Degradable polyester nonwoven based on coordination and method for preparing the same

Abstract

This application provides a biodegradable polyester nonwoven fabric based on coordination interaction and its preparation method, belonging to the field of textile materials. The method includes: providing a biodegradable and coordinateable polyester; the biodegradable and coordinateable polyester includes a mixture of biodegradable polyester and a coordination functional composition or a coordination-modified biodegradable polyester; melt-blending and granulating the biodegradable and coordinateable polyester with a metal ion source to obtain a masterbatch; melt-spinning the masterbatch to obtain nascent fibers; web-forming the nascent fibers to obtain a fiber web; impregnating the fiber web in a solution containing a metal ion source for re-coordination, followed by post-treatment to obtain the biodegradable polyester nonwoven fabric based on coordination interaction. Through secondary coordination, the coordination effect is strengthened, improving the performance of the biodegradable polyester nonwoven fabric.

Description

Technical Field

[0001] This application relates to the field of textile materials technology, specifically to a biodegradable polyester nonwoven fabric based on coordination and its preparation method. Background Technology

[0002] Aromatic polyesters, represented by polyethylene terephthalate (PET), possess excellent chemical stability, mechanical strength, and transparency, making them widely used in the fields of synthetic fibers and packaging. However, due to their stable chemical properties, nonwoven materials prepared from PET are difficult to degrade naturally, causing significant environmental pollution. Therefore, utilizing biodegradable materials to prepare nonwoven materials is of great significance. Biodegradable polyesters, in particular, are biodegradable polymers with excellent degradation properties under the action of microorganisms and enzymes, making them ideal raw materials for nonwoven textiles. However, they often suffer from insufficient mechanical strength, poor hydrophilicity, and limited functionality.

[0003] In related technologies, blending modification improves various properties of biodegradable polyesters, but sacrifices the crystallization ability and elongation at break of the biodegradable polyester; chain extension modification has a negative impact on the thermal stability of biodegradable polyesters and increases the risk of gelation; modifying biodegradable polyesters through nanocomposite methods increases production costs, and the dispersion of fillers also becomes a major problem.

[0004] In view of this, it is necessary to design a biodegradable polyester nonwoven fabric based on coordination and its preparation method to solve the above problems. Summary of the Invention

[0005] In view of the technical problems existing in the background art, this application provides a biodegradable polyester nonwoven fabric based on coordination and its preparation method. The preparation method adopts a secondary coordination method to enhance the mechanical properties of biodegradable polyester, improve the stability of biodegradable polyester, and achieve performance improvement of biodegradable polyester.

[0006] To achieve the above objectives, this application proposes a biodegradable polyester nonwoven fabric based on coordination interaction and a method for preparing the same, comprising: Provide biodegradable and coordinable polyesters; biodegradable and coordinable polyesters include mixtures of biodegradable polyesters and coordination functional compositions or coordination-modified biodegradable polyesters; Degradable and coordinable polyester and metal ion source are melt-blended and granulated to obtain masterbatch; The masterbatch is melt-spun to obtain nascent fibers; The nascent fibers are laid into a web to form a fiber web; After impregnating the fiber web with a solution containing a metal ion source for recoordination, a biodegradable polyester nonwoven fabric based on coordination is obtained after post-treatment.

[0007] Furthermore, the biodegradable polyester includes at least one of polylactic acid, polycaprolactone, polyhydroxyalkanoate, and polybutylene succinate; the coordination-modified biodegradable polyester includes PBST polyester modified with imidazole-4,5-dicarboxylic acid.

[0008] Furthermore, the coordination functional composition includes at least one of citric acid, dopamine, chitosan, and 8-hydroxyquinoline.

[0009] Furthermore, the metal ions in the metal ion source include at least one of zinc, copper, silver, iron, and calcium.

[0010] Furthermore, in the mixture of biodegradable polyester and coordination functional composition, the molar ratio of biodegradable polyester and coordination functional composition is 100:(5-20).

[0011] Furthermore, the molar ratio of the biodegradable and coordinable polyester to the metal ion source is 100:(1-10).

[0012] Furthermore, in the solution containing the metal ion source, the mass percentage of the metal ion source is 1%-10%.

[0013] Furthermore, the melt blending temperature is 180℃-200℃.

[0014] Furthermore, when laying the nascent fibers into a web, the forming process includes at least one of meltblown, spunbond, and hot rolling.

[0015] To achieve the above objectives, this application also provides a coordination-based biodegradable polyester nonwoven fabric, which is prepared by the preparation method of coordination-based biodegradable polyester nonwoven fabric of any of the foregoing technical solutions.

[0016] The beneficial effects of this application are as follows: In the technical solution of this application, a biodegradable and coordinateable polyester undergoes a first coordination with metal ions. The atoms in the biodegradable and coordinateable polyester that can coordinate with metal ions are those with strong electronegativity containing lone pairs of electrons. The coordination functional composition can modify the biodegradable polyester by copolymerizing molecular chains with additional coordinating groups (such as carboxyl or pyridyl groups) into the biodegradable polyester backbone, thus adding stronger coordination sites. Metal ions can simultaneously bind to coordination sites from two or more different biodegradable and coordinateable polyester chains. When a metal ion approaches an atom containing a lone pair of electrons on the biodegradable and coordinateable polyester, it forms a coordination relationship with it and redistributes the electron cloud within the adsorbed molecule, thereby activating the molecule and making stable chemical bonds more reactive, facilitating subsequent reactions. As the metal ions connect the molecular chains of the biodegradable and coordinateable polyester layer by layer, a physical cross-linked network is formed, thereby increasing the strength of the biodegradable polyester. A second coordination process is then applied to the biodegradable polyester fiber web. This utilizes the remaining coordination sites because metal ions are unsaturated; that is, after a metal ion coordinates with one set of ligands, there are still vacant sites around it. Therefore, a second type of ligand (metal ion) can be introduced. These new metal ions will occupy the coordination vacancies, achieving secondary coordination. These new metal ions can further improve the performance of the biodegradable polyester. Alternatively, the metal ions can further coordinate with a second metal ion. When the two metal ions are very close, they can synergistically act within the molecular chain of the biodegradable polyester, forming a double-network structure, further improving the performance of the biodegradable polyester. The metal ions introduced through these two coordination processes provide the biodegradable polyester with more properties, increasing its strength and stability.

[0017] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Detailed Implementation

[0018] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the description and claims of this application are intended to cover non-exclusive inclusion.

[0020] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0023] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0024] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are used only to facilitate the description of the embodiments of this application and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0025] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0026] Aromatic polyesters, represented by polyethylene terephthalate (PET), possess excellent chemical stability, mechanical strength, and transparency, making them widely used in the fields of synthetic fibers and packaging. However, due to their stable chemical properties, nonwoven materials prepared from PET are difficult to degrade naturally, causing significant environmental pollution. Therefore, utilizing biodegradable materials to prepare nonwoven materials is of great significance. Biodegradable polyesters, in particular, are biodegradable polymers with excellent degradation properties under the action of microorganisms and enzymes, making them ideal raw materials for nonwoven textiles. However, they often suffer from insufficient mechanical strength, poor hydrophilicity, and limited functionality.

[0027] In related technologies, blending modification improves various properties of biodegradable polyesters, but sacrifices the crystallization ability and elongation at break of the biodegradable polyester; chain extension modification has a negative impact on the thermal stability of biodegradable polyesters and increases the risk of gelation; modifying biodegradable polyesters through nanocomposite methods increases production costs, and the dispersion of fillers also becomes a major problem.

[0028] To address the aforementioned issues, this application proposes a biodegradable polyester nonwoven fabric based on coordination and a method for preparing the same, comprising: providing a biodegradable and coordinateable polyester; the biodegradable and coordinateable polyester includes a mixture of biodegradable polyester and a coordination functional composition or a coordination-modified biodegradable polyester. Degradable and coordinable polyester and metal ion source are melt-blended and granulated to obtain masterbatch; The masterbatch is melt-spun to obtain nascent fibers; The nascent fibers are laid into a web to form a fiber web; After impregnating the fiber web with a solution containing a metal ion source for recoordination, a biodegradable polyester nonwoven fabric based on coordination is obtained after post-treatment.

[0029] In the technical solution of this application, a biodegradable and coordinateable polyester undergoes a first coordination with metal ions. The atoms in the biodegradable and coordinateable polyester that can coordinate with metal ions are those with strong electronegativity containing lone pairs of electrons. The coordination functional composition can modify the biodegradable polyester by copolymerizing molecular chains with additional coordinating groups (such as carboxyl or pyridyl groups) into the biodegradable polyester backbone, thus adding stronger coordination sites. Metal ions can simultaneously bind to coordination sites from two or more different biodegradable and coordinateable polyester chains. When a metal ion approaches an atom containing a lone pair of electrons on the biodegradable and coordinateable polyester, it forms a coordination relationship with it and redistributes the electron cloud within the adsorbed molecule, thereby activating the molecule and making stable chemical bonds more reactive, facilitating subsequent reactions. As the metal ions connect the molecular chains of the biodegradable and coordinateable polyester layer by layer, a physical cross-linked network is formed, thereby increasing the strength of the biodegradable polyester. A second coordination process is then applied to the biodegradable polyester fiber web. This utilizes the remaining coordination sites because metal ions are unsaturated; that is, after a metal ion coordinates with one set of ligands, there are still vacant sites around it. Therefore, a second type of ligand (metal ion) can be introduced. These new metal ions will occupy the coordination vacancies, achieving secondary coordination. These new metal ions can further improve the performance of the biodegradable polyester. Alternatively, the metal ions can further coordinate with a second metal ion. When the two metal ions are very close, they can synergistically act within the molecular chain of the biodegradable polyester, forming a double-network structure, further improving the performance of the biodegradable polyester. The metal ions introduced through these two coordination processes provide the biodegradable polyester with more properties, increasing its strength and stability.

[0030] In summary, the synergistic effect of secondary coordination improves the strength and stability of biodegradable polyesters, thereby enhancing their performance. By selecting secondary coordinated metal ions and utilizing their intrinsic properties, different properties can be provided to biodegradable polyesters.

[0031] In some embodiments, the biodegradable polyester includes at least one of polylactic acid, polycaprolactone, polyhydroxyalkanoate, and polybutylene succinate; the coordination-modified biodegradable polyester includes PBST polyester modified with imidazole-4,5-dicarboxylic acid.

[0032] In this embodiment, polylactic acid (PLA) exhibits good gloss and transparency. The raw material is derived from renewable plant resources, making it environmentally friendly and safe. It also possesses good mechanical strength, is not easily deformed, and has certain antibacterial properties. Polycaprolactone (PCL) exhibits shape memory properties, meaning that after deformation at a specific temperature, it can recover its original shape upon reheating. PCL also has high elongation at break and good flexibility. Polyhydroxyalkanoates (PHA) have multiple degradation pathways and good biocompatibility. Polybutylene succinate (PBST) has a heat distortion temperature reaching 100°C, good heat resistance, and combines strength and toughness. Its low cost effectively controls production costs. Imidazole-4,5-dicarboxylic acid (ICA)-modified PBST polyester is produced by introducing an imidazole ring into the PBST main chain, increasing the polyester's glass transition temperature and thermal decomposition temperature, making it more heat-resistant. The nitrogen atoms and carboxyl groups on the imidazole-4,5-dicarboxylic acid-modified PBST polyester provide more coordination sites. In summary, the materials mentioned above—polylactic acid, polycaprolactone, imidazole-4,5-dicarboxylic acid modified PBST, polyhydroxyalkanoates, and polybutylene succinate—all exhibit good biodegradability and biocompatibility. Furthermore, these polyesters can all undergo conventional processing, resulting in low processing difficulty and reduced production costs. In addition, the properties of these polyesters can be tuned by introducing groups or atoms that facilitate coordination into the main chain, thereby enhancing coordination and improving the performance of biodegradable polyester nonwoven fabrics.

[0033] In some embodiments, the coordination functional composition includes at least one of citric acid, dopamine, chitosan, and 8-hydroxyquinoline.

[0034] In this embodiment, citric acid contains three carboxyl groups and one hydroxyl group, giving it multiple coordination sites. These multiple groups can simultaneously coordinate with metal ions to form a stable cyclic structure. The carboxyl groups are the primary coordination sites, and under alkaline conditions, the hydroxyl groups also participate in coordination, further stabilizing the structure. Dopamine contains catechol and amino groups. The catechol structure improves the adhesion of the polyester and polymerizes into a polydopamine coating under alkaline conditions. Both catechol and amino groups can coordinate with metal ions. Chitosan is a natural polymer with numerous amino and hydroxyl groups on its molecular chain, providing a large number of coordination sites for metal ions. 8-Hydroxyquinoline contains phenolic hydroxyl groups and heterocyclic nitrogen, forming a stable five-membered chelate ring and improving the stability of the coordination with metal ions. In summary, the materials mentioned above—citric acid, dopamine, chitosan, and 8-hydroxyquinoline—all possess abundant electron-donating atoms (oxygen and nitrogen atoms), providing sufficient coordination sites for metal ions. Moreover, these materials have intrinsically different properties, which can provide different properties to polyester nonwoven fabrics and improve the strength of polyester nonwoven fabrics through stable coordination.

[0035] In some embodiments, the metal ions in the metal ion source include at least one of zinc, copper, silver, iron, and calcium.

[0036] In this embodiment, zinc ions exhibit good biocompatibility, are an essential trace element for the human body, are safe and non-toxic, and as a Lewis acid, possess high catalytic activity, enabling efficient coordination with coordination sites in polyester. Copper ions possess redox activity, can efficiently transfer electrons, and also exhibit antibacterial and paramagnetic properties. Silver ions provide broad-spectrum and potent antibacterial activity and are relatively inert, remaining stable in air. Iron ions are ferromagnetic, abundant in the Earth's crust, and inexpensive. Calcium ions have good biocompatibility, strong ion exchange capacity, and readily coordinate with metal ions.

[0037] In some embodiments, the molar ratio of the biodegradable polyester to the coordination functional composition in the mixture is 100:(5-20).

[0038] In this embodiment, the molar ratio of the biodegradable polyester to the coordination functional composition is set to 100:(5-20). This ratio provides sufficient coordination sites without excessively damaging the crystallinity and continuity of the polyester itself. The coordination functional composition itself contains multiple hydroxyl (-OH) or carboxyl (-COOH) groups. During melt blending, the coordination functional composition can be grafted onto the polyester molecular chain through transesterification or hydrogen bonding, introducing more coordination sites into the polyester molecular chain, thereby improving the coordination degree between the biodegradable polyester and metal ions and increasing the strength of the biodegradable polyester.

[0039] In some embodiments, the molar ratio of the degradable and coordinable polyester to the metal ion source is 100:(1-10).

[0040] In this embodiment, the molar ratio of degradable and coordinateable polyester to the metal ion source is set to 100:(1-10). The metal ions, acting as crosslinking centers, coordinate with coordination sites on the degradable and coordinateable polyester chains to form coordinate bonds. These coordinate bonds are dynamically reversible. Under no stress, the coordinate bonds are stable crosslinking points, providing strength to the polyester. Under external force, the coordinate bonds can break, dissipating energy and providing toughness to the polyester. After the external force disappears, the coordinate bonds can re-bond. In summary, at this molar ratio, the degradable polyester nonwoven fabric can improve both strength and toughness without compromising its intrinsic properties.

[0041] In some embodiments, the mass percentage of the metal ion source in the solution is 1%-10%.

[0042] In this embodiment, the mass percentage of the metal ion source in the solution is set between 1% and 10%. This metal ion acts as a second coordination site. Since the biodegradable polyester has already undergone the first coordination, it needs to be immersed in the solution containing the metal ion source for a second coordination. The metal ions diffuse from the bulk solution to the surface of the biodegradable polyester and then penetrate deeper to bind with the coordination sites. When the mass percentage of the metal ions is less than 1%, the diffusion kinetics are insufficient, resulting in a prolonged reaction time. When the mass percentage of the metal ions is greater than 10%, a dense layer forms on the surface of the biodegradable polyester, hindering the diffusion of metal ions into the interior and causing uneven cross-linking. Furthermore, the coordination of metal ions with the coordination sites on the biodegradable polyester is a reversible process. When the mass percentage of the metal ions is between 1% and 10%, the chemical equilibrium can be shifted towards the formation of coordination bonds, creating sufficient cross-linking points and controlling excessive cross-linking or metal ion aggregation and precipitation. In addition, metal ions can regulate the pH and viscosity of the solution. When the mass percentage of metal ions is between 1% and 10%, the metal ion solution has good fluidity and can regulate the pH of the coordination environment, promoting the coordination of metal ions.

[0043] In some embodiments, the melt blending temperature is 180°C-200°C.

[0044] In this embodiment, the melt blending temperature of the biodegradable polyester, the coordination functional composition, and the metal ion source is set to 180℃-200℃. This temperature range is higher than the melting point of the biodegradable polyester, ensuring that the biodegradable polyester, the coordination functional composition, and the metal ion source are in a molten state during blending. This improves the mobility of the biodegradable polyester molecular chains, allowing the coordination functional composition to disperse into the biodegradable polyester. At this temperature, the coordination interaction between the metal ions and the coordination sites in the biodegradable polyester molecules is more complete. Furthermore, the formation of coordination bonds requires sufficient energy. Setting the temperature within the 180℃-200℃ range enhances the electron-donating ability of the coordination functional composition, reducing the difficulty of forming coordination bonds with metal ions and shortening the coordination time. Furthermore, setting the temperature between 180℃ and 200℃ allows for control of the structure and stability of biodegradable polyester. At this temperature, the coordination number of metal ions increases, and the connection with coordination sites becomes tighter, enabling the formation of a stable three-dimensional cross-linked structure. Additionally, this temperature reduces the number of water molecules in the system, limiting the competition between water molecules and metal ions for coordination and increasing the number of coordination functional compositions bound to metal ions, thereby improving the strength and stability of biodegradable polyester nonwoven fabrics.

[0045] In some embodiments, when laying nascent fibers into a web, the forming process includes at least one of meltblowing, spunbonding, and hot rolling.

[0046] In this embodiment, nascent fibers are laid into a web using a meltblown process. The nascent fibers are melted and fed into a spinneret assembly. High-temperature, high-speed hot air is introduced on both sides of the spinneret orifice. As the melt is extruded from the orifice, it is drawn and stretched by this airflow, forming fibers. These fibers, under the influence of the high-speed airflow, randomly fly towards a receiving device and accumulate into a web. These fibers adhere to each other using their residual heat, forming a fiber web. The fibers formed by the meltblown process are extremely fine, porous, and dense, possessing excellent adsorption properties and a soft texture. Nascent fibers are then laid into a web using a spunbond process. Biodegradable polyester melt is filtered and metered, then extruded from the spinneret to form a fine stream. The extruded stream is then strongly stretched by a high-speed airflow or mechanical device, thinning it to form high-strength continuous filaments. After being drawn, the filaments are evenly laid on a forming curtain to form a fiber web. Finally, the fiber web is bonded and reinforced by hot rolling to form a biodegradable polyester nonwoven fabric. Spunbond technology uses continuous filaments that are fully stretched, resulting in biodegradable polyester nonwoven fabrics with high tensile and tear strength in both the longitudinal and transverse directions. The loose web structure with large pores provides excellent air permeability. A hot-rolling process lays up nascent fibers into a web. These fibers are added to heated steel rollers, where the softened or melted fibers flow under the pressure of the hot rollers and fuse with adjacent fibers at contact points. After the fibers leave the rollers and cool, these connections solidify, forming a complete biodegradable polyester nonwoven fabric. Hot-rolling provides rapid reinforcement, smooths the surface of the biodegradable polyester nonwoven fabric, and creates adhesion at the intersections of the nascent fibers, thereby improving the overall strength and stability of the fabric.

[0047] This application also provides a coordination-based biodegradable polyester nonwoven fabric, which is prepared by any of the preparation methods of coordination-based biodegradable polyester nonwoven fabric in the foregoing technical solutions. The coordination-based biodegradable polyester nonwoven fabric has all the beneficial effects of the preparation methods of coordination-based biodegradable polyester nonwoven fabric described above, and will not be elaborated further here.

[0048] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0049] I. Preparation Method Example 1 Polylactic acid, citric acid, and zinc acetate were added to a reactor in a molar ratio of 100:12:4 and melt-blended and granulated at 180-200℃ to obtain masterbatch. The masterbatch was fed into the feed port of a screw extruder and melt-spun at 210℃, followed by melt spinning (spinneret orifice diameter 0.3mm) to obtain nascent fibers. Using a spunbond process with an airflow drafting speed of 3000m / min, the nascent fibers were laid into a web and then hot-rolled (temperature 80℃) to obtain a fiber web. The fiber web was immersed in a 5% ZnCl2 aqueous solution and treated at 60℃ for 30min. After drying at 60℃, the biodegradable polyester nonwoven fabric based on coordination interaction of Example 1 was obtained.

[0050] Example 2-11 Examples 2-11 provide methods for preparing biodegradable polyester nonwoven fabrics based on coordination effects. Compared with Example 1, the only difference is the type of raw material, which is changed in at least one of the biodegradable polyester, coordination functional composition, and metal ion source. The remaining steps are the same as in Example 1 and will not be repeated here. The specific types of raw materials used in Examples 2-11 are shown in Table 1.

[0051] Table 1 lists the raw materials used in the preparation method of biodegradable polyester nonwoven fabric based on coordination. The PBST modified with imidazole-4,5-dicarboxylic acid was prepared by the following method: imidazole-4,5-dicarboxylic acid, terephthalic acid, bio-based diol, dimethyl succinate and isopropyl titanate were uniformly mixed in a molar ratio of 1:1.5:2:9:0.0015, and then esterified under a nitrogen atmosphere to obtain a prepolymer. After polycondensation, a polyester was obtained. The polyester was uniformly mixed with metal ions to form a metal coordination effect. After cooling, the PBST modified with imidazole-4,5-dicarboxylic acid was obtained.

[0052] Examples 11-14 Examples 11-14 provide methods for preparing biodegradable polyester nonwoven fabrics based on coordination effects. Compared with Example 1, the only difference is the change in the molar ratio of biodegradable polyester and coordination functional composition; the remaining steps are the same as in Example 1 and will not be repeated here. The specific molar ratios used in Examples 11-14 are shown in Table 2.

[0053] Table 2 shows the molar ratio of biodegradable and coordinable polyester to metal ions. Comparative Example 1 This comparative example provides a method for preparing a biodegradable polyester nonwoven fabric based on coordination. Compared with Example 1, the only difference is that the step of immersing the fiber web in a ZnCl2 aqueous solution is omitted. All other steps are the same as in Example 1 and will not be repeated here.

[0054] Comparative Example 2 This comparative example provides a method for preparing a biodegradable polyester nonwoven fabric based on coordination. Compared with Example 1, the only difference is that the step of adding citric acid is omitted. All other steps are the same as in Example 1 and will not be repeated here.

[0055] Comparative Example 3 This comparative example provides a polylactic acid (PLA) nonwoven fabric. PLA is melt-spun (spinneret orifice diameter 0.3 mm) to obtain nascent fibers. Using a spunbond process with an airflow drafting speed of 3000 m / min, the nascent fibers are laid into a web, hot-rolled (temperature 80℃), and then cooled to obtain the PLA nonwoven fabric of Comparative Example 3.

[0056] II. Testing Methods Tensile strength test method: The test shall be conducted in accordance with GB / T24218.3 / ISO9073-3; Test method for weight loss rate: The test shall be conducted in accordance with GB / T24218 / ISO9867.

[0057] III. Analysis of Test Results for Each Embodiment and Comparative Example Table 3 shows the test results of Examples 1-14 and Comparative Examples 1-3. Conclusion: By comparing Examples 1-14 and Comparative Examples 1-3, it was found that polyester undergoes initial coordination with metal ions. Polyester can coordinate with metal ions, and the coordination functional composition can modify biodegradable polyester. Through copolymerization, molecular chains with additional coordination groups (such as carboxyl or pyridyl groups) are embedded into the biodegradable polyester backbone, providing stronger coordination sites. Metal ions can simultaneously bind to coordination sites on two or more different biodegradable and coordinateable polyester chains. When metal ions approach atoms containing lone pairs of electrons on the biodegradable and coordinateable polyester, they coordinate with them and redistribute the electron cloud within the adsorbed molecule, thereby activating the molecule and making stable chemical bonds more reactive, facilitating subsequent reactions. When metal ions connect the molecular chains of the biodegradable and coordinateable polyester layer by layer, a physical cross-linked network is formed, increasing the strength of the biodegradable polyester. The biodegradable polyester fiber web undergoes a second coordination process. Utilizing the remaining coordination sites, new metal ions occupy the coordination vacancies, achieving secondary coordination. These new metal ions can further improve the performance of the biodegradable polyester. Alternatively, the metal ions can further coordinate with a second metal ion. When the two metal ions are very close, they can work synergistically in the molecular chain of the biodegradable polyester to form a double network structure, further improving the performance of the biodegradable polyester. The metal ions introduced through the two coordination processes will provide more properties to the biodegradable polyester, improving its tensile strength and stability.

[0058] In summary, the synergistic effect of secondary coordination improves the strength and stability of biodegradable polyesters, thereby enhancing their performance. By selecting different secondary coordinated metal ions and utilizing their intrinsic properties, different properties can be provided to biodegradable polyesters.

[0059] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing a biodegradable polyester nonwoven fabric based on coordination interaction, characterized in that, include: Provides biodegradable and coordinateable polyesters; The degradable and coordinateable polyester includes a mixture of degradable polyester and a coordination functional composition or a coordination-modified degradable polyester. The biodegradable and coordinateable polyester and metal ion source are melt-blended and granulated to obtain masterbatch; The masterbatch is melt-spun to obtain nascent fibers; The nascent fibers are laid into a web to obtain a fiber web; The fiber web is impregnated in a solution containing a metal ion source for recoordination, and then post-treated to obtain a biodegradable polyester nonwoven fabric based on coordination.

2. The method for preparing biodegradable polyester nonwoven fabric based on coordination interaction according to claim 1, characterized in that, The biodegradable polyester includes at least one of polylactic acid, polycaprolactone, polyhydroxyalkanoate, and polybutylene succinate; the coordination-modified biodegradable polyester includes PBST polyester modified with imidazole-4,5-dicarboxylic acid.

3. The method for preparing biodegradable polyester nonwoven fabric based on coordination interaction according to claim 1, characterized in that, The coordination functional composition includes at least one of citric acid, dopamine, chitosan, and 8-hydroxyquinoline.

4. The method for preparing biodegradable polyester nonwoven fabric based on coordination interaction according to claim 1, characterized in that, The metal ions in the metal ion source include at least one of zinc, copper, silver, iron, and calcium.

5. The method for preparing biodegradable polyester nonwoven fabric based on coordination interaction according to claim 1, characterized in that, In the mixture of the biodegradable polyester and the coordination functional composition, the molar ratio of the biodegradable polyester to the coordination functional composition is 100:(5-20).

6. The method for preparing biodegradable polyester nonwoven fabric based on coordination interaction according to claim 1, characterized in that, The molar ratio of the degradable and coordinateable polyester to the metal ion source is 100:(1-10).

7. The method for preparing biodegradable polyester nonwoven fabric based on coordination interaction according to claim 1, characterized in that, In the solution containing the metal ion source, the mass percentage of the metal ion source is 1%-10%.

8. The method for preparing biodegradable polyester nonwoven fabric based on coordination interaction according to claim 1, characterized in that, The melt blending temperature is 180℃-200℃.

9. The method for preparing biodegradable polyester nonwoven fabric based on coordination interaction according to claim 1, characterized in that, When the nascent fibers are laid into a web, the forming process includes at least one of meltblown, spunbond, and hot rolling.

10. A biodegradable polyester nonwoven fabric based on coordination, characterized in that, It is prepared by the method for preparing the biodegradable polyester nonwoven fabric based on coordination as described in any one of claims 1-9.

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