Anaerobic biodegradable non-woven fabric

Abstract

The invention relates to the technical field of biodegradable materials, and discloses an anaerobic biodegradable non-woven fabric, which is composed of the following components by weight: 60-90 parts of modified polycaprolactone; 15 to 30 parts of biological enzyme slow release particles; 5 to 15 parts of hydrophilic polysaccharide; 2-8 parts of a micro-ecological inducer; 10 to 20 parts of a chitosan-lignin cross-linked structure auxiliary agent; the modified polycaprolactone is based on polycaprolactone, hydroxyl groups are introduced in a hydrophilic monomer grafting mode, and the number-average molecular weight of the modified polycaprolactone is 80,000-150,000; the bio-enzyme slow-release particles are prepared by mixing cellulase and protease according to a mass ratio of 1: 1 and embedding the mixture in a composite carrier formed by chitosan and polylactic acid. By constructing a micro-ecological induction synergistic degradation system, the effects of quick response, graded degradation and structural stable release of the material in an anaerobic environment are achieved.

Description

Technical Field

[0001] This invention relates to the field of biodegradable materials technology, specifically to an anaerobic biodegradable nonwoven fabric. Background Technology

[0002] In daily human activities, short-cycle nonwoven materials are widely used in packaging, protection, medical care, agriculture, and other fields. Traditional material disposal methods such as incineration and landfill are not only costly but also pose a risk of environmental accumulation. Especially in closed environments such as wet waste treatment, sanitary landfill, and anaerobic digestion, the effective degradation of materials directly affects system efficiency and ecological burden. Therefore, developing a functional nonwoven fabric that can stably degrade under anaerobic conditions and possesses self-responsive capabilities has become an important research direction driven by practical needs.

[0003] Existing technologies improve the initial degradability of materials by introducing biodegradable polyesters and polysaccharide fillers and controlling fiber fineness and network structure during preparation. These materials exhibit a certain decomposition ability under humid and ventilated conditions, particularly achieving volume reduction in composting environments. Meanwhile, some approaches also improve the environmental performance of materials during use by using biodegradable carriers and natural fillers. These technical routes provide a basic pathway for degradable materials and also reduce post-use environmental residues to some extent.

[0004] However, existing materials typically lack specific response mechanisms to anaerobic environments and cannot effectively identify the surrounding microecological state. Degradation largely depends on oxygen; in a closed environment, it essentially shuts down. While some technologies attempt to add biological agents, their poor stability and disordered distribution make it difficult to establish a hierarchical reaction chain. More importantly, once the internal structure of the material is formed, it lacks dynamic adjustment capabilities, either failing to degrade or collapsing uncontrollably. The surfaces are also mostly hydrophobic, preventing microorganisms from attaching and hindering reactions. These shortcomings make existing solutions ill-suited for complex, anaerobic, and rapidly changing degradation scenarios. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an anaerobic biodegradable nonwoven fabric that solves the problems of slow response, uncontrollable degradation pathways, structural instability, and low interfacial reaction efficiency of existing materials in anaerobic environments.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an anaerobic biodegradable nonwoven fabric, wherein the nonwoven fabric is composed of the following components in parts by weight: Modified polycaprolactone: 60-90 parts, wherein the modified polycaprolactone is a polymer based on polycaprolactone, with hydroxyl, carboxyl, or ester groups introduced by grafting hydrophilic monomers. The number-average molecular weight of the modified polycaprolactone is 80,000-150,000. Modified polycaprolactone serves as a fiber matrix and is the main material for constructing nonwoven fabric structures and carrying multifunctional factors. The polar groups introduced into the modified structure can act as degradation initiation sites, providing local activation sites for microorganisms under anaerobic conditions and promoting polymer chain breakage under non-inoculation conditions. Furthermore, the block structure of the grafted monomers may also act as an auxiliary segment for small molecule release, enhancing the initiation ability of the initial decomposition rate.

[0007] Bio-enzyme sustained-release particles: 15-30 parts. These particles are prepared by spray drying a mixture of cellulase and protease at a 1:1 mass ratio, encapsulating the mixture in a composite carrier formed from chitosan and polylactic acid. The particle size range is 5-30 micrometers. The bio-enzyme sustained-release particles contain a cellulase and protease composite system, encapsulated through a polysaccharide-ester composite structure. The particle size is set in the micrometer range to facilitate uniform embedding into the nonwoven fiber web during melt dispersion. After material use, these particles gradually release the encapsulated enzymes upon contact with moisture, temperature, or bio-hormonal signals, achieving selective cleavage of surrounding structures.

[0008] Hydrophilic polysaccharides: 5-15 parts, selected from fermentable and degradable natural polysaccharides, including β-glucan and inulin. Their main function in the material is to regulate the hydrophilicity of the microenvironment and provide recognizable degradation substrates. In anaerobic environments, hydrophilic polysaccharides act as microbial substrates, inducing local microbial colonization and initial metabolism. Simultaneously, the swelling of polysaccharide segments upon contact with water helps to relax the internal structure, providing microscopic channels for bio-enzymes and microorganisms to penetrate the fabric. They can serve as targeted degradation targets in the initial stages of slow-release enzyme reactions, thereby activating the enzyme system's synergistic reaction chain.

[0009] Microbial inducing agent: 2-8 parts. The microbial inducing agent is a signal peptide extracted by fermentation of Bacillus spp. microorganisms. The inducing agent is added to the composition in the form of freeze-dried powder and is not chemically modified before blending with the polymer. The microbial inducing agent is derived from the fermentation products of Bacillus spp. microorganisms, and its main components are signal peptides or their oligomeric derivatives. It is designed to stimulate the activity of potential anaerobic microbial communities in the environment under no-inoculation conditions. Its mechanism of action is not to directly participate in degradation, but to induce indigenous microorganisms to express relevant enzymes by releasing signal molecules, thereby realizing the endogenous activation process of the local anaerobic degradation system. This activation method is delayed and controllable, and is more suitable for the microbial succession process in real complex environments.

[0010] Chitosan-lignin crosslinking structural aid: 10-20 parts. This chitosan-lignin crosslinking structural aid is formed by the reaction of chitosan and alkali-treated lignin in the presence of a crosslinking agent, which is either glutaraldehyde or epichlorohydrin. The crosslinking reaction is carried out at a pH of 4.5-6.5 and a temperature of 30-50℃. The chitosan-lignin crosslinking structural aid, formed by chitosan and alkali-treated lignin under the action of a crosslinking agent, possesses the characteristics of a natural polymer network. Its presence not only provides mechanical reinforcement to the fiber but also forms a porous distribution structure, facilitating the subsequent transfer of moisture, gas, and biological factors. The chitosan structure is easily degraded by proteases, while the lignin fragments have a certain degree of non-hydrolyzability. The degradation sequence of the crosslinked regions can control the responsiveness of the internal structure. This network, along with the slow-release particles, forms a "structural constraint / release induction" system, allowing the nonwoven fabric to gradually loosen from the surface in an anaerobic microenvironment.

[0011] This invention also provides a method for preparing anaerobic biodegradable nonwoven fabric, comprising the following steps: S1. Prepare the composition by weighing and premixing the modified polycaprolactone, bio-enzyme sustained-release particles, hydrophilic polysaccharide, microecological inducer and chitosan-lignin crosslinking structural aid according to the weight ratio. S2. The above mixture is melt-blended at a temperature of 150-180℃, with the stirring speed controlled at 60-100 rpm and the blending time at 10-15 minutes, in order to form a uniform melt. S3. After blending, the uniform melt is molded by meltblowing, wherein the meltblowing temperature is set to 160-190℃, the die temperature is 180-210℃, and the distance between the fiber spraying and collection is controlled at 10-20 cm. S4. Perform plasma surface treatment on the obtained nonwoven fabric molding. The treatment voltage is 10-20 kV, the frequency is 10-25 kHz, and the treatment time is controlled between 30-60 seconds to change the surface state of the material. S5. Store the treated nonwoven fabric under conditions of relative humidity less than or equal to 50% and temperature of 15-35℃.

[0012] Preferably, in step S2, the melt blending treatment of the above mixture includes the following steps: Add the weighed components sequentially to a blending device preheated to 150-180℃, stirring while adding. The stirring speed is controlled at 60-100 rpm. Continuously blend under sealed conditions for 10-15 minutes until the material presents a uniform and viscous state. The melt blending step, as a crucial material integration process, plays a decisive role in the uniform dispersion of functional components and the pre-assembly effect of the structure. The weighed components are sequentially added to the blending equipment, and stirring is performed while the temperature is raised to a predetermined level. During this process, stirring not only promotes the thermal melting and softening of the materials but also accelerates the uniformity of the surface coating matrix of the functional particles through shearing action. The blended system is maintained in a closed state for a set time to allow the modified polycaprolactone, chitosan lignin-based additives, and slow-release particles to fully integrate.

[0013] Preferably, in step S3, the uniform melt is formed by melt-blowing, which includes the following steps: The melt is introduced into the meltblown die and extruded while the die temperature is maintained at 180-210°C. It is then stretched by a hot airflow at 160-190°C, and the fibers are deposited onto the surface of the receiving device through a path of 10-20 cm to form a nonwoven structure. Meltblowing, as the primary method for constructing nonwoven fabrics, is not only a structural shaping process but also a spatial orientation stage for realizing functional distribution. In this step, a pre-formed uniform melt is extruded under temperature-controlled conditions at the die head and traction and atomization are achieved with the help of hot air flow, thereby forming fine, continuous fibers. These fibers are deposited onto the surface of the receiving device within a specified distance, forming a stable nonwoven web structure.

[0014] This molding process rapidly cools and shapes the fibers, maintaining the slow-release particles and microecological factors embedded in the matrix in a predetermined spatial distribution. Due to the controllable porosity and surface energy characteristics of the fibers themselves, this distribution structure facilitates regional activation of subsequent functions. The stacking pattern between fibers also provides initial conditions for water penetration and biological pathway diffusion during the degradation process.

[0015] Preferably, in step S4, the plasma surface treatment of the obtained nonwoven fabric includes the following steps: flattening the nonwoven fabric on the treatment platform, adjusting the voltage to 10-20 kV and the frequency to 10-25 kHz, performing surface treatment through a 5-10 mm gap between the electrode head and the fabric surface, and setting the treatment time to 30-60 seconds. After the nonwoven fabric structure is formed, a plasma surface treatment process is introduced. This process uses a low-temperature plasma source with specific voltage and frequency to modify the fabric surface non-thermally, using high-energy active particles to transform surface functional groups, increase roughness, and enhance local polarity.

[0016] This treatment does not alter the main structure of the fiber matrix, but introduces more reaction sites at the molecular level, which helps improve microbial recognition ability and water vapor exchange efficiency. More importantly, plasma modification may also activate the response chain of some microbial inducing factors, enabling them to induce chemotactic aggregation and functional expression of local microorganisms in a natural environment without external inoculation.

[0017] Preferably, in step S5, storing the treated nonwoven fabric under conditions of relative humidity less than or equal to 50% and temperature of 15-35°C includes the following steps: After cutting the non-woven fabric, place it in a sealed packaging bag and store it in an environment with controlled temperature and humidity, away from light, and keep the storage space ventilated and dry. The storage conditions for the formed nonwoven fabric have also been clearly defined, which are based not only on the physical stability of the material, but also on the maintenance of the activity of functional factors. By cutting and packaging the treated nonwoven fabric and storing it in a temperature and humidity controlled environment, the premature release or degradation of microecological inducing factors or slow-release enzyme systems can be effectively prevented, ensuring that it retains its preset response potential when used.

[0018] This invention provides an anaerobic biodegradable nonwoven fabric. It has the following beneficial effects: 1. This invention activates natural microbial communities in the environment by embedding microbial induction components within the material, constructing a material system that can self-trigger a response without exogenous inoculation. Compared to existing methods that rely on the addition or cultivation of microorganisms, this avoids the problems of operational complexity and inconsistent responses, and improves the environmental adaptability and deployment convenience of the material.

[0019] 2. By utilizing the synergistic structure between bio-enzyme slow-release particles, polysaccharides, and structural additives, the material of this invention can achieve a stratified response of functional factors in the early stages of degradation. The problems of discrete distribution of enzymes and structural components and discontinuous reaction breakpoints in traditional materials are effectively avoided here, solving the bottlenecks of low initial degradation efficiency and unclear pathways.

[0020] 3. By introducing a chitosan-lignin crosslinking network as a structural regulation unit, the material possesses the dual function of "maintaining structure and guiding degradation." Conventional additives mostly focus on reinforcement or filling, lacking controllable degradation. This design achieves the coupling of structural stability and degradability, overcoming the technical contradiction of their incompatibility.

[0021] 4. Through end-of-pipe plasma treatment, this invention imparts higher energy states and polarity to the material surface, significantly improving the contact efficiency between moisture and microorganisms in the degradation environment. Existing solutions generally exhibit strong surface inertness, making it difficult to quickly establish an interfacial response chain. This solution enables the reaction to take effect rapidly on the fabric surface, resulting in a faster response and a clearer pathway. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the preparation method of the present invention. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0024] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0025] Please see the appendix Figure 1 : Example 1: Component ratio (by weight): Modified polycaprolactone: 75 parts, bio-enzyme sustained-release particles: 22 parts, hydrophilic polysaccharide: 10 parts, microecological inducer: 5 parts, chitosan-lignin cross-linking structural aid: 15 parts.

[0026] Preparation steps: The mixture is fed into a twin-screw mixer preheated to 165°C, and the stirring speed is controlled at 80 rpm. The mixture is then mixed in a closed system for 12 minutes until a homogeneous melt system is formed.

[0027] The resulting melt is introduced into a meltblown device, the die temperature is set to 195℃, the hot air temperature is set to 175℃, and the distance between the sprayed fiber and the collecting device is set to 15cm. After being thermally stretched, the fiber is randomly deposited to form a nonwoven fabric material.

[0028] After being formed, the fabric is flattened and enters the plasma treatment device. The voltage is set to 15kV, the frequency to 20kHz, the distance between the electrode and the fabric surface to 7mm, and the treatment time is controlled to 45 seconds.

[0029] After processing, cut the non-woven fabric and place it in a sealed packaging bag. Then, transfer it to a constant temperature and dry environment with a temperature of 25°C and a relative humidity of 45% for storage, and keep it away from light.

[0030] Example 2: Component ratio (by weight): Modified polycaprolactone: 90 parts, bio-enzyme sustained-release particles: 30 parts, hydrophilic polysaccharide: 15 parts, microecological inducer: 8 parts, chitosan-lignin cross-linking structural aid: 20 parts.

[0031] Preparation steps: The mixture is fed into a blending apparatus preheated to 180°C, and the stirring speed is set to 100 rpm. The mixture is then blended for 15 minutes under closed conditions to form a high-viscosity, homogeneous melt.

[0032] The melt is introduced into the meltblown die head, the die head temperature is set to 210℃, the hot air temperature is 190℃, and the vertical distance from the fiber sprayed to the receiving surface is controlled at 20cm. The resulting fiber network is stably deposited under the action of wind.

[0033] The resulting nonwoven fabric was then sent to a plasma treatment device for processing. The treatment voltage was 20kV, the frequency was 25kHz, the distance between the electrode head and the fabric surface was 10mm, and the processing time was set to 60 seconds.

[0034] After processing, the materials are cut and packaged, and stored in an indoor environment with a temperature not exceeding 35°C and a relative humidity not exceeding 50%, away from light.

[0035] Example 3: Component ratio (by weight): Modified polycaprolactone: 60 parts, bio-enzyme sustained-release particles: 15 parts, hydrophilic polysaccharide: 5 parts, microecological inducer: 2 parts, chitosan-lignin cross-linking structural aid: 10 parts.

[0036] Preparation steps: The mixture is added to a melt blending device heated to 150°C, the stirring speed is set to 60 rpm, and the blending time is 10 minutes to form a low-viscosity fluid melt.

[0037] The melt is extruded through a meltblown device with a die temperature of 180℃, and then stretched using hot air at 160℃. The fiber drop distance is controlled at 10cm to form a nonwoven layer with high density.

[0038] Immediately after molding, plasma surface treatment is performed with a voltage of 10kV, a frequency of 10kHz, a distance of 5mm between the electrode head and the fabric surface, and a treatment time of 30 seconds.

[0039] After processing, the non-woven fabric is packaged and stored in a dry environment with a temperature not lower than 15℃ and a relative humidity not higher than 50%.

[0040] Comparative Example 1: Compared with Example 1, the difference is that no microbial inducer was added, resulting in a slow start-up of the overall degradation response; Comparative Example 2: Compared with Example 1, the difference is that no bio-enzyme slow-release particles were added, which made it difficult for the structural aids and polysaccharide components to be effectively broken down in the initial degradation stage; Comparative Example 3: Compared with Example 1, the difference is that no chitosan-lignin crosslinking structural aid was added, while all other aspects are the same; this resulted in the loss of the degradation aid function of the structure being gradually released through selective protease reaction.

[0041] Experiment 1: Experimental objective: By simulating an anaerobic environment, this experiment aims to test the time required for Example 1 and Comparative Example 1 to develop initial structural responses (edge ​​warping, softening, and cracking) after exposure, and to determine the material's response initiation efficiency to an anaerobic environment.

[0042] Experimental steps: Sample preparation: The nonwoven fabric samples from Example 1 and Comparative Example 1 were cut into 30mm×30mm square sheets, and three parallel samples were set up for each group.

[0043] Environmental simulation: Use a 500mL anaerobic culture flask and add 200mL of anaerobic simulation solution (formulation: phosphate buffer + tryptone + trace salt solution, pH≈7.2).

[0044] A small amount of activated anaerobic sludge (derived from the municipal wastewater treatment system) was introduced as a background microbial source.

[0045] The gas inside the bottle was replaced with nitrogen to maintain dissolved oxygen in the solution at <0.1 mg / L.

[0046] Sample placement and sealing: The samples were placed into different bottles, labeled and numbered, the bottle mouths were sealed, and the bottles were placed in a constant temperature shaking incubator at a temperature of 37°C and a shaking rate of 50 rpm.

[0047] Observation and Recording: The sample status should be observed every 6 hours.

[0048] Record the time point at which the first visible structural response appears (such as edge lifting, slight expansion, color change, crack propagation, etc.).

[0049] The evaluation metric is "time required for the first response".

[0050] End of cycle: The observation period was set to 72 hours. If there was no response, it was recorded as ">72h" (the experimental results are shown in Table 1).

[0051] Table 1: Comparison of Anaerobic Response Start-up Time From Table 1, we can obtain: Under the standard anaerobic environment set up in this experiment, samples containing microbial inducing components exhibited significantly faster initial response capabilities. This phenomenon indicates that the introduced signaling inducer can actively activate the existing anaerobic microbial community in the environment without exogenous inoculation, inducing it to express specific metabolic enzyme systems, thereby initiating the degradation pathway of hydrolyzable components of the material. In contrast, materials without inducing components showed a delayed response or even no significant change within the set period, indicating that the microbial signaling mechanism plays a crucial initiating role in the material-environment interaction.

[0052] The material's structural design is based on a multi-layered synergistic response. Rapid response depends not only on activation by external microorganisms but also on the accessibility of identifiable structural regions within the material. In samples containing signal-inducing components, microorganisms can more quickly identify and access the hydrophilic components and surface regions of the material, thus initiating a programmed degradation process from the surface inwards. The establishment of this response chain reflects that the material possesses not only static structural stability but also dynamic transformation capabilities triggered by biological signals.

[0053] This experiment further validates the organic unity between environmental adaptability and response efficiency in the constructed system. By embedding the response factor into the material system, not only is dependence on exogenous additives avoided, but a direct coupling relationship is also established between the degradation behavior and the surrounding environmental conditions. The resulting material system can adaptively adjust its degradation behavior according to the composition of the environmental microecology and activation conditions in anaerobic scenarios, demonstrating a highly integrated design logic and supporting the predictability and engineering applicability of the material in different degradation scenarios.

[0054] Experiment 2: Experimental objective: To verify whether the material can effectively initiate the synergistic release of internal structural factors in the early stage of degradation, demonstrating stratified degradation characteristics, with particular attention to the impact of the bioenzyme embedding mechanism on the initial cleavage efficiency of chitosan and polysaccharide components.

[0055] Experimental steps: Sample preparation: The nonwoven fabric materials of Example 1 and Comparative Example 2 (without bio-enzyme slow-release particles) were cut into 20mm×20mm square pieces, and three parallel samples were prepared for each material.

[0056] Pre-treatment: Each sample was placed in 10 mL of simulated anaerobic solution (sterile phosphate buffer, pH 7.0) and left to stand at 25°C for 2 hours to ensure material hydration and activate the material surface state.

[0057] Anaerobic culture: Transfer the hydrated sample to a 50mL sealed culture bottle, add fresh anaerobic mass solution (containing trace amounts of yeast extract, glucose, vitamins and environmental flora), and place it in a 37℃ constant temperature anaerobic shaking incubator, gently shaking (60rpm) every hour to simulate mild hydrodynamics.

[0058] Structural Change Observation and Recording: At time points of 6h, 12h, 24h, 36h, and 48h after the start of degradation, observe the changes in the appearance of the material and record whether phenomena such as edge delamination, internal cracks, structural softening, and local peeling occur.

[0059] Synergistic cleavage criteria: When multiple structural factors (such as sugars and structural additives) in a sample exhibit synchronous release, exfoliation, or fracturing changes, it is recorded as "synergistic cleavage characteristics appear"; if only the surface structure softens or the edges change slightly, it is not included in the effective response (experimental results are shown in Table 2).

[0060] Table 2: Observation timeline of structural co-fracture From Table 2, we can obtain: Under the experimental conditions, the material containing the slow-release enzyme component exhibited significant structural chromatographic changes in the early stages of degradation, indicating that a synergistic reaction pathway capable of activating the polysaccharide and structural aid components had been formed within the material. This phenomenon demonstrates that the designed enzyme release mechanism not only maintains activity in a hydrated environment but also penetrates into the internal structure, orderly cleaving pre-defined identifiable structural domains within the material, thus providing a pre-channel for subsequent structural disintegration.

[0061] The introduction of the enzyme-release mechanism enables the rapid recognition and response of polysaccharide components and cross-linked structural regions originally distributed in the matrix. The degradation process transforms from a single surface swelling to a multi-level simultaneous reaction, demonstrating a systematic response capability. This structural loosening characteristic indicates that the material has established a synergistic degradation triggering mechanism both internally and externally in its overall structure. The controllable coupling design of the enzyme-target structure is of core significance for initiating the reaction chain.

[0062] In contrast, materials without this functional component maintained a relatively intact morphology within the same time period and did not exhibit multi-component linkage reaction characteristics, indicating that the degradation pathway was restricted and it was difficult to achieve the synergistic release of structural factors. The overall experiment verified that achieving staged structural rupture through functional embedded design is a key foundation for the controllability and synergy of material degradation, and also directly supports the construction logic of the system response chain.

[0063] Experiment 3: Experimental objective: By continuously observing the structural evolution of materials under anaerobic conditions, to evaluate whether they exhibit good morphological stability and orderly degradation characteristics during the degradation process, with particular attention to whether they exhibit a phased behavior of "first surface dissociation - middle layer slow release - deep layer decomposition".

[0064] Experimental steps: Sample preparation: The nonwoven fabric materials of Example 1 and Comparative Example 3 (without cross-linking structural aids) were each cut into 25mm×25mm square pieces, and three parallel samples of each material were prepared and numbered.

[0065] Anaerobic degradation system setup: Add 70 mL of anaerobic basic culture medium to a 100 mL sealed glass reaction flask; One sample tablet was placed in each bottle; The culture medium was inoculated with active anaerobic bacteria (containing cellulose-decomposing bacteria and protease-expressing bacteria); Place it in an anaerobic incubator and control the temperature at 37℃.

[0066] Periodic observation and photographic recording: In the degradation system, samples were removed and observed every 12 hours until the end of 72 hours. Observations included: Does the material maintain its overall structure? Whether there are stage-specific changes such as edge damage, mid-layer delamination, or overall collapse; If a "rapid overall collapse" occurs, record the time when it first happens.

[0067] Evaluation indicators: If a material can maintain structural continuity for more than 36 hours and the degradation process is clearly stratified, it is considered to have good procedural properties. If widespread cracking or structural collapse occurs within 24 hours, it is considered to lack stable degradation regulation capacity (experimental results are shown in Table 3).

[0068] Table 3: Observation of structural evolution during degradation process From Table 3, we can obtain: In this experiment, samples with cross-linking agents exhibited significant structural stability and phased evolution characteristics during degradation, indicating that these agents not only provide support during molding but also play a role in structural slow-release regulation in the early stages of degradation. The material gradually disintegrated from the surface layer within 24 to 36 hours, while the middle layer maintained a certain degree of integrity. The overall degradation process showed an orderly progression of morphological changes from the outside in. This "slow-release pyrolysis" phenomenon demonstrates that the structural design of the material has the ability to control the reaction pathway and rate, effectively preventing disordered disintegration or structural runaway.

[0069] The cross-linked network structure employed is not completely inert in the reaction environment. Instead, it achieves the release of degradable properties at specific sites through enzyme-mediated selective recognition and cleavage. The network's role is not to completely resist degradation, but to provide support and deformation regulation at specific stages, giving the material the functional advantage of "shape preservation and controlled deconstruction." The layered collapse and delayed framework disintegration observed in experiments demonstrate the mechanism of staged recognition and gradual cleavage of cross-linked regions, effectively extending the structural integrity period of the material during degradation.

[0070] The control materials without this structural additive generally experienced overall instability within a short period, with rapid structural collapse and failure to maintain proper morphological continuity, indicating a lack of internal structural traction and reaction rhythm control mechanisms. This difference further illustrates that the introduction of the structural additive not only improves the material's molding performance, but more importantly, it constructs an inherent sequential logic between "support-response-release" in the degradation system, making it a core component for achieving multi-stage response and stability matching in materials.

[0071] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An anaerobic biodegradable nonwoven fabric, characterized by, The non-woven fabric is composed of the following components by weight: Modified polycaprolactone: 60-90 parts; Biological enzyme sustained-release particles: 15-30 parts; Hydrophilic polysaccharide: 5-15 parts; Microecological inducer: 2-8 parts; Chitosan-lignin cross-linked structure aid: 10-20 parts.

2. The anaerobic biodegradable nonwoven fabric according to claim 1, characterized by The modified polycaprolactone is based on polycaprolactone, which introduces hydroxyl and carboxyl groups by grafting hydrophilic monomers. The number average molecular weight of the modified polycaprolactone is 80,000-150,000.

3. The anaerobic biodegradable nonwoven fabric according to claim 1, characterized by The biological enzyme sustained-release particles are particles prepared by embedding cellulase and protease mixed at a mass ratio of 1:1 in a composite carrier formed by chitosan and polylactic acid, and then spray drying. The particle size range is 5-30 microns.

4. The anaerobic biodegradable nonwoven fabric according to claim 1, wherein The microecological inducer is a signal polypeptide extracted by fermentation of Paenibacillus-like microorganisms. The inducer is added to the composition in the form of freeze-dried powder without chemical modification before blending with the polymer.

5. The anaerobic biodegradable nonwoven fabric according to claim 1, wherein The chitosan-lignin cross-linked structure aid is formed by the reaction of chitosan and alkali-treated lignin in the presence of a cross-linking agent. The cross-linking agent used is one of glutaraldehyde and epichlorohydrin. The cross-linking reaction is carried out at a pH of 4.5-6.5 and a temperature of 30-50°C.

6. A process for the preparation of an anaerobic biodegradable nonwoven fabric according to any one of claims 1 to 5, characterized in that, The following steps are included: S1, preparing the composition, weighing and pre-mixing the modified polycaprolactone, biological enzyme sustained-release particles, hydrophilic polysaccharide, microecological inducer and chitosan-lignin cross-linked structure aid according to the weight ratio; S2, melt blending the mixture at a temperature of 150-180°C, with stirring speed controlled at 60-100 rpm, and blending time of 10-15 minutes to form a uniform melt; S3, after blending, the uniform melt is formed by melt blowing, with melt blowing temperature set at 160-190°C, die temperature at 180-210°C, and distance between fiber ejection and collection controlled at 10-20 cm; S4, plasma surface treatment of the obtained non-woven fabric forming, with treatment voltage of 10-20 kV, frequency of 10-25 kHz, and treatment time controlled between 30-60 seconds to change the material surface state; S5, storing the treated non-woven fabric under conditions of relative humidity less than or equal to 50% and temperature of 15-35°C.

7. The anaerobic biodegradable nonwoven fabric according to claim 6, wherein In the S2 step, the melt blending of the mixture includes the following steps: The weighed components are added to the preheated blending equipment at 150-180°C, and stirred while adding, with stirring speed controlled at 60-100 rpm. The blending is continued under closed conditions for 10-15 minutes until the material presents a uniform sticky state.

8. The anaerobic biodegradable nonwoven fabric according to claim 6, wherein In the S3 step, the uniform melt is formed by melt blowing, including the following steps: The melt is introduced into the melt blowing die, extruded at a die temperature maintained at 180-210°C, and drawn by hot air flow at a temperature of 160-190°C. The fibers are deposited on the surface of the receiving device through a path of 10-20 cm to form a non-woven structure.

9. The anaerobic biodegradable nonwoven fabric according to claim 6, wherein The plasma surface treatment of the obtained non-woven fabric forming product in the S4 step comprises the following steps: The non-woven fabric is placed flat on a treatment platform, the voltage is adjusted to 10-20 kV, the frequency is 10-25 kHz, the surface treatment is performed through a 5-10 mm gap between the electrode head and the fabric surface, and the treatment time is set to 30-60 seconds.

10. The anaerobic biodegradable nonwoven fabric according to claim 6, characterized by In the S5 step, the treated non-woven fabric is stored under the condition that the relative humidity is less than or equal to 50% and the temperature is 15-35°C, which comprises the following steps: After cutting, the non-woven fabric is placed in a sealed packaging bag and stored in a controllable temperature and humidity environment, protected from light, and the storage space is kept ventilated and dry.

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