A composite fiber membrane, its preparation method and application

Abstract

This invention discloses a composite fiber membrane, its preparation method, and its applications. The composite fiber membrane comprises a substrate, a PHBV fiber membrane, and a face material arranged sequentially from bottom to top. The PHBV fiber membrane includes nano-PHBV fibers and micro-PHBV fibers. In the technical solution provided by this invention, the PHBV fiber membrane comprises a hierarchical structure fiber membrane with both nano-PHBV and micro-PHBV fibers, achieving a PM0.3μm filtration efficiency of over 90%. Furthermore, PHBV is a bio-derived material with a rapid degradation rate. By combining the successfully prepared hierarchical PHBV fiber membrane with the substrate and face material to form a three-layer sandwich structure, a highly efficient, low-resistance, biodegradable composite fiber membrane with a low risk of electret material failure can be prepared.

Description

Technical Field

[0001] This invention relates to the field of materials, specifically to a composite fiber membrane, its preparation method, and its application. Background Technology

[0002] Particulate matter (PMs) pollution has become a global concern, posing a significant burden on public health. Current public health protection measures primarily involve wearing PP masks to block PMs; however, as PP masks are made of non-degradable plastic, their widespread use places immense pressure on the environment. Therefore, developing a high-efficiency, low-resistance, biodegradable mask is crucial for improving public health and protecting the ecological environment. PMs are mixtures of various atmospheric pollutants, primarily classified into PM0.3, PM2.5, and PM10 based on their hydrodynamic volume, referring to particles with hydrodynamic diameters of 0.3, 2.5, and 10 μm and below, respectively. PM0.3, due to its extremely strong penetrating power and long transmission distance, can penetrate the tiny airways of the human body. Furthermore, PM0.3 can carry various bacteria and viruses, which, once inside the body, have a certain probability of inducing cardiovascular and respiratory diseases, posing a significant threat to human health. Currently, commercially available masks are primarily made of non-degradable PP material, resulting in millions of tons of non-degradable plastic waste that puts enormous pressure on the environment. Therefore, finding biodegradable materials to manufacture high-performance masks is urgently needed.

[0003] Traditional PP masks are primarily constructed by attaching electret material to micron-sized fibers (around 3 micrometers) to form a modified micron-sized PHBV fiber membrane. The production process typically involves melt spinning followed by electret particle polarization. This involves adding the appropriate electret material to PP melt, performing melt spinning, and then placing the resulting fiber membrane in a strong electric field to polarize the electret material and make it electrostatically charged. The resulting modified PP micron-sized PHBV fiber membrane possesses a certain physical interception capability for PM2.5 and PM10, while the electrostatically charged electret particles exhibit strong electrostatic adsorption of PMs. Therefore, its filtration efficiency for PM2.5 can generally reach over 99%. However, due to its relatively large fiber diameter and pore size, it cannot effectively intercept and adsorb nano-sized PM0.3. Furthermore, the moisture in exhaled breath easily causes the electret material to degrade. Once the electret material degrades, the filtration efficiency of the PP mask for PMs drops drastically. Therefore, the effective usage time of PP masks is very short, typically around 4 hours. Summary of the Invention

[0004] The main objective of this invention is to propose a composite fiber membrane, its preparation method, and its application, in order to solve the problems in the prior art where micron-sized PHBV fiber membranes cannot effectively intercept and adsorb nano-sized PM0.3, and where water vapor in human exhaled air easily leads to the failure of electret materials.

[0005] This invention proposes a composite fiber membrane, comprising a substrate, a PHBV fiber membrane, and a face material arranged sequentially from bottom to top, wherein the PHBV fiber membrane includes nano PHBV fibers and micron PHBV fibers.

[0006] Optionally, the diameter of the nano-PHBV fibers is less than or equal to 50 nm; and / or,

[0007] The diameter of the micron-sized PHBV fibers is 2–10 μm; and / or,

[0008] The thickness of the PHBV fiber membrane is 50–200 μm.

[0009] Optionally, the volume ratio of the nano-PHBV fiber to the micron-PHBV fiber is (1.5 to 4):1.

[0010] Optionally, the substrate material includes any one of PVA spunlace nonwoven fabric, PLA nonwoven fabric, chitosan nonwoven fabric, and release paper; and / or,

[0011] The material of the face material includes any one of PVA spunlace nonwoven fabric, PLA nonwoven fabric, chitosan nonwoven fabric, and release paper.

[0012] This invention also proposes a method for preparing a composite fiber membrane, wherein the composite fiber membrane comprises a substrate, a PHBV fiber membrane, and a face material arranged sequentially from bottom to top, wherein the PHBV fiber membrane comprises nano-PHBV fibers and micro-PHBV fibers. The method includes the following steps:

[0013] S10, Provide a receiving base;

[0014] S10. Prepare the HFP solution of PHBV and electrospin the HFP solution of PHBV on the receiving substrate to obtain a PHBV fiber membrane.

[0015] S30. Composite material is laminated onto the PHBV fiber membrane to obtain a composite fiber membrane.

[0016] Optionally, in step S10, the concentration of PHBV in the HFP solution of PHBV is 4 wt.% to 8 wt.%.

[0017] Optionally, in step S20,

[0018] The receiving substrate consists of PVA spunlace nonwoven fabric with a density of 20–30 g / m³. 2 ;or,

[0019] The receiving substrate consists of PLA nonwoven fabric with a density of 25–35 g / m³. 2;or,

[0020] The receiving substrate includes chitosan nonwoven fabric with a density of 30–40 g / m³. 2 .

[0021] Optionally, in step S20,

[0022] The humidity range for electrospinning is 60% to 95% RH; and / or,

[0023] The voltage for electrospinning is 15–20 kV; and / or,

[0024] The spinning distance for electrospinning is 15–30 cm; and / or,

[0025] The feed rate for electrospinning is 1–2 mL / h.

[0026] The present invention also proposes a medical protective product, including the aforementioned composite fiber membrane, wherein the composite fiber membrane comprises a substrate, a PHBV fiber membrane, and a surface material arranged sequentially from bottom to top, wherein the PHBV fiber membrane comprises nano PHBV fibers and micron PHBV fibers.

[0027] Optionally, the medical protective equipment includes face masks.

[0028] The technical solution provided by this invention includes a PHBV fiber membrane with a hierarchical structure comprising nano- and micro-sized PHBV fibers. Its PM0.3μm filtration efficiency can reach over 90%, and PHBV is a bio-based material with a rapid degradation rate. By combining the successfully prepared PHBV hierarchical fiber membrane with a substrate and a face material to form a three-layer sandwich structure, a highly efficient, low-resistance, biodegradable composite fiber membrane with a low risk of electret material failure can be prepared. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the composite fiber membrane prepared in Example 1 of the present invention;

[0031] Figure 2 This is a schematic diagram of the composite fiber membrane prepared in Example 1 of the present invention;

[0032] Figure 3 This is a schematic diagram of the composite fiber membrane prepared in Example 2 of the present invention;

[0033] Figure 4 This is a schematic diagram of the composite fiber membrane prepared in Example 3 of the present invention;

[0034] Figure 5 This is a schematic diagram of the composite fiber membrane prepared in Example 4 of the present invention.

[0035] Explanation of reference numerals in the accompanying drawings of the embodiments provided in this invention:

[0036] label name label name 100 Composite fiber membrane 21 Nano PHBV Fiber 1 Substrate 22 Micron PHBV fiber 2 PHBV fiber membrane 3 Surface material

[0037] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially. Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, or solution B, or a solution where both A and B are satisfied simultaneously. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Current research on face masks mainly focuses on extending their effective usage time and improving their filtration efficiency for PM0.3. Therefore, there is a need to develop more efficient and longer-lasting filter membranes to replace the existing PP mask filter membranes. Nano-PHBV fibers, due to their smaller fiber diameter and membrane pore size, exhibit more efficient PMs filtration performance compared to PP micron-sized PHBV fibers. Electrospinning is widely used as an efficient method for preparing nano-PHBV fibers. Currently, various materials, such as polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyamide (PA), and polyurethane (PU), have been electrospinned to produce nano-PHBV fiber membranes for use in high-performance face masks. As the filter core layer of these masks, these nano-PHBV fiber filter membranes, compared to traditional PP filter core layers, have ultra-fine fiber diameters and extremely small pore sizes, resulting in higher filtration efficiency for PM0.3 particles. Therefore, they can more effectively prevent airborne bacteria and viruses from being inhaled. The aforementioned electrospun nano-PHBV fiber membranes have achieved the ultimate in protective efficiency. According to published literature, nano-PHBV fiber membranes prepared from materials such as PAN and PVDF can achieve PM0.3 filtration efficiencies of over 90%. However, due to limitations in the mechanical properties and spinnability of materials, high-performance biodegradable nano-PHBV fiber filter membranes are rarely reported. Therefore, given the current environmental protection and public health protection issues, it is crucial to develop a highly efficient biodegradable air filter membrane that can be used as the filter core layer of face masks. In view of this, this invention proposes a composite fiber membrane 100, comprising a substrate 1, a PHBV fiber membrane 2, and a face material 3 arranged sequentially from bottom to top, wherein the PHBV fiber membrane 2 includes nano-PHBV fibers 21 and micron-sized PHBV fibers 22.

[0040] In the technical solution provided by this invention, the PHBV fiber membrane 2 comprises a hierarchical fiber membrane with nano-sized PHBV fibers 21 and micron-sized PHBV fibers 22 coexisting. Its PM0.3 filtration efficiency can reach over 90%, and PHBV is a biologically derived material with a fast degradation rate. By combining the successfully prepared PHBV hierarchical fiber membrane with the substrate 1 and the face material 3 to form a three-layer sandwich structure, a highly efficient, low-resistance, biodegradable composite fiber membrane 100 with an electret material that is not prone to failure can be prepared.

[0041] Furthermore, the diameter of the nano-PHBV fiber 21 is less than or equal to 50 nm. When the diameter of the nano-PHBV fiber 21 is less than or equal to 50 nm, it can better filter fine particulate matter and improve the filtration performance of the composite fiber membrane 100.

[0042] Furthermore, the diameter of the micron-sized PHBV fibers 22 is 2–10 μm. By intercalating the micron-sized PHBV fibers 22 with the nano-sized PHBV fibers 21, the filtration performance of the composite fiber membrane 100 can be improved while maintaining a better spatial network structure. The effect is even better when the diameter of the micron-sized PHBV fibers 22 is 2–10 μm. The diameter of the micron-sized PHBV fibers 22 can be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm.

[0043] It should be noted that the diameters of the nano PHBV fiber 21 and the micron PHBV fiber 22 can be set simultaneously or separately. When set simultaneously, the filtration performance of the composite fiber membrane 100 can be improved while maintaining a better spatial network structure, resulting in the best effect.

[0044] Furthermore, the thickness of the PHBV fiber membrane 2 is 50–200 μm. At this thickness, the filtration performance is better. The thickness of the PHBV fiber membrane 2 can be 50 μm, 100 μm, 150 μm, or 200 μm.

[0045] Furthermore, the volume ratio of the nano-PHBV fiber 21 to the micron-sized PHBV fiber 22 is (1.5–4):1. At this volume ratio, the filtration performance of the composite fiber membrane 100 is improved while maintaining a better spatial network structure, resulting in optimal performance. The volume ratio of the nano-PHBV fiber 21 to the micron-sized PHBV fiber 22 can be 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, or 4:1.

[0046] Furthermore, the material of the substrate 1 includes any one of PVA spunlace nonwoven fabric, PLA nonwoven fabric, chitosan nonwoven fabric, and release paper, and different types of nonwoven fabric can be selected as needed.

[0047] Furthermore, the material of the face material 3 includes any one of PVA spunlace nonwoven fabric, PLA nonwoven fabric, chitosan nonwoven fabric, and release paper. Different types of nonwoven fabrics can be selected as needed.

[0048] It should be noted that the materials of the substrate 1 and the surface material 3 can be set simultaneously or separately, and can be set to be the same or different. Setting them to be the same makes operation easier.

[0049] This invention also proposes a method for preparing a composite fiber membrane, wherein the composite fiber membrane comprises a substrate, a PHBV fiber membrane, and a face material arranged sequentially from bottom to top, wherein the PHBV fiber membrane comprises nano-PHBV fibers and micro-PHBV fibers. The method includes the following steps:

[0050] S10, Provide a receiving base;

[0051] S10. Prepare the HFP solution of PHBV and electrospin the HFP solution of PHBV on the receiving substrate to obtain a PHBV fiber membrane.

[0052] S30. Composite material is laminated onto the PHBV fiber membrane to obtain a composite fiber membrane.

[0053] This invention utilizes electrospinning of a PHBV HFP solution on a substrate to obtain a hierarchical fiber membrane with coexisting nano- and micron-sized PHBV fibers. This membrane achieves a PM0.3 filtration efficiency exceeding 90%, and since PHBV is a bio-based material, it degrades rapidly. By combining the successfully prepared hierarchical PHBV fiber membrane with a substrate and a face material to form a three-layer sandwich structure, a highly efficient, low-resistance, biodegradable composite fiber membrane with a low risk of electret material failure can be fabricated.

[0054] Further, in step S10, the concentration of PHBV in the HFP solution of PHBV is 4 wt.% to 8 wt.%. At this mass fraction, the nano-PHBV fibers and micron-PHBV fibers obtained by spinning meet the requirements. The mass fraction of PHBV can be 4 wt.%, 4.5 wt.%, 5 wt.%, 5.5 wt.%, 6 wt.%, 6.5 wt.%, 7 wt.%, 7.5 wt.%, or 8 wt.%.

[0055] Further, in step S20, the receiving substrate includes a PVA spunlace nonwoven fabric with a density of 20–30 g / m³. 2 At this density, the composite fiber membrane exhibits superior mechanical properties. The density of PVA spunlace nonwoven fabric can reach 20 g / m³. 2 22g / m 2 24g / m 2 26g / m 2 28g / m 2 30g / m 2 .

[0056] In step S20, the receiving substrate may further include PLA nonwoven fabric, the density of which is 25-35 g / m³. 2 At this density, the composite fiber membrane exhibits superior mechanical properties. The density of PLA nonwoven fabric can be 25 g / m³. 2 26g / m 2 27g / m 2 28g / m 2 29g / m 2 30g / m 2 .

[0057] In step S20, the receiving substrate may also include chitosan nonwoven fabric, the density of which is 30-40 g / m³. 2 At this density, the composite fiber membrane exhibits superior mechanical properties. The density of chitosan nonwoven fabric can reach 30 g / m³. 2 32g / m 2 34g / m 2 36g / m 2 38g / m 2 40g / m 2 .

[0058] Optionally, in step S20, the humidity during electrospinning is 60% to 95% RH; at this humidity level, the spinning efficiency is better. The humidity during electrospinning can be 60% RH, 65% RH, 70% RH, 75% RH, 80% RH, 85% RH, 90% RH, or 95% RH.

[0059] Optionally, in step S20, the electrospinning voltage is 15-20kV, at which the spinning efficiency is better. The electrospinning voltage can be 15kV, 16kV, 17kV, 18kV, 19kV, or 20kV.

[0060] Optionally, in step S20, the spinning distance of electrospinning is 15-30 cm, at which spinning efficiency is better. The spinning distance of electrospinning can be 15 cm, 20 cm, 25 cm, or 30 cm.

[0061] Optionally, in step S20, the feed rate of electrospinning is 1–2 mL / h, at which the spinning efficiency is better. The feed rate of electrospinning can be 1 mL / h, 1.2 mL / h, 1.4 mL / h, 1.6 mL / h, 1.8 mL / h, or 2 mL / h.

[0062] The present invention also proposes a medical protective product, including the aforementioned composite fiber membrane. The medical protective product has all the technical solutions of the composite fiber membrane, and therefore also has all the beneficial effects brought about by the above technical solutions, which will not be elaborated here.

[0063] Furthermore, the medical protective equipment includes masks. These masks have a PM0.3 filtration efficiency of over 90%, effectively isolating most airborne particulate pollutants and the viruses carried by these pollutants, providing effective health protection for the human body. Moreover, all materials used in these masks are biodegradable, capable of complete degradation in the natural environment, thus contributing to the protection of the ecological environment.

[0064] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0065] Example 1

[0066] Using 25 g / m² PVA spunlace nonwoven fabric as the receiving substrate and 5.5% wt PHBV / HFP solution as the spinning precursor solution, spinning was carried out under the conditions of 90% RH, spinning voltage of 18 kV, spinning distance of 30 cm, and feed rate of 0.5 mL / h. The resulting PHBV hierarchical structure membrane had a PHBV nanofiber volume ratio of 60%. A layer of PVA nonwoven fabric was then laminated onto the PHBV-PVA composite fiber membrane to form a... Figure 1 The PVA-PHBV-PVA three-layer sandwich composite fiber membrane shown can achieve a filtration efficiency of over 90% for 0.3μm sodium chloride particles.

[0067] Example 2

[0068] Using 30 g / m² PLA nonwoven fabric as the receiving substrate and 6 wt.% PHBV / HFP solution as the spinning precursor solution, spinning was performed under the conditions of 95% RH, spinning voltage of 20 kV, spinning distance of 20 cm, and feed rate of 1 mL / h. The resulting PHBV hierarchical structure membrane had a PHBV nanofiber volume ratio of 75%. Figure 2 The PLA-PHBV-PLA three-layer composite fiber membrane shown can achieve a filtration efficiency of over 90% for 0.3μm sodium chloride particles.

[0069] Example 3

[0070] Using release paper as the receiving substrate and a 5 wt.% PHBV / HFP solution as the spinning precursor solution, spinning was performed under the conditions of 70% RH, a spinning voltage of 17 kV, a spinning distance of 18 cm, and a feed rate of 1 mL / h. The resulting PHBV hierarchical structure membrane had a PHBV nanofiber volume ratio of 76%. Subsequently, PLA was used to prepare the membrane as shown in the figure. Figure 3 The PHBV hierarchical structure membrane shown is composited to prepare a PLA-PHBV-PLA three-layer composite fiber membrane, which can achieve a filtration efficiency of over 90% for 0.3μm sodium chloride particles.

[0071] Example 4

[0072] Using 35 g / m² chitosan nonwoven fabric as the receiving substrate and 5.5 wt.% PHBV / HFP solution as the spinning precursor solution, spinning was performed under the conditions of 60% RH, spinning voltage of 17 kV, spinning distance of 17.5 cm, and feed rate of 1 mL / h. The resulting PHBV hierarchical structure membrane had a PHBV nanofiber volume ratio of 80%. Figure 4 The chitosan-PHBV-chitosan three-layer composite fiber membrane shown can achieve a filtration efficiency of over 90% for 0.3μm sodium chloride particles.

[0073] Example 5

[0074] Using 32 g / m² chitosan nonwoven fabric as the receiving substrate and 8 wt.% PHBV / HFP solution as the spinning precursor solution, spinning was carried out under the conditions of 95% RH humidity, 20 kV spinning voltage, 30 cm spinning distance, and 2 mL / h feed rate. The volume ratio of nano-PHBV fibers in the prepared PHBV hierarchical structure membrane was 80%. The filtration efficiency of the prepared chitosan-PHBV-chitosan three-layer composite fiber membrane for 0.3 μm sodium chloride particles reached over 90%.

[0075] Comparative Example 1

[0076] Comparative Example 1 is the same as Example 1 except that the PHBV fiber membrane does not contain nano PHBV fiber membrane.

[0077] Since Comparative Example 1 does not contain a nano-PHBV fiber membrane, its filtration efficiency for 0.3-micron sodium chloride particles is relatively low.

[0078] Comparative Example 2

[0079] Comparative Example 2 is the same as Example 1 except that it does not contain micron-sized PHBV fiber membranes.

[0080] Since Comparative Example 2 does not contain a micron-sized PHBV fiber membrane, its mechanical properties are poor; lacking protection, the product is extremely easy to damage; and because the product itself carries a strong static charge, the PHBV membrane is prone to curling without substrate support, making it difficult to use.

[0081] Performance testing

[0082] The volume percentage of nano-PHBV fibers was measured using a grid method, which involves taking a scanning electron microscope (SEM) image at 10,000x magnification, dividing it into multiple squares, and using the number of small squares containing nano-PHBV fibers divided by the total number of squares as the volume percentage of nano-PHBV fibers.

[0083] The composite fiber membranes prepared in Examples 1-5 and Comparative Examples 1-2 of this invention were subjected to filtration tests for 0.3-micron sodium chloride particles. Gas filtration efficiency and resistance (pressure drop at a height of millimeters of water column) were tested. NaCl aerosol was used as the filter medium. The nano-PHBV fiber membrane, along with the receiving substrate, was tested with an effective area of ​​100 cm² and an aerosol flow rate of 95 ± 0.2 / min. The filtration efficiency for 0.3 μm particles was measured, and the performance test values ​​are shown in Table 1.

[0084] Table 1. Test results of composite fiber membrane filtration performance

[0085]

[0086] As shown in Table 1, the composite fiber membranes provided in Examples 1-5 of this invention exhibit better filtration performance at 0.3 μm (%) than those in Comparative Examples 1-2, achieving filtration efficiencies of over 90%. However, Comparative Example 1, lacking a nano-PHBV fiber membrane, has a lower filtration efficiency for 0.3 μm sodium chloride particles. Comparative Example 2, lacking a micron-sized PHBV fiber membrane, exhibits poor mechanical properties.

[0087] In summary, the technical solution provided by this invention includes a PHBV fiber membrane with a hierarchical structure comprising both nano- and micro-sized PHBV fibers. Its PM0.3 filtration efficiency can reach over 90%, and PHBV is a bio-based material with a rapid degradation rate. By combining the successfully prepared PHBV hierarchical fiber membrane with a substrate and a face material to form a three-layer sandwich structure, a highly efficient, low-resistance, biodegradable composite fiber membrane with an electret material that is less prone to failure can be prepared.

[0088] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A composite fiber membrane, characterized by, The membrane comprises, from bottom to top, a substrate, a PHBV fiber membrane, and a face material. The PHBV fiber membrane includes nano-PHBV fibers and micro-PHBV fibers, wherein the nano-PHBV fibers and the micro-PHBV fibers coexist in a hierarchical fiber membrane structure. The diameter of the nano-PHBV fibers is less than or equal to 50 nm, and the diameter of the micro-PHBV fibers is 2 to 10 μm. The volume ratio of the nano-PHBV fibers to the micro-PHBV fibers is (1.5 to 4):

1.

2. The composite fiber film according to claim 1, wherein The thickness of the PHBV fiber membrane is 50~200μm.

3. The composite fiber membrane as described in claim 1, characterized in that, The substrate material includes any one of PVA spunlace nonwoven fabric, PLA nonwoven fabric, chitosan nonwoven fabric, and release paper; and / or, The material of the face material includes any one of PVA spunlace nonwoven fabric, PLA nonwoven fabric, chitosan nonwoven fabric, and release paper.

4. The production method of a composite fiber membrane according to any one of claims 1 to 3, characterized by, Includes the following steps: S10, Provide a receiving base; S20. Prepare the HFP solution of PHBV and electrospin the HFP solution of PHBV on the receiving substrate to obtain a PHBV fiber membrane. S30. Composite material is laminated onto the PHBV fiber membrane to obtain a composite fiber membrane.

5. The method for producing a composite fiber membrane according to claim 4, wherein In step S10, the mass fraction of PHBV in the HFP solution of PHBV is 4wt%~8wt%.

6. The method for producing a composite fiber membrane according to claim 4, wherein In step S20, The receiving substrate includes PVA spunlace nonwoven fabric with a density of 20~30 g / m³. 2 ;or, The receiving substrate comprises a PLA nonwoven fabric, the density of the PLA nonwoven fabric is 25-35 g / m 2 ; or, The receiving substrate comprises a chitosan nonwoven fabric, the density of the chitosan nonwoven fabric is 30-40 g / m 2 .

7. The production method of the composite fiber membrane according to claim 4, wherein In step S20, The humidity range for electrospinning is 60%RH~95%RH; and / or, The voltage for electrospinning is 15~20kV; and / or, The spinning distance in electrospinning is 15~30cm; and / or, The feed rate for electrospinning is 1~2 mL / h.

8. A medical protective article, characterized in that, Includes the composite fiber membrane as described in any one of claims 1 to 3.

9. The medical protective article of claim 8, wherein, The medical protective equipment includes face masks.

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