阅读说明：本技术 一种高韧性碳纳米纤维增强无纺布的制备方法 (Preparation method of high-toughness carbon nanofiber reinforced non-woven fabric ) 是由 程同恩 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种高韧性碳纳米纤维增强无纺布的制备方法,包括如下步骤：将多壁碳纳米管、盐酸混合,超声处理,加入硝酸溶液,继续超声处理,过滤后水洗,干燥得到预处理碳纳米管；将预处理碳纳米管送入转矩流变仪中,继续加入聚乳酸、β-环糊精,热处理后冷却,粉碎,采用静电纺丝法纺丝得到改性碳纳米纤维；将聚丙烯、海藻酸钠、壳聚糖、辛烯基琥珀酸淀粉钠、氧化钇、分散剂搅拌均匀得到预混料；将预混料、改性碳纳米纤维、玻璃纤维熔融挤出,将所得熔体依次经过滤器、计量泵后输送至纺丝组件中,经喷丝孔喷出,在离喷丝板12-15cm处进行风冷,牵伸后经过分丝落到成网帘上铺成纤维网,热压辊加固,烫光得到高韧性碳纳米纤维增强无纺布。(The invention discloses a preparation method of a high-toughness carbon nanofiber reinforced non-woven fabric, which comprises the following steps: mixing a multi-walled carbon nanotube with hydrochloric acid, carrying out ultrasonic treatment, adding a nitric acid solution, continuing the ultrasonic treatment, filtering, washing with water, and drying to obtain a pretreated carbon nanotube; sending the pretreated carbon nano tube into a torque rheometer, continuously adding polylactic acid and beta-cyclodextrin, cooling and crushing after heat treatment, and spinning by adopting an electrostatic spinning method to obtain modified carbon nano fiber; uniformly stirring polypropylene, sodium alginate, chitosan, sodium starch octenyl succinate, yttrium oxide and a dispersing agent to obtain a premix; and melting and extruding the premix, the modified carbon nanofiber and the glass fiber, conveying the obtained melt into a spinning assembly after sequentially passing through a filter and a metering pump, spraying out the melt through a spinneret orifice, performing air cooling at a position 12-15cm away from a spinneret plate, drawing, dropping the drawn melt onto a web forming curtain through filament separation, paving the web forming curtain into a fiber net, reinforcing the fiber net by a hot pressing roller, and performing hot polishing to obtain the high-toughness carbon nanofiber reinforced non-woven fabric.)

1. A preparation method of a high-toughness carbon nanofiber reinforced non-woven fabric is characterized by comprising the following steps:

a. mixing the multi-walled carbon nano-tube with hydrochloric acid, carrying out ultrasonic treatment for 1-2h with the ultrasonic power of 500-560W, adding a nitric acid solution, continuing ultrasonic treatment for 15-30min, filtering, washing with water, and drying to obtain a pretreated carbon nano-tube;

b. sending the pretreated carbon nano tube into a torque rheometer, continuously adding polylactic acid and beta-cyclodextrin, treating at the temperature of 200 ℃ and 240 ℃ for 2-5min, adjusting the temperature to 140 ℃ and 160 ℃ and preserving the heat for 2-4h, cooling, crushing and carrying out electrostatic spinning to obtain modified carbon nano fiber;

c. uniformly stirring polypropylene, sodium alginate, chitosan, sodium starch octenyl succinate, yttrium oxide and a dispersing agent at 70-80 ℃ to obtain a premix;

d. and melting and extruding the premix, the modified carbon nanofiber and the glass fiber, conveying the obtained melt into a spinning assembly after sequentially passing through a filter and a metering pump, spraying out the melt through a spinneret orifice, carrying out air cooling at a position 12-15cm away from a spinneret plate, wherein the air temperature is 10-14 ℃, the air speed is 0.3-0.6m/s, falling onto a web forming curtain after drafting through yarn separation, paving into a fiber web, reinforcing by a hot pressing roller, and scalding to obtain the high-toughness carbon nanofiber reinforced non-woven fabric.

2. The method for preparing the high-toughness carbon nanofiber-reinforced non-woven fabric according to claim 1, wherein in the step a, the concentration of hydrochloric acid is 5.2-6mol/L, and the mass fraction of a nitric acid solution is 50-55%.

3. The method for preparing the high-toughness carbon nanofiber reinforced nonwoven fabric as claimed in claim 2, wherein in the step a, the mass ratio of the multi-walled carbon nanotubes to the hydrochloric acid to the nitric acid solution is 5-8: 20-30: 5-15.

4. The preparation method of the high-toughness carbon nanofiber reinforced non-woven fabric according to claim 1, wherein in the step b, the mass ratio of the pretreated carbon nanotubes to the polylactic acid to the beta-cyclodextrin is 10-14: 30-50: 2-6.

5. The method for preparing the high-toughness carbon nanofiber-reinforced non-woven fabric according to claim 1, wherein in the electrostatic spinning process in the step b, the voltage is 12-14kV, the distance is 6-8cm, and the extrusion speed of the spinning solution is 0.1-0.12 mL/h.

6. The preparation method of the high-toughness carbon nanofiber reinforced non-woven fabric as claimed in claim 1, wherein in the step c, the mass ratio of polypropylene, sodium alginate, chitosan, sodium starch octenyl succinate, yttrium oxide and a dispersing agent is 30-50: 15-30: 6-10: 2-4: 0.2-0.6: 0.5-1.2.

7. The preparation method of the high-toughness carbon nanofiber reinforced non-woven fabric according to claim 1, wherein in the step d, the mass ratio of the premix to the modified carbon nanofiber to the glass fiber is 100: 2-4: 1-3.

8. The method for preparing the high-toughness carbon nanofiber-reinforced nonwoven fabric as claimed in claim 1, wherein the grammage of the high-toughness carbon nanofiber-reinforced nonwoven fabric obtained in step d is 6-6.8g/m²。

9. A high-toughness carbon nanofiber-reinforced nonwoven fabric produced by the method for producing a high-toughness carbon nanofiber-reinforced nonwoven fabric according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of non-woven fabrics, in particular to a high-toughness carbon nanofiber reinforced non-woven fabric and a preparation method thereof.

Background

According to the statistical data of the China Association for industrial textile industries, in the production of nonwoven fabrics in China, the consumption of polypropylene slices accounts for about 90 percent, and the consumption of PET slices only accounts for less than 7 percent. The polypropylene is used as the main raw material of the non-woven fabric, does not need to be dried before melt spinning, has low price and has great technical and economic advantages. However, polypropylene linear saturated hydrocarbons are difficult to degrade by microorganisms when buried, and thus, they put a great pressure on environmental protection. Along with the social and economic development and the improvement of living standard, the requirements of people on environmental protection are higher and higher, the 'white pollution' caused by the traditional plastics is emphasized by people, and the life of people is gradually enriched by the material represented by the degradable non-woven fabric.

With the development of non-woven fabric technology and the requirement of further improving the performance of non-woven fabric products, the composite non-woven fabric and related products are developed quickly, and the application of the non-woven fabric can be expanded to a plurality of untouched fields through different composite finishing processing, so that the performance of the non-woven fabric is greatly improved. However, compared with woven fabrics, the conventional degradable non-woven fabrics have poor toughness, so that the non-woven fabrics have poor recycling performance and poor bearing performance, and the application range of the conventional non-woven fabrics is not wide enough, especially the non-woven fabrics in the field of high toughness.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a high-toughness carbon nanofiber reinforced non-woven fabric and a preparation method thereof.

A preparation method of a high-toughness carbon nanofiber reinforced non-woven fabric comprises the following steps:

a. mixing the multi-walled carbon nano-tube with hydrochloric acid, carrying out ultrasonic treatment for 1-2h with the ultrasonic power of 500-560W, adding a nitric acid solution, continuing ultrasonic treatment for 15-30min, filtering, washing with water, and drying to obtain a pretreated carbon nano-tube;

b. sending the pretreated carbon nano tube into a torque rheometer, continuously adding polylactic acid and beta-cyclodextrin, treating at the temperature of 200 ℃ and 240 ℃ for 2-5min, adjusting the temperature to 140 ℃ and 160 ℃ and preserving the heat for 2-4h, cooling, crushing and carrying out electrostatic spinning to obtain modified carbon nano fiber;

c. uniformly stirring polypropylene, sodium alginate, chitosan, sodium starch octenyl succinate, yttrium oxide and a dispersing agent at 70-80 ℃ to obtain a premix;

d. and melting and extruding the premix, the modified carbon nanofiber and the glass fiber, conveying the obtained melt into a spinning assembly after sequentially passing through a filter and a metering pump, spraying out the melt through a spinneret orifice, carrying out air cooling at a position 12-15cm away from a spinneret plate, wherein the air temperature is 10-14 ℃, the air speed is 0.3-0.6m/s, falling onto a web forming curtain after drafting through yarn separation, paving into a fiber web, reinforcing by a hot pressing roller, and scalding to obtain the high-toughness carbon nanofiber reinforced non-woven fabric.

Preferably, in the step a, the concentration of the hydrochloric acid is 5.2-6mol/L, and the mass fraction of the nitric acid solution is 50-55%.

Preferably, in the step a, the mass ratio of the multi-wall carbon nanotubes to the hydrochloric acid to the nitric acid solution is 5-8: 20-30: 5-15.

Preferably, in the step b, the mass ratio of the pretreated carbon nanotubes to the polylactic acid to the beta-cyclodextrin is 10-14: 30-50: 2-6.

Preferably, in the electrostatic spinning process of the step b, the voltage is 12-14kV, the distance is 6-8cm, and the extrusion speed of the spinning solution is 0.1-0.12 mL/h.

Preferably, in the step c, the mass ratio of the polypropylene, the sodium alginate, the chitosan, the sodium starch octenyl succinate, the yttrium oxide and the dispersing agent is 30-50: 15-30: 6-10: 2-4: 0.2-0.6: 0.5-1.2.

Preferably, in the step d, the mass ratio of the premix, the modified carbon nanofibers and the glass fibers is 100: 2-4: 1-3.

Preferably, in the step d, the gram weight of the obtained high-toughness carbon nanofiber reinforced non-woven fabric is 6-6.8g/m²。

A high-toughness carbon nanofiber reinforced non-woven fabric is prepared by adopting the preparation method of the high-toughness carbon nanofiber reinforced non-woven fabric.

The technical effects of the invention are as follows:

according to the invention, the modified carbon nanofibers are added in the production process of the non-woven fabric, so that the non-woven fabric has elasticity and bulkiness, is degradable and can effectively reduce the gram weight of the non-woven fabric, and the modified carbon nanofibers are compounded with the glass fibers, so that the non-woven fabric has excellent toughness and mechanical properties on the premise of ensuring low gram weight of the non-woven fabric.

In the step a, after the multiwall carbon nanotube is subjected to moderate acidification pretreatment by hydrochloric acid, the multiwall carbon nanotube can be uniformly oxidized on the surface of the multiwall carbon nanotube in a mixed solution of nitric acid and hydrochloric acid, so that rich oxygen-containing functional groups are formed; then in the step b, the polymer is combined with polylactic acid and beta-cyclodextrin, the mutual dispersibility is good, agglomeration is not easy to form, and after the introduced high polymer matrix is spun, the matrix of the pretreated carbon nano tube reacts with the polymer coated outside to form a nano-scale polymer interface; in the step d, the modified carbon nanofiber is combined with polypropylene and sodium alginate, so that the toughening effect of the modified carbon nanofiber is fully exerted, and researches show that when the mass ratio of the premix to the modified carbon nanofiber reaches 100: 2-4, the toughness of the reinforced non-woven fabric is best, when the ratio is more than the ratio, the modified carbon nano-fiber has poor mixing and mixing properties and fiber falling phenomena, and when the ratio is less than the ratio, the high-strength toughening effect cannot be achieved.

The non-woven fabric prepared by the method disclosed by the invention has higher strength and toughness compared with a composite material toughened by a polymer, and is simple in preparation process and more convenient to popularize and apply.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.

Example 1

A preparation method of a high-toughness carbon nanofiber reinforced non-woven fabric comprises the following steps:

a. mixing 5kg of multi-walled carbon nano-tube and 30kg of hydrochloric acid with the concentration of 5.2mol/L, carrying out ultrasonic treatment for 2 hours at the ultrasonic power of 500W, adding 15kg of nitric acid solution with the mass fraction of 50%, continuing ultrasonic treatment for 30min, filtering, washing for 2 times, and drying to obtain a pretreated carbon nano-tube;

b. sending 14kg of pretreated carbon nano tube into a torque rheometer, continuously adding 30kg of polylactic acid and 6kg of beta-cyclodextrin, treating for 5min at 200 ℃, wherein the rotating speed is controlled to be 40r/min, adjusting the temperature to 160 ℃, preserving the heat for 2h, cooling, crushing and carrying out electrostatic spinning to obtain modified carbon nano fiber;

in the electrostatic spinning process, the voltage is 14kV, the distance is 6cm, and the extrusion speed of the spinning solution is 0.12 mL/h;

c. feeding 30kg of polypropylene, 30kg of sodium alginate, 6kg of chitosan, 4kg of sodium starch octenylsuccinate, 0.2kg of yttrium oxide and 1.2kg of dispersing agent into a high-speed stirrer, and stirring at the speed of 1200r/min for 10min at the stirring temperature of 70 ℃ to obtain a premix;

d. feeding 100kg of premix, 4kg of modified carbon nanofiber and 1kg of glass fiber into a screw extruder for melt extrusion, wherein the rotating speed of a screw is 60r/min, sequentially passing the obtained melt through a filter and a metering pump, conveying the melt into a spinning assembly, spraying the melt through a spinneret orifice, performing air cooling at a position 12cm away from a spinneret plate, the air temperature is 14 ℃, the air speed is 0.3m/s, drawing, dropping the melt onto a web forming curtain through dividing filaments, paving the web, reinforcing the web by a hot pressing roller, and performing hot polishing to obtain a web with the gram weight of 6.8g/m²The high-toughness carbon nanofiber reinforced non-woven fabric.

Example 2

A preparation method of a high-toughness carbon nanofiber reinforced non-woven fabric comprises the following steps:

a. mixing 8kg of multi-walled carbon nano-tube with 20kg of hydrochloric acid with the concentration of 6mol/L, carrying out ultrasonic treatment for 1h, adding 5kg of nitric acid solution with the mass fraction of 55%, continuing ultrasonic treatment for 15min, filtering, washing for 4 times, and drying to obtain a pretreated carbon nano-tube;

b. sending 10kg of pretreated carbon nano tube into a torque rheometer, continuously adding 50kg of polylactic acid and 2kg of beta-cyclodextrin, treating for 2min at 240 ℃, controlling the rotating speed to be 60r/min, adjusting the temperature to 140 ℃, preserving the heat for 4h, cooling, crushing and carrying out electrostatic spinning to obtain modified carbon nano fiber;

in the electrostatic spinning process, the voltage is 12kV, the distance is 8cm, and the extrusion speed of the spinning solution is 0.1 mL/h;

c. feeding 50kg of polypropylene, 15kg of sodium alginate, 10kg of chitosan, 2kg of sodium starch octenyl succinate, 0.6kg of yttrium oxide and 0.5kg of dispersing agent into a high-speed stirrer, and stirring at the speed of 2000r/min for 5min at the stirring temperature of 80 ℃ to obtain a premix;

d. feeding 100kg of premix, 2kg of modified carbon nanofiber and 3kg of glass fiber into a screw extruder for melt extrusion, wherein the rotating speed of a screw is 45r/min, sequentially passing the obtained melt through a filter and a metering pump, conveying the melt into a spinning assembly, spraying the melt through a spinneret orifice, performing air cooling at a position 15cm away from a spinneret plate, the air temperature is 10 ℃, the air speed is 0.6m/s, drawing, dropping the melt onto a web forming curtain through dividing filaments, paving the web, reinforcing the web by a hot pressing roller, and performing hot polishing to obtain a web with the gram weight of 6g/m²The high-toughness carbon nanofiber reinforced non-woven fabric.

Example 3

A preparation method of a high-toughness carbon nanofiber reinforced non-woven fabric comprises the following steps:

a. mixing 6kg of multi-walled carbon nano-tube and 28kg of hydrochloric acid with the concentration of 5.4mol/L, carrying out ultrasonic treatment for 1.8h, wherein the ultrasonic power is 520W, adding 12kg of nitric acid solution with the mass fraction of 52%, continuing ultrasonic treatment for 25min, filtering, washing for 3 times, and drying to obtain a pretreated carbon nano-tube;

b. sending 11kg of pretreated carbon nano tube into a torque rheometer, continuously adding 45kg of polylactic acid and 3kg of beta-cyclodextrin, treating at 230 ℃ for 3min, controlling the rotating speed to be 55r/min, adjusting the temperature to 145 ℃, keeping the temperature for 3.5h, cooling, crushing and carrying out electrostatic spinning to obtain modified carbon nano fiber;

in the electrostatic spinning process, the voltage is 12.5kV, the distance is 7.5cm, and the extrusion speed of the spinning solution is 0.105 mL/h;

c. feeding 45kg of polypropylene, 20kg of sodium alginate, 9kg of chitosan, 2.5kg of sodium starch octenylsuccinate, 0.5kg of yttrium oxide and 0.6kg of dispersing agent into a high-speed stirrer, and stirring at 1800r/min for 6min at the stirring temperature of 78 ℃ to obtain a premix;

d. feeding 100kg of premix, 2.5kg of modified carbon nanofiber and 2.5kg of glass fiber into a screw extruder for melt extrusion, wherein the rotating speed of a screw is 50r/min, sequentially passing the obtained melt through a filter and a metering pump, conveying the melt into a spinning assembly, spraying the melt through a spinneret orifice, performing air cooling at a position 14cm away from a spinneret plate, wherein the air temperature is 11 ℃, the air speed is 0.5m/s, drawing, separating filaments, dropping on a web forming curtain, paving into a fiber web, reinforcing by a hot pressing roller, and performing hot polishing to obtain the fiber web with the gram weight of 6.2g/m²The high-toughness carbon nanofiber reinforced non-woven fabric.

Example 4

A preparation method of a high-toughness carbon nanofiber reinforced non-woven fabric comprises the following steps:

a. mixing 7kg of multi-walled carbon nano-tube with 22kg of hydrochloric acid with the concentration of 5.8mol/L, carrying out ultrasonic treatment for 1.2h with the ultrasonic power of 540W, adding 8kg of nitric acid solution with the mass fraction of 54%, continuing ultrasonic treatment for 20min, filtering, washing for 3 times, and drying to obtain a pretreated carbon nano-tube;

b. sending 13kg of pretreated carbon nano tube into a torque rheometer, continuously adding 35kg of polylactic acid and 5kg of beta-cyclodextrin, treating at 210 ℃ for 4min, controlling the rotating speed at 45r/min, adjusting the temperature to 155 ℃, keeping the temperature for 2.5h, cooling, crushing and carrying out electrostatic spinning to obtain modified carbon nano fiber;

in the electrostatic spinning process, the voltage is 13.5kV, the distance is 6.5cm, and the extrusion speed of the spinning solution is 0.115 mL/h;

c. feeding 35kg of polypropylene, 25kg of sodium alginate, 7kg of chitosan, 3.5kg of sodium starch octenylsuccinate, 0.3kg of yttrium oxide and 1kg of dispersing agent into a high-speed stirrer, and stirring at 1400r/min for 8min at the stirring temperature of 72 ℃ to obtain a premix;

d. feeding 100kg of premix, 3.5kg of modified carbon nanofiber and 1.5kg of glass fiber into a screw extruder for melt extrusion, wherein the rotating speed of a screw is 55r/min, conveying the obtained melt into a spinning assembly through a filter and a metering pump in sequence, spraying out through a spinneret orifice, performing air cooling at a position 13cm away from a spinneret plate, wherein the air temperature is 13 ℃, the air speed is 0.4m/s, falling onto a web forming curtain through yarn splitting after drafting, laying into a fiber net, reinforcing by a hot pressing roller,the tarnish is carried out to obtain the gram weight of 6.6g/m²The high-toughness carbon nanofiber reinforced non-woven fabric.

Example 5

A preparation method of a high-toughness carbon nanofiber reinforced non-woven fabric comprises the following steps:

a. mixing 6.5kg of multi-walled carbon nano-tube with 25kg of hydrochloric acid with the concentration of 5.6mol/L, carrying out ultrasonic treatment for 1.5h with the ultrasonic power of 530W, adding 10kg of nitric acid solution with the mass fraction of 53%, continuing ultrasonic treatment for 22min, filtering, washing for 3 times, and drying to obtain a pretreated carbon nano-tube;

b. sending 12kg of pretreated carbon nano tube into a torque rheometer, continuously adding 40kg of polylactic acid and 4kg of beta-cyclodextrin, treating at 220 ℃ for 3.5min, controlling the rotating speed at 50r/min, adjusting the temperature to 150 ℃, preserving the heat for 3h, cooling, crushing and carrying out electrostatic spinning to obtain modified carbon nano fiber;

in the electrostatic spinning process, the voltage is 13kV, the distance is 7cm, and the extrusion speed of the spinning solution is 0.11 mL/h;

c. feeding 40kg of polypropylene, 23kg of sodium alginate, 8kg of chitosan, 3kg of sodium starch octenyl succinate, 0.4kg of yttrium oxide and 0.8kg of dispersing agent into a high-speed stirrer, and stirring at 1600r/min for 7min at 75 ℃ to obtain a premix;

d. feeding 100kg of premix, 3kg of modified carbon nanofiber and 2kg of glass fiber into a screw extruder for melt extrusion, wherein the rotating speed of a screw is 53r/min, sequentially passing the obtained melt through a filter and a metering pump, conveying the melt into a spinning assembly, spraying the melt through a spinneret orifice, performing air cooling at a position 13.5cm away from a spinneret plate, the air temperature is 12 ℃, the air speed is 0.45m/s, drawing, separating filaments, dropping on a web forming curtain, paving a fiber web, reinforcing by a hot pressing roller, and performing hot ironing to obtain the fiber web with the gram weight of 6.4g/m²The high-toughness carbon nanofiber reinforced non-woven fabric.

Comparative example 1

A preparation method of a high-toughness non-woven fabric comprises the following steps:

s1, feeding 40kg of polypropylene, 23kg of sodium alginate, 8kg of chitosan, 3kg of sodium starch octenyl succinate, 0.4kg of yttrium oxide and 0.8kg of dispersing agent into a high-speed stirrer, and stirring at 1600r/min for 7min at 75 ℃ to obtain a premix;

s2, feeding 100kg of premix, 3kg of carbon nanofiber and 2kg of glass fiber into a screw extruder for melt extrusion, wherein the rotating speed of a screw is 53r/min, conveying the obtained melt into a spinning assembly through a filter and a metering pump in sequence, spraying out through a spinneret orifice, performing air cooling at a position 13.5cm away from a spinneret plate, wherein the air temperature is 12 ℃, the air speed is 0.45m/S, dropping on a web forming curtain through dividing filaments after drafting to form a fiber web, reinforcing by a hot pressing roller, and ironing and polishing the high-toughness non-woven fabric.

Comparative example 2

A preparation method of a high-toughness non-woven fabric comprises the following steps:

s1, feeding 40kg of polypropylene, 23kg of sodium alginate, 8kg of chitosan, 3kg of sodium starch octenyl succinate, 0.4kg of yttrium oxide and 0.8kg of dispersing agent into a high-speed stirrer, and stirring at 1600r/min for 7min at 75 ℃ to obtain a premix;

s2, feeding 100kg of premix, 3kg of multi-walled carbon nanotubes and 2kg of glass fibers into a screw extruder for melt extrusion, wherein the rotating speed of the screw is 53r/min, conveying the obtained melt into a spinning assembly through a filter and a metering pump in sequence, spraying out through a spinneret orifice, performing air cooling at a position 13.5cm away from a spinneret plate, wherein the air temperature is 12 ℃, the air speed is 0.45m/S, dropping on a web forming curtain through dividing filaments after drafting to form a fiber web, reinforcing by a hot pressing roller, and ironing and polishing the high-toughness non-woven fabric.

Comparative example 3

A preparation method of a high-toughness non-woven fabric comprises the following steps:

s1, feeding 40kg of polypropylene, 23kg of sodium alginate, 8kg of chitosan, 3kg of sodium starch octenyl succinate, 0.4kg of yttrium oxide and 0.8kg of dispersing agent into a high-speed stirrer, and stirring at 1600r/min for 7min at 75 ℃ to obtain a premix;

s2, feeding 100kg of premix, 3kg of polylactic acid and 2kg of glass fiber into a screw extruder for melt extrusion, wherein the rotating speed of a screw is 53r/min, conveying the obtained melt into a spinning assembly through a filter and a metering pump in sequence, spraying out through a spinneret orifice, performing air cooling at a position 13.5cm away from a spinneret plate, wherein the air temperature is 12 ℃, the air speed is 0.45m/S, dropping on a web forming curtain through dividing filaments after drafting to form a fiber web, reinforcing by a hot press roller, and ironing and polishing the high-toughness non-woven fabric.

Comparative example 4

A preparation method of a high-toughness non-woven fabric comprises the following steps:

s1, mixing 6.5kg of multi-walled carbon nanotubes with 25kg of hydrochloric acid with the concentration of 5.6mol/L, carrying out ultrasonic treatment for 1.5h at the ultrasonic power of 530W, adding 10kg of nitric acid solution with the mass fraction of 53%, continuing ultrasonic treatment for 22min, filtering, washing with water for 3 times, and drying to obtain pretreated carbon nanotubes;

s2, feeding 12kg of pretreated carbon nano tube into a torque rheometer, continuously adding 40kg of polylactic acid and 4kg of beta-cyclodextrin, treating at 220 ℃ for 3.5min, wherein the rotating speed is controlled to be 50r/min, adjusting the temperature to 150 ℃, preserving the heat for 3h, cooling, crushing and carrying out electrostatic spinning to obtain modified carbon nano fiber;

in the electrostatic spinning process, the voltage is 13kV, the distance is 7cm, and the extrusion speed of the spinning solution is 0.11 mL/h;

s3, feeding 40kg of polypropylene, 23kg of sodium alginate, 8kg of chitosan, 3kg of sodium starch octenyl succinate, 0.4kg of yttrium oxide and 0.8kg of dispersing agent into a high-speed stirrer, and stirring at 1600r/min for 7min at 75 ℃ to obtain a premix;

s4, feeding 100kg of premix, 6kg of modified carbon nanofiber and 2kg of glass fiber into a screw extruder for melt extrusion, wherein the rotating speed of the screw is 53r/min, conveying the obtained melt into a spinning assembly through a filter and a metering pump in sequence, spraying out through a spinneret orifice, performing air cooling at a position 13.5cm away from a spinneret plate, wherein the air temperature is 12 ℃, the air speed is 0.45m/S, dropping on a web forming curtain through dividing filaments after drafting to form a fiber web, reinforcing by a hot pressing roller, and ironing and polishing the high-toughness non-woven fabric.

The nonwoven fabrics obtained in example 5 and comparative examples 1 to 4 were subjected to mechanical property tests, and the results were as follows:

	example 5	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4
						Gram weight, g/m2	6.4	8.7	8.3	7.5	7.9
Porosity%	86.13	77.93	78.54	71.72	80.26
						Breaking strength, Mpa	1.5	1.3	1.2	0.5	0.8
Elongation at break,%	6.4	5.6	5.0	3.5	3.2

Wherein, the breaking strength and the breaking elongation are tested by a YG (B)026H type electronic fabric strength tester according to GB/T3923.1-2013.

From the above table, it can be seen that: according to the invention, the modified carbon nanofibers are added in the production process of the non-woven fabric, the modified carbon nanofibers can play a role of a framework, so that the non-woven fabric has elasticity and bulkiness, the gram weight of the non-woven fabric is effectively reduced, and the modified carbon nanofibers are compounded with the glass fibers, so that the non-woven fabric has excellent toughness and excellent mechanical properties on the premise of ensuring low gram weight.

The nonwovens obtained in example 5 and comparative examples 1 to 4 were subjected to a toughness test, the tensile strength being measured first using a tensile tester (Instron 4467) according to the test method of ASTM D4632. At this time, conditions of a load cell (load cell) of 500kgf and an elongation rate of 50mm/min were applied, and then the tear strength and the work at break were measured according to the test method of ASTM D2261 using the same parameters as described above.

The results are as follows:

from the above table, it can be seen that: the non-woven fabric obtained in the embodiment 5 has excellent tensile strength and tear strength, because the modified carbon nanofiber is added in the production process of the non-woven fabric, the non-woven fabric obtained in the invention can play a role of a framework by virtue of the modified carbon nanofiber, and the non-woven fabric is reinforced, meanwhile, the modified carbon nanofiber takes the pretreated carbon nanotube as a matrix and forms a nano-scale polymer interface with polylactic acid and beta-cyclodextrin, and the polylactic acid and the beta-cyclodextrin have high compatibility with polypropylene and sodium alginate, so that the toughening effect of the modified carbon nanofiber is fully exerted.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.