Bio-based modified melt-blown material, bio-based melt-blown cloth and preparation method and application of bio-based modified melt-blown material

Abstract

The invention provides a bio-based modified melt-blown material, bio-based melt-blown cloth as well as a preparation method and application of the bio-based modified melt-blown material. Polylactic acid and poly (butylene succinate-adipate) are used as main materials, a compatilizer is added to promote blending compatibility of the two biopolymer materials, the mechanical property of the material is improved, and meanwhile, a nucleating agent is added to improve the heat-resistant temperature of the material through the dual effects of oriented crystallization and fixed molecular chain movement of the two biopolymer materials. Besides, the bio-based modified melt-blown material can be processed into a melt-blown cloth product on universal melt-blown molding equipment, the use temperature of the product is-25-105 DEG C or above, the performance is excellent, the 38-day biodegradation rate is larger than 99%, the 48-day degradation rate of uric acid is larger than 99%, and the bio-based modified melt-blown material has practical popularization value.

Description

Technical Field

[0001] The present invention belongs to the technical field of meltblown cloth, and specifically relates to a bio-based modified meltblown material, a bio-based meltblown cloth, and a preparation method and application thereof. Background Art

[0002] The advent and rapid development of synthetic polymers in the 20th century have permeated every aspect of the national economy and people's lives, making them one of the four pillars of materials, alongside steel, wood, and cement. However, this massive production and consumption of synthetic polymers has also created two major problems: over-reliance on non-renewable oil and coal resources, which has accelerated the depletion of limited resources. Furthermore, the inability of these polymers to naturally degrade has led to the creation of "permanent" plastic waste. Faced with the challenge of dealing with plastic waste and reducing over-reliance on oil and coal, three primary approaches have been adopted: incineration for thermal energy, recycling, and natural degradation. Second, my country discards over 20 million tons of disposable products annually after use, including those that are not suitable or difficult to recycle. Nearly 50% of this waste is not recycled, and of that 50%, approximately 20% is not properly disposed of and enters the natural environment. Despite strict waste sorting and plastic restrictions in some industries, difficult-to-recycle single-use plastic waste (such as disposable masks for epidemic prevention, disposable dry and wet napkins for food, and disposable facial masks for beauty salons) is forced to be incinerated or landfilled. Incineration releases large amounts of carbon dioxide, creating a greenhouse effect that disrupts the ecological balance. To purify the environment and eliminate plastic waste, sanitary landfills are often used. While sanitary landfills can significantly alleviate environmental pollution, they also pass the burden of environmental damage on to the next generation. While disposable food and daily necessities are biodegradable, the wood pulp fibers used in their initial production generate significant wastewater, polluting water sources. To meet water quality standards, wastewater treatment plants must be constructed. Therefore, biodegradable (biodegradable) polymer materials can be used for disposable products. Even if they are left in the environment, they can be completely degraded by microorganisms into carbon dioxide and water, which are harmless to the environment.

[0003] Entering the 21st century, many countries have made the construction of a sustainable resource-circulating society one of their national policies and have vigorously developed environmentally friendly biodegradable polymer materials. Bio-based and modified polymer materials have become an industry hotspot, showing a strong development momentum. Summary of the Invention

[0004] The present invention provides a bio-based modified meltblown material, which is a biodegradable composite and modified polymer material. The meltblown cloth produced by the material has excellent heat resistance, toughness, softness, and good water absorption. Polylactic acid (PLA) polymer material is in a glassy state at room temperature. It has the highest rigidity among biodegradable polymer materials, but its heat resistance, toughness, and softness are relatively poor. Its heat deformation temperature (under a load of 0.45MPa) is only 55°C, and its notched impact is 2.3 (KJ / m 2 To meet the process requirements for producing meltblown fabrics from biodegradable materials, the toughness, softness, and heat resistance of PLA must be improved, and the melt flow rate (MFR) of the biodegradable material must also be significantly increased. The present invention provides a bio-based modified meltblown material with a high melt flow rate, which can be used in, but not limited to, medical supplies such as disposable medical masks, disposable medical cotton balls, disposable paper towels, and beauty masks, as well as daily necessities.

[0005] One of the purposes of the present invention is to provide a bio-based modified meltblown material, comprising: a mixture of polylactic acid (PLA), polybutylene succinate-adipate (PBSA), a nucleating agent, a compatibilizer and / or a reaction product thereof.

[0006] In the bio-based modified melt-blown material provided by the present invention:

[0007] The weight average molecular weight (Mw) of the polylactic acid is 250,000 to 300,000, preferably 250,000 to 260,000;

[0008] The melt flow rate (MFR) of the polylactic acid is 25 to 32 g / 10 min, preferably 28 to 30 g / 10 min;

[0009] The weight average molecular weight (Mw) of the polybutylene succinate-adipate ester is 227,000 to 235,000, preferably 227,000 to 230,000;

[0010] The melt flow rate (MFR) of the polybutylene succinate-adipate ester is 20 to 30 g / 10 min, preferably 25 to 28 g / 10 min;

[0011] The nucleating agent is an organic nucleating agent, preferably bis(3,4-dimethylbenzylidene) sorbitol, and specifically commercially available nucleating agent 3988 or SKC-Y3988 can be used;

[0012] The compatibilizer is selected from graft copolymers of aliphatic dibasic acid / aliphatic diol copolyesters and glycidyl methacrylate, preferably at least one selected from graft copolymers of poly(butylene succinate-adipate-butylene glycol) and glycidyl methacrylate (PBSA-g-GMA), graft copolymers of poly(butylene succinate) and glycidyl methacrylate (PBS-g-GMA);

[0013] The bio-based modified meltblown material further comprises at least one of an antioxidant, a lubricant, a heat stabilizer, and a dispersant. Among them, the antioxidant is selected from phosphite antioxidants, preferably at least one selected from tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), tris(nonylphenyl) phosphite; the lubricant is selected from at least one of pentaerythritol stearate (PETS), erucamide; the heat stabilizer is selected from at least one of calcium stearate, sodium stearate; the dispersant is selected from polyolefin wax (PO), preferably, the polyolefin wax is selected from at least one of polyethylene wax (PE wax), polypropylene wax (PP wax), and the number-average molecular weight of the polyolefin wax is 1500-1700.

[0014] In the bio-based modified meltblown material provided by the present invention:

[0015] Calculated based on the total weight percentage of the bio-based modified meltblown material being 100%, the polylactic acid is 30-70%, the poly(butylene succinate-adipate-butylene glycol) is 25-70%, the nucleating agent is 0.1-0.8%, the compatibilizer is 0.5-5%, the antioxidant is 0.01-0.5%, the lubricant is 0.1-2%, the heat stabilizer is 0.1-2%, and the dispersant is 3-15%;

[0016] Preferably, calculated based on the total weight percentage of the bio-based modified meltblown material being 100%, the polylactic acid is 40-50%, the poly(butylene succinate-adipate-butylene glycol) is 35-50%, the nucleating agent is 0.2-0.5%, the compatibilizer is 1.5-3%, the antioxidant is 0.1-0.2%, the lubricant is 0.5-1%, the heat stabilizer is 0.5-1%, and the dispersant is 6-10%.

[0017] In the bio-based modified meltblown material provided by the present invention, the nucleating agent has a high nucleating effect, which can improve the crystallization rate, change the spherulite crystal form, reduce the crystal size, and endow the crystalline biodegradable polymer material with obvious thermal stability and impact resistance; the compatibilizer enables two incompatible biodegradable polymer resins (PLA and PBSA) to be combined together by the intermolecular bonding force, thereby forming a polymer blend modified by a miscible system; the antioxidant can effectively prevent the yellowing phenomenon during processing; the lubricant is used as an efficient lubricant in the formulation and can also have a nucleating effect on the biological crystalline material; the heat stabilizer can improve the internal lubrication and demolding effect of the biodegradable polymer material; the dispersant has good internal (20%) and external (80%) lubrication effects, and has good thermal stability, chemical stability and electrical stability, is non-toxic and non-corrosive, and preferably has a low molecular weight wax (Mn is 1500-1700), which will not affect the decomposition of the biodegradable polymer material.

[0018] The second object of the present invention is to provide a preparation method of the above-mentioned bio-based modified meltblown material, including: premixing components including the above-mentioned polylactic acid, poly(butylene succinate-adipate-butylene glycol), nucleating agent, and compatibilizer, and then melt-extruding to obtain the bio-based modified meltblown material.

[0019] In the preparation method of the above-mentioned bio-based modified meltblown material:

[0020] The above-mentioned polylactic acid and poly(butylene succinate-adipate-butylene glycol) do not need to be dried, and their melt index can be improved by using their hydrolyzability during the preparation process; preferably, the water content of the polylactic acid is 1000-1500 ppm; the water content of the poly(butylene succinate-adipate-butylene glycol) is 1500-2000 ppm;

[0021] At least one of an antioxidant, a lubricant, a heat stabilizer, and a dispersant is further added during the premixing process; wherein, the antioxidant is selected from phosphite antioxidants, preferably at least one of tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168) and tris(nonylphenyl) phosphite; the lubricant is selected from at least one of pentaerythritol stearate (PETS) and erucamide; the heat stabilizer is selected from at least one of calcium stearate and sodium stearate; the dispersant is selected from polyolefin waxes (PO), preferably, the polyolefin wax is selected from at least one of polyethylene wax (PE wax) and polypropylene wax (PP wax), and the number average molecular weight of the polyolefin wax is 1500-1700;

[0022] The premixing includes steps of high-speed stirring and low-speed stirring, wherein, the conditions of the high-speed stirring are: temperature 50-60 °C, rotation speed 1200-1500 rpm, time 1-3 minutes; the conditions of the low-speed stirring are: temperature 20-25 °C, rotation speed 300-500 rpm, time 3-5 minutes;

[0023] The melt extrusion is completed on a twin-screw extruder. Among them, the conditions of the twin-screw extruder are as follows: die head 200 - 220 °C, metering section 190 - 210 °C, plasticizing section 160 - 180 °C, material selection section 150 - 180 °C, and screw rotation speed 250 - 300 r / min. The material after melt extrusion can be pelletized by underwater strand cutting. After pelletizing, it is dried at a temperature above 80 °C for more than 2 hours, and then discharged for packaging.

[0024] The third object of the present invention is to provide a bio-based modified meltblown material as described above or a bio-based modified meltblown material obtained by the above preparation method. The melt index of the bio-based modified meltblown material is 1200 - 1400 g / 10 min.

[0025] The fourth object of the present invention is to provide a bio-based meltblown cloth, which is prepared by processing the above bio-based modified meltblown material through a meltblowing device.

[0026] Among them, the meltblowing device and meltblowing conditions used can both adopt the commonly used devices and process conditions in the art. The specific meltblowing process includes: the above bio-based modified meltblown material enters the hopper of the meltblowing machine, and at a preset forming temperature, it is extruded from the die head through a filter screen under the screw metering pump speed, and high-pressure hot air is evenly sprayed onto a rotatable mesh belt, and after electrostatic treatment, it is thermally wound into a meltblown cloth. Among them, the meltblowing operating conditions are as follows: meltblowing extrusion temperature: zone 1 temperature: 176 - 185 °C, zone 2 temperature: 200 - 215 °C, zone 3 temperature: 220 - 230 °C, zone 4 temperature: 220 - 230 °C; filter screen temperature: 220 - 230 °C; screw rotation speed: 70 - 80 r / min; metering pump temperature: 220 - 230 °C; metering pump speed: 4 - 4.5 r / min; die head temperature: 220 - 230 °C; wire passing speed: 20 - 25 m / min; winding speed: 20 - 25 m / min; hot air pressure: 4 - 5 MPa.

[0027] A fifth object of the present invention is to provide an application of the above-mentioned bio-based modified meltblown material or the above-mentioned bio-based meltblown cloth in medical supplies and sanitary products. Preferably, the bio-based modified meltblown material or bio-based meltblown cloth is used to replace disposable masks, disposable wet and dry alcohol cotton balls for epidemic prevention and medical supplies, or to replace disposable wet and dry napkins in the catering industry, or to replace disposable facial masks in the beauty industry, or to replace disposable diaper absorbent backing cloth. Specifically, the bio-based modified meltblown material or bio-based meltblown cloth provided by the present invention can be applied to disposable medical masks, disposable medical cotton balls, disposable paper towels, beauty mask products, etc. It can manufacture disposable masks, disposable alcohol cotton balls and dry cotton balls that are difficult to recycle, and can also manufacture disposable dry and wet napkins, beauty masks, diapers, sanitary napkins, etc. that are difficult to recycle in the catering industry. It can not only replace plant cotton and wood pulp fiber paper, has excellent use performance, but also can be completely biodegradable, protecting the environment and reducing pollution.

[0028] The technical solution provided by the present invention has the following advantages:

[0029] 1) By using a PLA / PBSA composite added with a compatibilizer (a graft copolymer of aliphatic dibasic acid / aliphatic diol copolyester and glycidyl methacrylate), the toughness and flexibility problems of the composite modified material can be completely solved (compared with the polypropylene meltblown material in the prior art, the notch impact is increased by 5 times, and the flexural modulus is reduced by less than 1200 MPa);

[0030] 2) By using a nucleation technology, the added organic nucleating agent promotes the orientation crystallization of the biodegradable polymer material and fixes the molecular chain movement to improve the heat resistance temperature of the biodegradable polymer material, so that the Vicat heat distortion temperature reaches above 125 °C;

[0031] 3) By utilizing the hydrolyzability of the biodegradable polymer material and adding internal and external lubricating dispersants to comprehensively improve the flow rate of the modified material, so that the melt flow rate (MFR) reaches 1000 - 1400 g / 10 min, meeting the process requirements for producing biodegradable meltblown cloth;

[0032] 4) The bio-meltblown material can be processed into a meltblown cloth product on a general meltblown forming device. The product has a service temperature of -25 - 105 °C or above, excellent performance, a biodegradation rate of > 99% in 38 days, and a degradation rate of > 99% for uric acid degradation in 48 days, having practical promotion value;

[0033] 5) The prepared meltblown cloth can be used for disposable masks, beauty masks, disposable dry and wet napkins on the table, can replace general diapers and sanitary napkins, and the cut-off scraps can also be used for medical dry and wet cotton balls and hemostatic patches. Description of the Drawings

[0034] Figures 1 to 4 Test pictures of the soil burial degradation rate of the meltblown cloth 1# obtained in Example 1, where Figure 1 is the picture of the meltblown cloth 1# before the test, Figure 2 is the picture of the meltblown cloth 1# after being buried in the soil for 15 days, Figure 3 is the picture of the meltblown cloth 1# after being buried in the soil for 30 days, Figure 4 is the picture of the meltblown cloth 1# after being buried in the soil for 38 days. Specific implementation manners

[0035] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that the following embodiments are only used for further illustration of the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0036] The test standards adopted in the embodiments are as follows:

[0037]

[0038] If there is no special limitation on the raw materials used in the embodiments and comparative examples, they are all disclosed in the prior art. For example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0039] Example 1: Preparation of bio-based modified meltblown material A#

[0040] The formula of the bio-based modified meltblown material A# is as follows:

[0041] By weight percentage: PLA (Mw is 250000, melt flow rate is 30 g / 10 min, 190° / 2.16 kg, water content is 1051 ppm) 50%, PBSA (Mw is 227000, melt flow rate is 25 g / 10 min, 190° / 2.16 kg, water content is 1888 ppm) 35%, antioxidant (168) 0.15%, PETS 0.85%, calcium stearate (CaSt) 0.5%, nucleating agent (3988) 0.5%, PBSA-g-GMA 3%, PO wax (Mn is 1500 - 1700) 10%.

[0042] Preparation of the bio-based modified meltblown material A#:

[0043] Mix the above components according to the weight percentages. First, use a high-low speed stirring mixer to stir at a high speed of 1500 r / min at 60 °C for 1 minute, and then stir at a low speed of 500 r / min at 20 °C for 3 minutes. Feed the premixed material obtained by stirring into a twin-screw extruder. The conditions of the twin-screw extruder are: set the die head at 220 °C, the metering section at 210 °C, the plasticizing section at 205 °C, the feeding section at 180 °C, and the screw speed at 300 r / min. The material after melt extrusion is pelletized by underwater strand cutting. After pelletizing, dry it at a temperature above 80 °C for more than 2 hours, and then discharge and package to obtain the bio-based modified meltblown material A#.

[0044] Example 2: Preparation of bio-based modified meltblown material B#

[0045] The formula of bio-based modified meltblown material B# is as follows:

[0046] By weight percentage: PLA (same as in Example 1) 40%; PBSA (same as in Example 1) 50%; antioxidant (168) 0.1%; PETS 0.9%; CaSt 0.7%; nucleating agent (3988) 0.3%; PBSA-g-GMA 2%; PO wax (same as in Example 1) 6%.

[0047] Preparation of bio-based modified meltblown material B#:

[0048] Mix the above components according to the weight percentages. First, use a high-low speed stirring mixer to stir at a high speed of 1350 r / min at 50 °C for 2 minutes, and then stir at a low speed of 300 r / min at 20 °C for 4 minutes. Feed the premixed material obtained by stirring into a twin-screw extruder. The conditions of the twin-screw extruder are: set the die head at 200 °C, the metering section at 195 °C, the plasticizing section at 190 °C, the feeding section at 160 °C, and the screw speed at 260 r / min. The material after melt extrusion is pelletized by underwater strand cutting. After pelletizing, dry it at a temperature above 80 °C for more than 2 hours, and then discharge and package to obtain the bio-based modified meltblown material B#.

[0049] Example 3:

[0050] The formula of bio-based modified meltblown material C# is as follows:

[0051] By weight percentage: PLA (same as in Example 1) 45%; PBSA (same as in Example 1) 42%; antioxidant (168) 0.2%; PETS 0.8%; CaSt 0.6%; nucleating agent (3988) 0.4%; PBSA-g-GMA 2.5%; PE wax 8.5%.

[0052] Preparation of bio-based modified meltblown material C#:

[0053] Mix the above components according to the stated weight percentages. First, use a high-low speed stirring mixer to stir at a high speed of 1400 r / min at 55 °C for 3 minutes, and then stir at a low speed of 400 r / min at 25 °C for 5 minutes. Feed the premixed material obtained by stirring into a twin-screw extruder. The conditions of the twin-screw extruder are as follows: set the die head at 210 °C, the metering section at 200 °C, the plasticizing section at 195 °C, the feeding section at 170 °C, and the screw speed at 280 r / min. The material after melt extrusion is pelletized by underwater strand cutting. After pelletizing, it is dried at a temperature above 80 °C for more than 2 hours, and then discharged for packaging to obtain the bio-based modified meltblown material C#.

[0054] Example 4: Preparation of bio-based meltblown fabric

[0055] Using a single-screw extruder, suck the bio-based meltblown materials A# - C# obtained in Examples 1 - 3 into the hopper of the meltblown machine by an automatic suction feeder. At the preset forming temperature, extrude through the filter screen, screw, and metering pump speed from the die head, and evenly spray high-pressure hot air onto the rotatable mesh belt. After electrostatic treatment, it is then wound up to obtain meltblown fabrics 1# - 3#.

[0056] The preparation process flow is as follows: feeding - extrusion metering - high-pressure spraying - web laying - electrostatic treatment - cutting and winding - packaging and warehousing. Among them, the specific operating conditions are shown in Table 1. The test results of meltblown fabrics 1# - 3# are shown in Table 2.

[0057] Table 1. Meltblown process conditions for preparing meltblown fabrics 1# - 3#

[0058]

[0059] Comparative Example 1

[0060] Using the meltblown process conditions of meltblown fabric 1# in Example 4, prepare a polypropylene meltblown fabric with polypropylene as the raw material.

[0061] The following Table 2 lists the comparison of the performance of the bio-based meltblown fabric prepared in the examples of the present invention with the polypropylene meltblown material in Comparative Example 1.

[0062] Table 2. Performance comparison between biodegradable meltblown fabric and polypropylene meltblown fabric

[0063]

[0064] The properties of the bio-based meltblown fabric obtained by using the preparation process of the present invention are as follows: melting point 120 - 130 °C, melt flow rate (MFR190 °C / 2.16 Kg) 1200 - 1400 g / 10 min, tensile strength 35 - 40 MPa, elongation at break 250 - 300%, degradation rate > 99% (38 days), uric acid degradation rate > 99% (48 days), and the toxicity and hygiene indicators are actually non-toxic, meeting the FDA certification. It is not difficult to see from the comparison in Table 2 that the bio-based meltblown fabric obtained by using the preparation process of the present invention can completely replace the petroleum plastic polypropylene meltblown fabric product, and it is non-toxic, harmless, pollution-free, and completely degradable. The product can be produced with general meltblown equipment, the process has strong adaptability, is more environmentally friendly, and has market competitiveness.

Claims

1. A bio-based modified meltblown material, comprising: A mixture and / or its reaction product of polylactic acid, poly(butylene succinate-co-adipate), nucleating agent, and compatibilizer.

2. The bio-based modified meltblown material according to claim 1, wherein the weight-average molecular weight of the polylactic acid is 250,000 to 300,000, preferably 250,000 to 260,000; and / or, the melt flow rate of the polylactic acid is 25 to 32 g / 10 min, preferably 28 to 30 g / 10 min; and / or, the weight-average molecular weight of the poly(butylene succinate-co-adipate) is 227,000 to 235,000, preferably 227,000 to 230,000; and / or, the melt flow rate of the poly(butylene succinate-co-adipate) is 20 to 30 g / 10 min, preferably 25 to 28 g / 10 min; and / or, the nucleating agent is an organic nucleating agent, preferably bis(3,4-dimethylbenzylidene)sorbitol; and / or, the compatibilizer is selected from graft copolymers of aliphatic dibasic acid / aliphatic diol copolyesters and glycidyl methacrylate, preferably at least one selected from graft copolymers of poly(butylene succinate-co-adipate) and glycidyl methacrylate, graft copolymers of poly(butylene succinate) and glycidyl methacrylate; and / or, the bio-based modified meltblown material further comprises at least one of antioxidant, lubricant, heat stabilizer, and dispersant.

3. The bio-based modified meltblown material according to claim 2, wherein the antioxidant is selected from phosphite antioxidants, preferably at least one selected from tris(2,4-di-tert-butylphenyl)phosphite, tris(nonylphenyl)phosphite; and / or, the lubricant is selected from at least one of pentaerythritol stearate, erucamide; and / or, the heat stabilizer is selected from at least one of calcium stearate, sodium stearate; and / or, the dispersant is selected from polyolefin waxes. Preferably, the polyolefin wax is selected from at least one of polyethylene wax and polypropylene wax, and the number-average molecular weight of the polyolefin wax is 1500 to 1700.

4. The bio-based modified meltblown material according to claim 2, wherein taking the total weight percentage of the bio-based modified meltblown material as 100%, the polylactic acid is 30 to 70%, the poly(butylene succinate-co-adipate) is 25 to 70%, the nucleating agent is 0.1 to 0.8%, the compatibilizer is 0.5 to 5%, the antioxidant is 0.01 to 0.5%, the lubricant is 0.1 to 2%, the heat stabilizer is 0.1 to 2%, and the dispersant is 3 to 15%; Preferably, taking the total weight percentage of the bio-based modified meltblown material as 100%, the polylactic acid is 40 to 50%, the poly(butylene succinate-co-adipate) is 35 to 50%, the nucleating agent is 0.2 to 0.5%, the compatibilizer is 1.5 to 3%, the antioxidant is 0.1 to 0.2%, the lubricant is 0.5 to 1%, the heat stabilizer is 0.5 to 1%, and the dispersant is 6 to 10%.

5. A preparation method of the bio-based modified meltblown material according to any one of claims 1 to 4, comprising: The components including the polylactic acid, poly(butylene succinate-adipate-butylene glycol), nucleating agent, and compatibilizer are premixed and then melt-extruded to obtain the bio-based modified meltblown material.

6. The preparation method according to claim 5, wherein the water content of the polylactic acid is 1000-1500 ppm; and / or, the water content of the poly(butylene succinate-adipate-butylene glycol) is 1500-2000 ppm; and / or, at least one of an antioxidant, a lubricant, a heat stabilizer, and a dispersant is further added during the premixing process; and / or, the premixing includes steps of high-speed stirring and low-speed stirring; and / or, the melt extrusion is completed on a twin-screw extruder.

7. The preparation method according to claim 6, wherein the conditions of the high-speed stirring are: temperature 50-60°C, rotation speed 1200-1500 rpm; and / or, the conditions of the low-speed stirring are: temperature 20-25°C, rotation speed 300-500 rpm; and / or, the conditions of the twin-screw extruder are: die head 200-220°C, metering section 190-210°C, plasticizing section 160-180°C, feeding section 150-180°C, and screw rotation speed 250-300 r / min.

8. The bio-based modified meltblown material according to any one of claims 1 to 4, or the bio-based modified meltblown material obtained by the preparation method according to any one of claims 5 to 7, characterized in that The melt index of the bio-based modified meltblown material is 1200-1400 g / 10 min.

9. A bio-based meltblown fabric is prepared by processing a bio-based modified meltblown material through a meltblowing device, and the bio-based modified meltblown material is the bio-based modified meltblown material according to any one of claims 1-4 or the bio-based modified meltblown material obtained by the preparation method according to any one of claims 5-7.

10. The application of the bio-based modified meltblown material according to claim 8 or the bio-based meltblown fabric according to claim 9 in medical supplies and sanitary products. Preferably, the bio-based modified meltblown material or bio-based meltblown fabric is used to replace disposable masks, disposable wet and dry alcohol cotton balls for epidemic prevention and medical use, or replace disposable wet and dry napkins in the catering industry, or replace disposable facial masks in the beauty industry, or replace disposable diapers and absorbent pad cloths.

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