Degradable mask base cloth added with lecithin and preparation method of degradable mask base cloth

Abstract

The invention discloses degradable mask base cloth added with lecithin and a preparation method of the degradable mask base cloth, and belongs to the technical field of biological materials. The base cloth is prepared by taking polylactic acid (PLA) and poly (butylene adipate-co-terephthalate) (PBAT) as a composite matrix and adding hydrogenated lecithin through an electrostatic spinning process. The preparation method comprises the following steps: dissolving PLA and PBAT in hexafluoroisopropanol according to a mass ratio of (60-80): (20-35) to form a 12wt% spinning solution, adding lecithin, carrying out ultrasonic dispersion for 30 minutes, carrying out electrostatic spinning to form fibers, and carrying out ethanol steam cross-linking curing. Experiments show that the contact angle of the base cloth added with lecithin is reduced to 52.3 degrees, the liquid carrying rate reaches 415%, the 28-day soil degradation rate reaches 75.2%, the tensile strength is 8.7 MPa, and the relative proliferation rate is 98.6%. The lecithin improves the hydrophilicity of the polymer through hydrogen-bond interaction, and the amphiphilic structure of the lecithin promotes microbial attachment and synergistically improves the degradation efficiency.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological materials, and particularly relates to a degradable mask base cloth added with lecithin and a preparation method thereof. BACKGROUND

[0002] The current mainstream mask base cloth is mostly made of non-degradable synthetic fibers (such as polypropylene and polyethylene), and the annual waste amount exceeds 10 billion pieces. It takes more than 200 years to degrade in the natural environment, resulting in serious microplastic pollution. The European Union ECHA draft in 2023 requires that the cosmetic packaging materials meet the 90% degradability by 2027, and it is urgent to develop environmentally friendly alternative materials.

[0003] The existing degradable base cloth is mainly made of pure polylactic acid (PLA) or viscose fiber. The pure PLA base cloth has obvious defects: the surface contact angle is greater than 100°, resulting in poor hydrophilicity (liquid loading rate is less than 200%); the glass transition temperature (about 60℃) is close to the skin temperature, and the skin adhesion is insufficient; it takes more than 180 days to completely degrade in the natural environment, and the degradation process produces debris residues. Although viscose fiber has hydrophilicity, its wet strength is low (less than 1.5 MPa), and it is easy to break during use. The use of CS2 solvent in the production process causes environmental pollution.

[0004] Lecithin, as a natural amphoteric surfactant, is commonly used as an emulsifier in the cosmetic field, but its application in degradable fibers has technical bottlenecks. CN107419450A attempts to add lecithin to cellulose film, but the degradation rate is only increased by 15% due to poor compatibility; JP2018158567A uses PLA / lecithin blending injection molding, but lecithin has a low thermal decomposition temperature (190℃) which is lower than the processing temperature of PLA (210℃), resulting in failure. The existing technology has not yet solved the problems of processing compatibility and long-term degradation promotion mechanism of lecithin and polyester materials. SUMMARY

[0005] To solve the problems of processing compatibility and long-term degradation of lecithin and polyester materials.

[0006] To solve the above problems, the present application provides the following technical solutions:

[0007] A degradable mask base cloth added with lecithin, characterized in that it comprises 50-70 wt% of polylactic acid (PLA), 20-35 wt% of polybutylene adipate terephthalate (PBAT), and 5-15 wt% of lecithin.

[0008] Preferably, the molecular weight of the PLA is 80-150 thousand, and the melt flow rate of the PBAT is 3-6 g / 10 min (190℃ / 2.16 kg).

[0009] Preferably, the lecithin is hydrogenated soybean lecithin with phosphatidylcholine content ≥ 85% and iodine value ≤ 5 gI2 / 100 g.

[0010] Preferably, the base cloth has a swelling rate of 180-220% in deionized water at 25°C.

[0011] Preferably, the base cloth has a 28-day soil degradation weight loss rate of > 70%.

[0012] Preferably, the base cloth has a glass transition temperature (Tg) of 42-46°C.

[0013] Preferably, the base cloth has a fiber diameter distribution of 0.8-1.5 μm and a pore size of 10-30 μm.

[0014] A method for preparing a degradable facial mask base cloth with added lecithin, characterized by comprising the following steps:

[0015] S1: Dissolve PLA and PBAT in hexafluoroisopropanol at a mass ratio of (60-80):(20-35) to prepare a 10-15 wt% solution;

[0016] S2: Add lecithin and ultrasonically disperse (40 kHz, 300 W) at 25°C for 30 minutes;

[0017] S3: Electrospinning process parameters: voltage 18-22 kV, receiving distance 15-25 cm, solution flow rate 0.8-1.2 mL / h.

[0018] Preferably, the surface temperature of the spinning receiving device in S3 is controlled at 40-45°C.

[0019] Preferably, after spinning in S3, crosslinking in ethanol saturated steam for 20-30 minutes, steam temperature 45-50°C.

[0020] The effects and advantages of the degradable facial mask base cloth with added lecithin and the method for preparing the same according to the present application are:

[0021] 1. In this patent, the lecithin phosphate group forms a hydrogen bond with the PLA ester bond, weakening the polymer molecular chain force and accelerating hydrolysis; the hydrophobic end attracts microbial lipase secretion, and the 28-day degradation rate is increased by 138.7% (compared to the non-addition group).

[0022] 2. In this patent, lecithin is oriented on the fiber surface, the contact angle is reduced to 52.3°, the liquid loading rate is increased to 415%, and the pH is stabilized at 6.2-6.8.

[0023] 3. In this patent, ethanol vapor crosslinking raises the melting point of lecithin from 50°C to 75°C, avoiding thermal decomposition during electrospinning.

[0024] 4, The patent, lecithin as an internal plasticizer, the elongation at break is increased to 35.8% (control group 22.1%), and the tensile strength is maintained at 8.7 MPa. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a flow chart of a degradable facial mask base cloth added with lecithin and a preparation method thereof in the present application. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application,

[0027] It should be noted that, in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations, and the term "include", "contain" or any other variant is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the elements defined by the statement "include" do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0028] Embodiment 1

[0029] Reference Figure 1 The embodiment provides a degradable facial mask base cloth added with lecithin and a preparation method thereof, which is suitable for the technical field of biological materials and includes the following implementation contents:

[0030] Experimental purpose:

[0031] A degradable facial mask base cloth added with lecithin and a preparation method thereof, which verifies the comprehensive performance of 12wt% lecithin addition amount.

[0032] Experimental raw materials:

[0033] 65 g of polylactic acid (PLA, Mn = 100,000), 23 g of PBAT (melting index 4.5 g / 10 min), 12 g of hydrogenated lecithin (PC 88%), 800 mL of hexafluoroisopropanol (HFIP), and 200 mL of anhydrous ethanol.

[0034] Experimental equipment:

[0035] Electrospinning machine, ultrasonic disperser, constant temperature magnetic stirrer, steam crosslinking device, vacuum drying oven.

[0036] Experimental steps:

[0037] S1: Solution preparation, pour PLA and PBAT into a three-necked flask containing 600 mL HFIP, 50°C water bath magnetic stirring for 4 hours to completely dissolve, add the remaining 200 mL HFIP dilution, continue to stir for 30 minutes to get a uniform solution, add lecithin powder, ultrasonic dispersion (300W, 40kHz) for 30 minutes (interval 5 minutes pause to prevent overheating) at 25°C;

[0038] S2: Electrospinning, inject the spinning solution into a 5 mL glass needle tube (needle diameter 0.6 mm), working voltage 20 kV (ambient humidity ≤40%), receiving distance 20 cm, solution flow rate 1.0 mL / h, aluminum foil receiving substrate temperature 40°C (closed loop control by thermocouple), continuous spinning for 90 minutes, forming a fiber mat with thickness ≈0.15 mm on the aluminum foil;

[0039] S3: Post-processing, move the fiber mat into the steam crosslinking device, pass in 50°C ethanol saturated steam (flow rate 3 L / min), treat for 25 minutes, take out the substrate and place it in a vacuum drying oven, dry at 60°C for 2 hours (vacuum degree 0.1 Pa), cut the sample after cooling.

[0040] Experimental results: Details are shown in Table 1.

[0041] Table 1: Test results of Example 1

[0042]

[0043] Example 1 A kind of degradable face mask base cloth added lecithin and its preparation method, experimental data show that the comprehensive performance of base cloth is significantly improved by adding 12wt% lecithin: the hydrophilicity is significantly improved due to the intermolecular hydrogen bond formed by the phosphate group of lecithin and the ester bond of PLA / PBAT, and the contact angle is reduced to 52.3° due to the directional arrangement of the hydrophilic layer on the fiber surface; the liquid loading rate jumps to 415% due to the capillary effect caused by the lecithin micelles embedded in the fiber network, and the amphiphilic structure reduces the liquid surface tension; the mechanical strength is optimized due to the plasticizing effect of lecithin long-chain alkane, which makes the stress distribution uniform, slightly reduces the strength while giving 35.8% high ductility; the degradation rate is increased by 75.2%, which is because the hydrophobic end (fatty acid chain) of lecithin serves as a microbial carbon source, which greatly increases the hydrolysis site and accelerates the ester bond rupture of PLA main chain induced by phase separation interface; the 98.6% proliferation rate of biological safety proves that ethanol vapor crosslinking effectively fixes lecithin, eliminating the membrane structure interference of free phospholipids on cells. The above data systematically verify that lecithin realizes performance synergistic effect through the triple cooperative effect of "interface modification-plasticizing-biological activation".

[0044] Example 2

[0045] The embodiment provides a kind of degradable face mask base cloth added lecithin and its preparation method, including the following implementation content:

[0046] Experimental purposes:

[0047] A kind of degradable face mask base cloth added lecithin and its preparation method, explore the regulation mechanism of PLA and PBAT in 65:35, 60:40 and 70:30 three mass ratios (fixed lecithin 12wt%) on the mechanical strength, degradation and swelling behavior of base cloth.

[0048] Experimental raw materials:

[0049] Polylactic acid PLA (group 1: 70g, group 2: 65g, group 3: 60g), PBAT (group 1: 30g, group 2: 35g, group 3: 40g), hydrogenated lecithin (PC 88%) 12g, hexafluoroisopropanol (HFIP) 800mL, anhydrous ethanol 200mL.

[0050] Experimental steps:

[0051] S1: solution preparation, according to the ratio of three groups, respectively weigh PLA / PBAT, dissolve in 600mL HFIP, 50℃ magnetic stirring 4 hours to transparent solution, supplement HFIP to total solid content 12wt%, add 12g lecithin, ultrasonic dispersion for 30 minutes (300W, 40kHz) at 25℃;

[0052] S2: electrospinning, voltage 20 kV, receiving distance 20 cm, flow rate 1.0 mL / h, aluminum foil temperature 40℃, continuous spinning for 90 minutes for each group, to prepare a base cloth with a thickness of 0.15±0.02 mm;

[0053] S3: post-processing, 50℃ ethanol vapor crosslinking for 25 minutes, 60℃ vacuum drying for 2 hours.

[0054] Experimental results: see Table 2 for details.

[0055] Table 2: Test results of Example 2

[0056]

[0057] Example 2: A degradable facial mask base cloth added with lecithin and a preparation method thereof, the data show that

[0058] The mass ratio of PLA / PBAT has a significant regulatory effect on performance: the tensile strength of the 65:35 group is the largest (9.1 MPa) due to the limiting compatible ratio of PLA and PBAT, and the hydrogen bonding energy of the carbonyl group (C=O) of PLA and the ester group (-COO-) of PBAT is the strongest at this ratio, forming a dense physical crosslinking network; when the PBAT increases to 40%, the phase separation is intensified, and the dispersion degree of the rigid segment of PLA decreases, resulting in a sharp decrease in strength to 7.2 MPa. The elongation at break increases with the increase of the ratio of PBAT, which is due to the internal plasticizing effect of the soft segment (butadiene unit) of PBAT, which promotes the dispersion of local deformation energy. The degradation rate of the 60:40 group is the highest (78.3%) driven by two factors: expansion of the amorphous region, and the crystallinity of XRD decreases from 36.1% (70:30 group) to 25.4%, the amorphous ratio increases to increase the water molecule penetration channel (swelling rate increases to 225%), accelerating the hydrolysis of the ester bond of PLA; microbial targeting attack, the aliphatic segment (adipic acid unit) in PBAT is more easily recognized by the lipase secreted by microorganisms, and lecithin is enriched at the phase interface to form an "enzyme attack site amplifier". The swelling rate and the strength are antagonistic, and the low swelling rate (195%) of the 70:30 group is due to the semi-crystalline barrier formed by the high PLA content, but excessive crystallization inhibits the water diffusion path, which in turn results in the lowest degradation rate (69.7%); the swelling rate of the 65:35 group is 210%, which confirms that the moderate crosslinking network can not only maintain the mechanical stability, but also ensure the effective penetration of the degradation medium.

[0059] Example 3

[0060] This example provides a degradable facial mask base cloth added with lecithin and a preparation method thereof, which optimizes the ethanol vapor crosslinking time, including the following implementation contents:

[0061] Experimental purposes:

[0062] A kind of degradable face mask base cloth added lecithin and its preparation method, explore the influence of different ethanol vapor crosslinking length (10 / 20 / 30 min) on lecithin immobilization efficiency, fiber morphology and functional durability.

[0063] Experimental raw materials:

[0064] Polylactic acid (PLA, Mn=100,000) 65g, PBAT (melting finger 4.5g / 10min) 23g, hydrogenated lecithin (PC 88%) 12g, hexafluoroisopropanol (HFIP) 800mL, anhydrous ethanol 200mL.

[0065] Experimental steps:

[0066] S1: base cloth preparation, prepare three groups of same base cloth (thickness 0.15mm) according to the process of embodiment 1;

[0067] S2: gradient crosslinking treatment, group A: 50 DEG C ethanol vapor crosslinking 10 minutes (vapor flow rate 3L / min);Group B: 20 minutes (same condition);Group C: 30 minutes (same condition);

[0068] S3: post-processing, 60 DEG C vacuum drying 2 hours, cut test sample.

[0069] Experimental results: details see table 3.

[0070] Table 3: the test results of embodiment 3

[0071]

[0072]

[0073] Example 3 A kind of degradable face mask base cloth added lecithin and its preparation method, the elution rate of 20min group is lowest (3.2%), which is caused by phospholipid bilayer reconfiguration, ethanol vapor induces lecithin hydrophobic tail (C18 alkane) unfolding, and its choline phosphate polar head is combined with PLA / PBAT carbonyl through van der waals force and hydrogen bond; Short time processing (10min) cannot complete molecular rearrangement, resulting in 24.7% lecithin elution; Although the elution rate of 30min group is lower, solvent swelling causes fiber erosion. The diameter uniformity of 20min group is best, ethanol forms diffusion-evaporation balance on the surface of the fiber, which makes the polymer slowly glassify; The fiber of 10min group is adhered due to residual solvent; Excessive solvent penetration of 30min group causes fiber swelling and deformation, and the difference in local evaporation rate induces phase separation and coarsening. The modulus decay rate of 20min group is lowest (28.1%), which is attributed to the "double network" cross-linked structure, and lecithin forms a dense molecular layer at the interface to inhibit water molecule penetration, while PBAT soft segment dissipates deformation energy; Water molecules attack the polymer backbone due to the loss of lecithin in 10min group; Although the immobilization of lecithin in 30min group is enhanced, the stress concentration coefficient increases due to fiber coarsening, which accelerates wet state failure.

[0074] Comparative Example 1

[0075] A kind of traditional degradable face mask base cloth and its preparation method are provided, and the performance of the formula without lecithin is compared, including the following implementation contents:

[0076] Experimental purposes:

[0077] A kind of traditional degradable face mask base cloth and its preparation method are provided, and the performance of the formula without lecithin is compared, including the following implementation contents:

[0078] Experimental raw materials:

[0079] 65g of polylactic acid (PLA, Mn=100,000), 35g of PBAT (melting index 4.5g / 10min), 800mL of hexafluoroisopropanol (HFIP), and 200mL of anhydrous ethanol.

[0080] Experimental steps:

[0081] S1: solution preparation, pour PLA and PBAT into a three-necked flask containing 600mL of HFIP, magnetically stir in a 50℃ water bath for 4 hours until completely dissolved, add the remaining 200mL of HFIP for dilution, continue to stir for 30 minutes to obtain a uniform solution, ultrasonic dispersion (300W, 40kHz) for 30 minutes (pause for 5 minutes to prevent overheating);

[0082] S2: Electrospinning, the spinning solution was injected into a 5 mL glass needle tube (needle diameter 0.6 mm), the working voltage was 20 kV (ambient humidity ≤ 40%), the receiving distance was 20 cm, the solution flow rate was 1.0 mL / h, the aluminum foil receiving substrate temperature was 40 °C (closed loop control by thermocouple), continuous spinning for 90 minutes, forming a fiber mat with a thickness of ≈0.15 mm on the aluminum foil;

[0083] S3: Post-processing, the fiber mat was moved into a steam crosslinking device, saturated steam of 50 °C ethanol was introduced (flow rate 3 L / min), treated for 25 minutes, the substrate was taken out and placed in a vacuum drying oven, dried at 60 °C for 2 hours (vacuum degree 0.1 Pa), after cooling, the sample was cut.

[0084] Experimental results: see Table 4 for details.

[0085] Table 4: Test results of Comparative Example 1

[0086]

[0087] Comparative Example 1 provides a traditional degradable facial mask substrate and its preparation method, the water contact angle is 108.7°, the PLA / PBAT molecular chain is densely stacked to form a low-energy surface, wherein the methyl side chain of PLA and the aromatic ring structure of PBAT are exposed to the interface, which significantly reduces the surface polarity, the absence of lecithin makes the material lose the strong hydrophilicity of phosphocholine groups, and water molecules cannot effectively spread. The liquid carrying rate of 288% depends on the synergistic effect of fiber network capillary effect and polymer hydrophilicity, the fiber surface is smooth without lecithin, the pore size distribution is concentrated, which is significantly smaller than the lecithin-containing group, resulting in a decrease in capillary force; the PLA / PBAT molecular chain hydrophobic barrier hinders the penetration of body fluid, and the double effect limits the liquid carrying rate. The high tensile strength of 9.8 MPa is due to the continuous phase of the PLA crystalline region, but the elongation at break is only 22.1%, which shows typical brittle fracture characteristics, and the absence of lecithin reduces the interfacial bonding energy of PLA / PBAT, and the stress transfer efficiency is low, micro-cracks occur preferentially at the phase interface under external force, and the toughening effect of PBAT flexible chain cannot be fully played. The low degradation rate of 31.5% is due to three obstacles: ① hydrolysis barrier, the PLA crystalline region forms a dense hydrophobic layer, preventing water molecules from penetrating; ② microbial barrier, the absence of lecithin on the surface reduces the density of microorganisms; ③ enzymatic barrier, degradation only occurs on the surface, and the soil metagenome shows that the expression amount of lipase gene is only 1.7 RPKM (12.3 RPKM for the lecithin-containing group). The relative proliferation rate of 97.3% meets the ISO 10993-5 standard (> 80%), which is due to two mechanisms: ① ethanol crosslinking effectively removes residual solvents; ② PLA / PBAT degradation products lactic acid and succinic acid are intermediates in human metabolism, and have no specific toxicity. However, it should be noted that the absence of lecithin leads to the loss of membrane structure protection, and long-term contact may cause keratinocyte dehydration.

[0088] Example 1 provides a degradable facial mask substrate with lecithin addition and its preparation method. The experiment verifies the significant improvement of the degradable facial mask substrate performance with the addition of 12wt% lecithin. The water contact angle is reduced to 52.3°, indicating that the lecithin phosphate group forms hydrogen bonds with PLA / PBAT and is oriented on the fiber surface, greatly enhancing the hydrophilicity. The liquid loading rate reaches 415%, resulting from the capillary effect of lecithin micelles embedded in the fiber network and the reduction of liquid surface tension by its amphiphilic structure. In terms of mechanical properties, the tensile strength is 8.7 MPa, and the elongation at break is 35.8%, reflecting the plasticizing effect of lecithin long-chain alkane, which makes the stress distribution uniform. The 28-day degradation rate is as high as 75.2%, as the hydrophobic end of lecithin serves as a carbon source for microorganisms, accelerating the hydrolysis of PLA ester bonds; the cytotoxicity test shows a relative proliferation rate of 98.6%, confirming that ethanol vapor crosslinking effectively fixes lecithin, eliminating the interference of free phospholipids on cells. The data show that lecithin optimizes performance through the triple mechanism of "interface modification-plasticization-biological activation".

[0089] Example 2 explores the effect of PLA / PBAT mass ratio on the performance of the substrate. The 65:35 group (PLA) has the highest tensile strength (9.1 MPa), as the PLA carbonyl group and PBAT ester group form the strongest hydrogen bond combination at this ratio, forming a dense physical crosslinking network; while the PBAT increases to 40%, the phase separation intensifies, and the strength decreases to 7.2 MPa. The elongation at break increases with the increase of PBAT ratio, due to the internal plasticizing effect of PBAT soft segment. The 60:40 group has the highest degradation rate (78.3%), as the expansion of amorphous regions increases the water molecule penetration channels, and PBAT aliphatic segments are more easily attacked by microorganisms. The swelling rate is positively correlated with the PBAT content, but the 65:35 group has a swelling rate of 210%, indicating that it balances the mechanical stability and degradation medium permeability, confirming that this ratio is the optimal ratio.

[0090] Example 3 focuses on the effect of ethanol vapor crosslinking time on the efficiency of lecithin immobilization. The 20-minute group performs best: lecithin elution rate is only 3.2%, as ethanol vapor induces the reconstruction of its hydrophobic tail and forms stable combination with PLA / PBAT; the fiber diameter uniformity is best (CV value 12.3%), due to the solvent diffusion-evaporation balance; the wet modulus decay rate is lowest (28.1%), as the lecithin interface layer inhibits water molecule penetration. The 10-minute group has 24.7% lecithin elution and fiber adhesion due to insufficient crosslinking; the 30-minute group has a lower elution rate (2.1%), but excessive solvent penetration causes fiber erosion (coefficient of variation of diameter 35.7%), proving that 20 minutes is the optimal crosslinking time.

[0091] Comparative Example 1, without lecithin, showed significantly deteriorated performance: water contact angle as high as 108.7° due to lack of lecithin phosphatidylcholine hydrophilic groups on the PLA / PBAT hydrophobic surface; liquid loading rate only 288% due to weakened capillary effect of the fiber network and the polymer hydrophobic barrier. Mechanical properties showed brittle characteristics (tensile strength 9.8 MPa, elongation at break 22.1%) due to low interfacial bonding energy of PLA / PBAT. Degradation rate only 31.5% in 28 days due to the dense hydrophobic layer of crystalline regions hindering hydrolysis and low microbial adhesion density due to lack of lecithin targeting sites. Cell proliferation rate 97.3% was up to standard, but long-term exposure could cause keratinocyte dehydration, highlighting the key role of lecithin in protecting membrane structure.

[0092] Those skilled in the art can understand that the modules and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware, and whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0093] In addition, each functional module in each embodiment of the present application can be integrated into one processing module, or each module can exist physically alone, or two or more modules can be integrated into one module.

[0094] The above is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any skilled person in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0095] Finally, the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection of the present application.

Claims

1. A biodegradable facial mask base fabric with added lecithin, characterized in that... It contains 50-70 wt% polylactic acid (PLA), 20-35 wt% polybutylene adipate terephthalate (PBAT), and 5-15 wt% lecithin.

2. The biodegradable mask base fabric with added lecithin as described in claim 1, characterized in that, The PLA has a molecular weight of 80,000-150,000, and the PBAT melt flow rate is 3-6 g / 10 min (190℃ / 2.16 kg).

3. The biodegradable mask base fabric with added lecithin as described in claim 1, characterized in that, The lecithin is hydrogenated soybean lecithin, with a phosphatidylcholine content ≥85% and an iodine value ≤5gI2 / 100g.

4. The biodegradable mask base fabric with added lecithin as described in claim 1, characterized in that, The base fabric has a swelling rate of 180-220% in deionized water at 25°C.

5. The biodegradable mask base fabric with added lecithin as described in claim 1, characterized in that, The base fabric experienced a weight loss rate of >70% after 28 days of soil degradation.

6. The biodegradable mask base fabric with added lecithin as described in claim 1, characterized in that, The glass transition temperature (Tg) of the base fabric is 42-46℃.

7. The biodegradable mask base fabric with added lecithin as described in claim 1, characterized in that, The base fabric fibers have a diameter distribution of 0.8-1.5 μm and a pore size of 10-30 μm.

8. A method for preparing a biodegradable facial mask base fabric with added lecithin, characterized in that, Includes the following steps: S1: Dissolve PLA and PBAT in hexafluoroisopropanol at a mass ratio of (60-80):(20-35) to prepare a 10-15wt% solution; S2: Add lecithin and ultrasonically disperse at 25°C (40kHz, 300W) for 30 minutes; S3: Electrospinning process parameters: voltage 18-22kV, receiving distance 15-25cm, solution flow rate 0.8-1.2mL / h.

9. The method for preparing a biodegradable facial mask base fabric with added lecithin as described in claim 8, characterized in that, The surface temperature of the spinning receiving device in S3 is controlled at 40-45℃.

10. The method for preparing a biodegradable facial mask base fabric with added lecithin as described in claim 8, characterized in that, In the S3 process, after spinning, the fibers are crosslinked in saturated ethanol vapor for 20-30 minutes at a vapor temperature of 45-50°C.

Images