. In an open atmosphere where the supercritical spinning fluid is instantaneously released through a circular nozzle at a speed of 200m/s, the supercritical spinning fluid rapidly changes from the supercritical state under the high pressure difference of 100% produced by the air amplifier 4. Separation and conversion into carbon dioxide gas, dioxane gas and solidified polylactic acid, in the above process, the solidified polylactic acid forms polylactic acid micro-nano fibers under the action of plasticizer replacement and instantaneous pressure release external force drafting.

After testing, the polylactic acid micro-nano fibers prepared in this example have a circular structure with a diameter of about 0.5-3 μm.

Example 4 Preparation method of polyethylene terephthalate micro-nano fibers based on instantaneous pressure-releasing spinning method

This embodiment is carried out according to the following sequence of steps:

1. As shown in Figure 1, 85kg of polyethylene terephthalate slices, 15kg of plasticizer ethylene glycol monomethyl ether are measured and transported from raw material port 2 to 190 ^℃ of supercritical stills 3, in In a stirring state, supercritical carbon dioxide is introduced from the supercritical gas input port 1 to 12MPa, and the supercritical spinning fluid is formed after stabilizing for 3 hours;

2. In an open atmosphere where the supercritical spinning fluid is instantaneously released through a circular nozzle at a speed of 300m/s, the supercritical spinning fluid rapidly changes from the supercritical state under the high pressure difference of 200% produced by the air amplifier 4. Separation and conversion into carbon dioxide gas, ethylene glycol monomethyl ether gas and solidified polyethylene terephthalate, in the above process, the solidified polyethylene terephthalate in the plasticizer replacement and instantaneous Polyethylene terephthalate micro-nano fibers are formed under the action of pressure release and external force drafting.

After testing, the polyethylene terephthalate micro-nanofibers prepared in this example have a circular structure with a diameter of about 1-5 μm.

Example 5 Preparation method of polybutylene succinate micro-nano fibers based on instantaneous pressure-releasing spinning method

This embodiment is carried out according to the following sequence of steps:

1. As shown in Figure 1, after measuring 85kg of polybutylene succinate slices and 15kg of plasticizer methylene chloride, transport from raw material port 2 to 130 ^o C supercritical still 3, and under agitation, from Supercritical gas input port 1 introduces supercritical carbon dioxide to 10MPa, and forms supercritical spinning fluid after stabilizing for 2 hours;

2. In an open atmosphere where the supercritical spinning fluid is instantaneously released through a circular nozzle at a speed of 200m/s, the supercritical spinning fluid rapidly changes from the supercritical state under the high pressure difference of 130% produced by the air amplifier 4. Separation and conversion into carbon dioxide gas, dichloromethane gas and solidified polybutylene succinate. During the above process, the solidified polybutylene succinate is stretched by plasticizer replacement and instantaneous pressure release external force. Under the action of polybutylene succinate micro-nano fibers are formed.

After testing, the polybutylene succinate micro-nanofibers prepared in this example have a circular structure with a diameter of about 1-5 μm.

In the embodiment 1-5, only five kinds of high polymers are used as raw material distances to illustrate, and in actual production, the high polymers used can also be replaced with polytrimethylene terephthalate, polybutylene terephthalate, polybutylene terephthalate, Hydroxy fatty acid ester, polyglycolic acid, polyamide 66, polyamide 56, and polyamide 1010 are finally made into corresponding high polymer micro-nano fibers.

Similarly, the plasticizer used can also be replaced with isopropanol, or a composite of any two of dioxane, cyclohexane, dichloromethane, isopropanol, and ethylene glycol monomethyl ether. Auxiliary.

Example 6 Application of a polyethylene micro-nano fiber

This example provides an application of the polyethylene micro-nano fibers prepared in Example 1. As shown in Figure 1, the polyethylene micro-nano fibers can be used to obtain high-density polyethylene non-woven fabrics through electrostatic fiber opening and hot rolling. During the preparation process, the polyethylene micro-nano fibers form high-density polyethylene on the conveyor belt driven by the first collection roller The density polyethylene non-woven fabric is further sorted and collected under the driving of the godet roll 6 and the second collection roll 7 .

As shown in Figure 3 is the high density polyethylene non-woven fabric prepared in this example. After testing, the high-density polyethylene non-woven fabric has an average water resistance of 19.5 kPa, anti-penetration resistance of synthetic blood reaching grade 4, and the moisture permeability of the finished product reaches 9170g/(m ² *d).

Example 7 Application of a kind of polyamide 6 micro-nano fiber

This example provides an application of the polyamide 6 micro-nano fibers prepared in Example 2. As shown in FIG. 1 , the polyamide 6 micro-nano fibers can be used to obtain polyamide 6 non-woven fabrics through electrostatic fiber opening and hot rolling. During the preparation process, the polyamide 6 micro-nano fibers are formed on the conveyor belt driven by the first collection roller 5 The polyamide 6 non-woven fabric is further sorted and collected by the godet roll 6 and the second collection roll 7.

After testing, the average water resistance of the polyamide 6 non-woven fabric is 12.5kPa, the penetration resistance of synthetic blood reaches grade 3, and the moisture permeability of the finished product reaches 10240g/(m ² *d).

Example 8 Application of a kind of polylactic acid micro-nano fiber

This example provides an application of the polylactic acid micro-nano fibers prepared in Example 3. As shown in Figure 1, the polylactic acid micro-nano fibers can be used to obtain a polylactic acid non-woven fabric through electrostatic fiber opening and hot rolling. During the preparation process, the polylactic acid micro-nano fibers are formed on the conveyor belt driven by the first collection roller 5 to form polylactic acid The cloth is spun and further sorted and collected by the godet roll 6 and the second collection roll 7 .

After testing, the average anti-permeability of the polylactic acid non-woven fabric is 13.5kPa, the anti-synthetic blood penetration and penetration reaches grade 3, and the moisture permeability of the finished product reaches 9150g/(m ² *d).

Example 9 Application of polyethylene terephthalate micro-nano fibers

This example provides an application of the polyethylene terephthalate micro-nano fibers prepared in Example 3. As shown in Figure 1, the polyethylene terephthalate micro-nano fibers can be used to obtain polyethylene terephthalate non-woven fabrics through electrostatic fiber opening and hot rolling. During the preparation process, polyethylene terephthalate The polyethylene terephthalate micro-nano fibers are formed on the conveyor belt driven by the first collecting roller 5 to form a polyethylene terephthalate non-woven fabric, and are further sorted and collected under the driving of the godet roller 6 and the second collecting roller 7 .

After testing, the polyethylene terephthalate non-woven fabric has an average water resistance of 14.1kPa, a synthetic blood penetration resistance of grade 3, and a finished moisture permeability of 10250g/(m ² *d).

Embodiment 10 A kind of application of polybutylene succinate micro-nano fiber

This example provides an application of the polybutylene succinate micro-nano fibers prepared in Example 3. As shown in Figure 1, the polybutylene succinate micro-nano fibers can be used to obtain a polybutylene succinate non-woven fabric through electrostatic fiber opening and hot rolling. During the preparation process, the polybutylene succinate The ester micro-nano fibers are formed on the conveyor belt driven by the first collecting roller 5 to form a polybutylene succinate non-woven fabric, and are further sorted and collected under the driving of the godet roller 6 and the second collecting roller 7 .

After testing, the average water resistance of the polybutylene succinate non-woven fabric is 16.3kPa, the penetration resistance of synthetic blood reaches grade 3, and the moisture permeability of the finished product reaches 11130g/(m ² *d).

The non-woven fabrics prepared in Examples 6-10 can be used to prepare limited-time medical protective clothing.

Claims (9)

1. A preparation method of high polymer fiber based on an instantaneous pressure-release spinning method is characterized by comprising the following steps in sequence:

firstly, conveying a high polymer and a plasticizing auxiliary agent into a supercritical kettle, introducing supercritical carbon dioxide under a stirring state, and forming supercritical spinning fluid after stabilization;

and secondly, in an open atmosphere environment where the supercritical spinning fluid is instantaneously released at a speed of 200-300 m/s through a spinning nozzle, the supercritical spinning fluid is rapidly subjected to phase separation from a supercritical state under a high pressure difference of 100-200 to be converted into carbon dioxide gas, a plasticizing auxiliary agent and a solidified high polymer, and in the process, the solidified high polymer forms high polymer fibers under the action of plasticizing auxiliary agent displacement and instantaneous pressure-release differential drafting.

2. The method for preparing a high polymer fiber based on an instant pressure-release spinning method according to claim 1, wherein: the mass ratio of the high polymer to the plasticizing auxiliary agent is 70-95: 5-30.

3. The method for preparing a high polymer fiber based on the instant pressure-release spinning method according to claim 1 or 2, wherein: the high polymer is polyolefin, polyester or polyamide;

the polyolefin is one of polypropylene and polyethylene;

the polyester is one of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polylactic acid, polyhydroxyalkanoate, polyglycolic acid and polybutylene succinate;

the polyamide is one of polyamide 6, polyamide 66, polyamide 56 and polyamide 1010.

4. The method for preparing a high polymer fiber based on the instant pressure-release spinning method according to claim 1 or 2, wherein: the plasticizing auxiliary agent is one or two of dioxane, cyclohexane, dichloromethane, isopropanol and ethylene glycol monomethyl ether.

5. The method for preparing a high polymer fiber based on the instant pressure-release spinning method according to claim 1 or 2, wherein: the temperature environment of the supercritical kettle is 110-190%^oC。

6. The method for preparing a high polymer fiber based on the instant pressure-release spinning method according to claim 1 or 2, wherein: the pressure of the supercritical fluid is 8-18 MPa.

7. A high polymer fiber characterized by: the polymer fiber is prepared by the method for preparing the polymer fiber based on the instant pressure-release spinning method according to any one of claims 1 to 6.

8. The polymer fiber according to claim 7, wherein: the diameter of the high polymer fiber is 0.5-5 μm.

9. A use of the polymer fiber according to claim 7 or 8, wherein: the high polymer fiber is used for preparing high polymer non-woven fabrics.

Images