A silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material and a method for preparing the same

Abstract

The application discloses a kind of silane modified polyglycolic acid fiber reinforced polybutylene succinate biodegradable composite material and preparation method thereof, belong to high molecular biodegradable composite material technical field, the surface modification of polyglycolic acid fiber is carried out in the present application, and chain extender is introduced under the condition of lower processing temperature synergistic effect, overcome the technical prejudice that polyglycolic acid fiber is difficult to effectively enhance the performance in polybutylene succinate system, realizes the improvement of polybutylene succinate tensile strength under the premise of not significantly reducing material toughness.

Description

Technical Field

[0001] This invention belongs to the field of polymer biodegradable composite materials technology, and particularly relates to a silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material and its preparation method. Background Technology

[0002] With the increasing demand for biodegradable polymer materials in packaging, agriculture, and biomedicine, polybutylene succinate (PBS) has attracted widespread attention due to its good flexibility and processing properties. However, the low tensile strength and modulus of PBS limit its application in situations requiring high mechanical properties.

[0003] To improve the mechanical properties of PBS, existing technologies typically employ reinforcement by introducing high-rigidity components. Polyglycolic acid (PGA) is considered a potential reinforcing material due to its high strength and modulus. Current research mainly focuses on PBS / PGA particle or blend systems, preparing PBS / PGA materials through melt blending to improve material rigidity.

[0004] However, it is generally believed in the art that polyglycolic acid (PGA) materials have poor thermal stability during melt processing, especially their fiber morphology, which is prone to breakage or degradation under shear and thermal history (PGA materials degrade at around 200°C during actual processing, specifically referring to the breakage of PGA segments and a decrease in molecular weight; PGA fibers are obtained by melt spinning and stretching PGA particles; the higher the spinning temperature (e.g., 250°C), the easier it is to induce degradation. That is, PGA fibers are more prone to fiber breakage and degradation than PGA particles during blending due to the combined effects of screw shearing and the thermal history of the spinning process); at the same time, fiber-reinforced polymer systems usually require higher processing temperatures to achieve sufficient wetting of the fibers by the matrix and effective stress transfer (for most polymers, the addition of fibers leads to a significant increase in melt viscosity; in order to obtain sufficient fluidity so that the melt can fully impregnate the fibers, the temperature is usually increased to reduce viscosity). For polyglycolic acid (PGA) fibers, the melting point of PGA is between 220-230℃, and the thermal decomposition temperature is 240℃ (under nitrogen). In actual processing, the thermal decomposition temperature will be even lower, so increasing the temperature is not suitable for PGA fibers. Therefore, existing technologies generally do not favor using PGA in fiber form in PBS melt fiber reinforced composite systems, and it is even more difficult to achieve stable reinforcement under lower processing temperature conditions.

[0005] Furthermore, during PBS processing, thermal degradation and molecular weight reduction in the molten state limit the stability of the reinforcement effect. Although chain extenders can be used to improve polymer molecular weight, their synergistic effect with the fiber reinforcement system has not been fully studied. Therefore, how to achieve effective reinforcement of PBS by PGA fibers at lower processing temperatures, while taking into account the processing stability and mechanical properties of the material, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a silane-modified polyglycolic acid fiber-reinforced polybutylene succinate (PBS) biodegradable composite material and its preparation method. This invention overcomes the technical bias that polyglycolic acid fibers are difficult to effectively enhance the performance of PBS in the PBS system by surface modification of polyglycolic acid fibers and the introduction of chain extenders at lower processing temperatures. This achieves an increase in the tensile strength of PBS without significantly reducing the material's toughness.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material (silane-modified PGA fiber-reinforced PBS biodegradable composite material), comprising the following raw materials: polybutylene succinate (PBS), modified polyglycolic acid (PGA) fiber, chain extender and antioxidant; The modified PGA fiber is a silane-modified PGA fiber.

[0008] Furthermore, the modified PGA fiber accounts for 10-20% of the total mass of the PBS and the modified PGA fiber; This invention uses polybutylene succinate (PBS) as the matrix and chopped polyglycolic acid (PGA) fibers modified with a silane coupling agent as the reinforcing phase to prepare a silane-modified PGA fiber-reinforced PBS biodegradable composite material. This achieves an improvement in the tensile strength of PBS without significantly reducing the material's toughness. The improved mechanical properties achieved by this composite material are not due to the simple superposition of single technical features, but rather the result of a synergistic effect between the selection of reinforcing phase morphology, interfacial chemical regulation, and molecular weight stabilization mechanisms. This synergistic effect enables the composite material to achieve effective stress transfer and structural stability even at relatively low processing temperatures.

[0009] The amount of chain extender added is 0-1% of the total mass of the PBS and modified PGA fibers, and the amount of chain extender added is not 0. The amount of antioxidant added is 0-1% of the total mass of the PBS and modified PGA fibers, and the amount of antioxidant added is not 0.

[0010] Furthermore, the preparation method of the silane-modified PGA fiber is as follows: cut the PGA fiber into 1-3 mm lengths to obtain short-cut PGA fibers; The PGA short-cut fibers were added to a silane coupling agent hydrolysis solution, magnetically stirred, and dried to obtain the silane-modified polyglycolic acid fibers.

[0011] Furthermore, the preparation method of the silane coupling agent hydrolysis solution is as follows: under magnetic stirring, the silane coupling agent is added to a mixed solvent of ethanol and water, and its final concentration is controlled to be 1.0 wt%. The mixture is stirred evenly to obtain the silane coupling agent hydrolysis solution.

[0012] Furthermore, the method for preparing the silane coupling agent hydrolysis solution is as follows: a mixed solvent of ethanol and deionized water is prepared at a volume ratio of 4:1; then, under magnetic stirring, the silane coupling agent is added to the above mixed solvent, and the amount added is controlled to a final concentration of 1.0 wt%. The mixture is stirred continuously at room temperature for 30 minutes to obtain the silane coupling agent hydrolysis solution.

[0013] Furthermore, the silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane (KH550), γ-glycidoxypropyltrimethoxysilane (KH560), γ-methacryloyloxypropylsilane (KH570), and γ-mercaptopropyltriethoxysilane (KH580).

[0014] Furthermore, the mass ratio of the PGA chopped fibers to the silane coupling agent hydrolysis solution is 1:(5-15); The magnetic stirring process takes 6-12 hours.

[0015] Furthermore, the antioxidant is selected from one of antioxidant 2112, antioxidant 1076 and antioxidant 1010.

[0016] Furthermore, the chain extender is an epoxy chain extender.

[0017] The present invention also provides a method for preparing the above-mentioned silane-modified PGA fiber reinforced PBS biodegradable composite material, comprising the following steps: melt blending PBS, modified PGA fiber, chain extender and antioxidant to obtain the silane-modified PGA fiber reinforced PBS biodegradable composite material; The temperature of the melt blending is not higher than 180°C.

[0018] Furthermore, the melt blending temperature is 150°C.

[0019] This invention uses polybutylene succinate (PBS) as the matrix and chopped polyglycolic acid (PGA) fibers modified with silane coupling agent as the reinforcing phase to prepare a silane-modified PGA fiber reinforced PBS biodegradable composite material by blending at a relatively low melting temperature. This improves the tensile strength of PBS without significantly reducing the toughness of the material.

[0020] Furthermore, the melt blending time is 3-8 minutes.

[0021] Furthermore, during the melt blending process, the screw speed is 50 rpm.

[0022] Compared with the prior art, the present invention has the following advantages and technical effects: 1. Significant improvement in the mechanical properties of composite materials can still be achieved under low-temperature melting conditions; 2. By leveraging the synergistic effects of fiber morphology, interface modification, and chain extenders, the optimal performance window for nonlinear reinforcement of composite materials is achieved; 3. The processing temperature is lowered, reducing the risk of thermal degradation and making it suitable for industrial applications. Detailed Implementation

[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0024] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0025] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0026] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0027] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0028] An embodiment of the present invention provides a silane-modified PGA fiber-reinforced PBS biodegradable composite material, comprising the following raw materials: polybutylene succinate (PBS), modified polyglycolic acid (PGA) fiber, chain extender and antioxidant; The modified PGA fiber is a silane-modified PGA fiber.

[0029] In a preferred embodiment of the present invention, the modified PGA fiber accounts for 10-20% of the total mass of PBS and the modified PGA fiber, and preferably 10-15% of the total mass of PBS and the modified PGA fiber. The amount of chain extender added is 0-1% of the total mass of PBS and modified PGA fibers. The amount of chain extender added is not zero, and preferably it is 0.5% of the total mass of PBS and modified PGA fibers. The amount of antioxidant added is 0-1% of the total mass of PBS and modified PGA fiber. The amount of antioxidant added is not zero, and preferably it is 0.5% of the total mass of PBS and modified PGA fiber.

[0030] In a preferred embodiment of the present invention, the method for preparing silane-modified PGA fibers is as follows: PGA fibers are cut into 1-3 mm lengths to obtain short-cut PGA fibers; PGA short-cut fibers were added to a silane coupling agent hydrolysis solution, magnetically stirred, and dried to obtain silane-modified polyglycolic acid fibers.

[0031] In a preferred embodiment of the present invention, the method for preparing the silane coupling agent hydrolysis solution is as follows: a mixed solvent of ethanol and deionized water is prepared at a volume ratio of 4:1; then, under magnetic stirring, the silane coupling agent is added to the above mixed solvent, and the amount added is controlled to a final concentration of 1.0 wt%. The mixture is stirred continuously at room temperature for 30 minutes to obtain the silane coupling agent hydrolysis solution.

[0032] In a preferred embodiment of the present invention, the silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane (KH550), γ-glycidoxypropyltrimethoxysilane (KH560), γ-methacryloyloxypropylsilane (KH570), and γ-mercaptopropyltriethoxysilane (KH580).

[0033] In a preferred embodiment of the present invention, the mass ratio of PGA chopped fibers to silane coupling agent hydrolysis solution is 1:(5-15), preferably 1:10; The magnetic stirring treatment time is 6-12 hours, preferably 9 hours, which allows the silane coupling agent to fully modify the PGA short-cut fibers.

[0034] In a preferred embodiment of the present invention, the modified PGA fiber is dried at a temperature of 80°C for 12 hours.

[0035] In a preferred embodiment of the present invention, the antioxidant is selected from one of antioxidant 2112, antioxidant 1076 and antioxidant 1010.

[0036] In a preferred embodiment of the present invention, the chain extender is an epoxy chain extender.

[0037] For example, the epoxy chain extender is selected from one of ADR 4468, HPC-3510P, ECO-1120, SG-20 and FB-120.

[0038] The embodiments of the present invention also provide a method for preparing the above-mentioned silane-modified PGA fiber reinforced PBS biodegradable composite material, comprising the following steps: melt blending PBS, modified PGA fiber, chain extender and antioxidant to obtain silane-modified PGA fiber reinforced PBS biodegradable composite material; The temperature for melt blending should not exceed 180℃.

[0039] In a preferred embodiment of the present invention, the melt blending temperature is 150°C.

[0040] In a preferred embodiment of the present invention, the melt blending time is 3-8 minutes.

[0041] In a preferred embodiment of the present invention, the screw speed is 50 rpm during melt blending.

[0042] This invention uses polyglycolic acid fiber to reinforce PBS at low temperatures. Since the melting point of PBS is below 120°C, blending at low temperatures (such as 150°C) can ensure sufficient melt flowability and avoid problems such as degradation and molecular weight reduction of polyglycolic acid fiber caused by high temperatures.

[0043] Unless otherwise specified, the room temperature in this invention is 25±2℃.

[0044] All raw materials used in the embodiments and comparative examples of this invention were purchased commercially. As an example, polybutylene succinate (PBS), model XK-202407180016, was purchased from Xuke New Materials (Shandong) Co., Ltd.; polyglycolic acid (PGA) particles were purchased from Madigre (Shanghai) Materials Technology Co., Ltd., with a particle size of 8-10 mesh; polyglycolic acid (PGA) fibers were purchased from Madigre (Shanghai) Materials Technology Co., Ltd., consisting of 8000m long fibers made from 500g of PGA particles, with a linear density of 625 dtex. The chain extender ADR 4468 was purchased from BASF (Germany).

[0045] In the embodiments of the present invention, the instruments and equipment used mainly include: Miniature conical twin-screw extruder: DHE-15 / 40 type, Shanghai Changkai Electromechanical Technology Co., Ltd.; Miniature injection molding machine: DHI-15 model, Shanghai Changkai Electromechanical Technology Co., Ltd.; Heat distortion and Vicat softening point temperature measuring instrument: XRW-300A-3, Chengde Jiaze Testing Equipment Co., Ltd.; Tensile testing machine: XBD4000GD model, Shanghai Xinbiao Testing Instruments Manufacturing Co., Ltd.

[0046] In the following embodiments and comparative examples of the present invention, the test standards are as follows: 1. Test standard for longitudinal tensile properties (tensile strength): GB / T 10004-2008; 2. Test standard for heat distortion temperature: GB / T 1633-2000.

[0047] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0048] The technical solution of the present invention will be further illustrated by the following embodiments.

[0049] Example 1 A method for preparing a silane-modified PGA fiber-reinforced biodegradable PBS composite material, comprising the following steps: 1. Preparation of modified PGA chopped fibers PGA fibers were cut into 1-3 mm lengths to obtain chopped PGA fibers, which were then collected. A silane coupling agent hydrolysis solution was prepared as follows: a mixed solvent of ethanol and deionized water was prepared at a volume ratio of 80:20; then, KH550 was added to the mixed solvent under magnetic stirring, controlling the addition amount to a final concentration of 1.0 wt%, and stirred continuously at room temperature for 30 minutes to obtain the silane coupling agent hydrolysis solution. The chopped PGA fibers were added to the silane coupling agent hydrolysis solution (the mass ratio of chopped PGA fibers to the silane coupling agent hydrolysis solution was 1:10), magnetically stirred for 9 hours, and dried at 80°C for 12 hours to obtain modified PGA chopped fibers.

[0050] 2. Preparation of silane-modified PGA fiber-reinforced biodegradable PBS composite material 100 parts by weight of PBS / modified PGA chopped fiber blend resin (PBS accounting for 90 wt% and modified PGA chopped fiber accounting for 10 wt%) were mixed with 0.5% chain extender (ADR 4468) and 0.5% antioxidant (lrganox 1010), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150℃ and the screw speed was 50 rpm. After circulating blending for 5 minutes, the mixture was melt-extruded and granulated to obtain a silane-modified PGA fiber reinforced PBS biodegradable composite material.

[0051] Testing of silane-modified PGA fiber-reinforced PBS biodegradable composite material: The silane-modified PGA fiber-reinforced PBS biodegradable composite material was placed in a micro injection molding machine. The temperature of zone one of the micro injection molding machine was set to 150℃ (i.e., the temperature of the material hopper of the micro injection molding machine was 150℃), the temperature of zone two of the mold (i.e., the temperature of zone two of the micro injection molding machine) was set to 40℃, the injection time was 5s, and the holding time was 15s. The sample was injection molded to meet the standard, and relevant tests were carried out according to the test standards (test standard for longitudinal tensile properties: GB / T 10004-2008; test standard for heat distortion temperature: GB / T 1633-2000). The physical properties of the composite material are shown in Table 1.

[0052] Example 2 A method for preparing a silane-modified PGA fiber-reinforced biodegradable PBS composite material, comprising the following steps: 1. Preparation of modified PGA chopped fibers Same as Example 1.

[0053] 2. Preparation of silane-modified PGA fiber-reinforced biodegradable PBS composite material 100 parts by weight of PBS / modified PGA fiber blend resin (PBS accounting for 85 wt% and modified PGA chopped fiber accounting for 15 wt%) were mixed with 0.5% chain extender (same as in Example 1) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150°C and the screw speed was 50 rpm. After circulating blending for 5 min, the mixture was melt-extruded and granulated to obtain a silane-modified PGA fiber reinforced PBS biodegradable composite material.

[0054] The injection molding process and performance testing of the silane-modified PGA fiber-reinforced PBS biodegradable composite material are the same as in Example 1. The physical properties of the composite material are shown in Table 1.

[0055] Example 3 A method for preparing a silane-modified PGA fiber-reinforced biodegradable PBS composite material, comprising the following steps: 1. Preparation of modified PGA chopped fibers Same as Example 1.

[0056] 2. Preparation of silane-modified PGA fiber-reinforced biodegradable PBS composite material 100 parts by weight of PBS / modified PGA chopped fiber blend resin (PBS accounting for 80 wt% and modified PGA chopped fiber accounting for 20 wt%) were mixed with 0.5% chain extender (same as in Example 1) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150°C and the screw speed was 50 rpm. After circulating blending for 5 min, the mixture was melt-extruded and granulated to obtain a silane-modified PGA fiber reinforced PBS biodegradable composite material.

[0057] The injection molding process and performance testing of the silane-modified PGA fiber-reinforced PBS biodegradable composite material are the same as in Example 1. The physical properties of the composite material are shown in Table 1.

[0058] Comparative Example 1 A method for preparing a silane-modified PGA fiber-reinforced biodegradable PBS composite material, comprising the following steps: 1. Preparation of modified PGA chopped fibers Same as Example 1.

[0059] 2. Preparation of silane-modified PGA fiber-reinforced biodegradable PBS composite material 100 parts by weight of PBS / modified PGA chopped fiber blend resin (PBS accounting for 95 wt% and modified PGA chopped fiber accounting for 5 wt%) were mixed with 0.5% (i.e., the amount of chain extender added was 0.5% of the total mass of PBS and modified PGA fiber) of chain extender (same as in Example 1) and 0.5% (i.e., the amount of antioxidant added was 0.5% of the total mass of PBS and modified PGA fiber) of antioxidant (same as in Example 1). The mixture was then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150°C and the screw speed was 50 rpm. After cyclic blending for 5 minutes, the mixture was melt-extruded and granulated to obtain a silane-modified PGA fiber reinforced PBS biodegradable composite material, which can also be called PBS / modified PGA chopped fiber composite material.

[0060] The injection molding process and performance testing of the silane-modified PGA fiber-reinforced PBS biodegradable composite material are the same as in Example 1. The physical properties of the composite material are shown in Table 1.

[0061] Table 1. Physical properties of the composite materials prepared in Comparative Example 1 and Examples 1-3

[0062] As shown in Table 1, the addition of PGA fibers significantly improves the tensile strength of the PBS matrix. This is mainly attributed to the high strength and high modulus of the PGA fibers themselves, enabling them to effectively bear and transfer stress. With the increase of PGA fiber content in the PBS matrix, the tensile strength of the composite material shows a trend of first increasing and then decreasing. At lower fiber contents, the tensile strength gradually increases with increasing fiber content; when the PGA fiber content is approximately 15% (mass percentage, the same below), the tensile strength reaches its peak. However, when the fiber content increases to 20%, the tensile strength decreases. This is mainly because excessively high fiber content easily leads to uneven dispersion of fibers in the matrix, causing fiber agglomeration and weakening interfacial bonding; simultaneously, high fiber content easily induces stress concentration within the composite material and forms defects during fiber debonding, thus deteriorating the overall mechanical properties of the material.

[0063] When the PGA fiber content is 5%, the content is relatively low, dispersion is relatively easy, agglomeration is not significant, and the performance is slightly improved. When the content increases to 10%-15%, the heat distortion temperature reaches the critical point of high content. When the content reaches 20%, PGA fibers agglomerate, and the heat distortion temperature decreases to 99.35℃.

[0064] The degradation performance of the composite materials prepared in Comparative Example 1 and Examples 1-3 was tested. The degradation performance of the materials was characterized by a mass loss experiment. The specific method is as follows: The four composite materials were injection molded into small balls with a diameter of 17.60 mm at their respective melt blending processing temperatures. 40 mL of deionized water was added, and a mass loss experiment was carried out in a water bath at 90 °C for 144 h. The results are shown in Table 2.

[0065] Table 2. Degradation properties of the composite materials prepared in Comparative Example 1 and Examples 1-3

[0066] As shown in Table 2, the mass loss rate increases with the increase of PGA fiber content. This is mainly because the dispersed PGA fibers hydrolyze into acidic substances first, which promotes the hydrolysis of PBS.

[0067] Example 4 A method for preparing a silane-modified PGA fiber-reinforced biodegradable PBS composite material, comprising the following steps: 1. Preparation of modified PGA chopped fibers PGA fibers were cut into 1-3 mm lengths to obtain chopped PGA fibers, which were then collected. A silane coupling agent hydrolysis solution was prepared as follows: First, a mixed solvent of ethanol and deionized water was prepared at a volume ratio of 80:20. Then, under magnetic stirring, γ-methacryloyloxypropylsilane (KH570) was slowly added to the mixed solvent, controlling the addition amount to a final concentration of 1.0% (mass-volume ratio). The mixture was stirred continuously at room temperature for 30 minutes to obtain the desired treatment solution. The chopped PGA fibers were then added to the silane coupling agent hydrolysis solution (the mass ratio of chopped PGA fibers to the silane coupling agent hydrolysis solution was 1:5), magnetically stirred for 6 hours, and dried at 80°C for 12 hours to obtain modified chopped PGA fibers.

[0068] 2. Preparation of silane-modified PGA fiber-reinforced biodegradable PBS composite material 100 parts by weight of PBS / modified PGA chopped fiber blend resin (PBS accounting for 85 wt% and modified PGA chopped fiber accounting for 15 wt%) were mixed with 0.1% chain extender (ECO-1120) and 0.1% antioxidant (antioxidant 1010), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150℃ and the screw speed was 50 rpm. After circulating blending for 3 minutes, the mixture was melt-extruded and granulated to obtain a silane-modified PGA fiber reinforced PBS biodegradable composite material.

[0069] The injection molding process and performance testing of the silane-modified PGA fiber-reinforced PBS biodegradable composite material are the same as in Example 1.

[0070] The silane-modified PGA fiber-reinforced PBS biodegradable composite material prepared in this embodiment has a heat distortion temperature of 97.87℃ and a tensile strength of 62.14MPa.

[0071] Example 5 A method for preparing a silane-modified PGA fiber-reinforced biodegradable PBS composite material, comprising the following steps: 1. Preparation of modified PGA chopped fibers PGA fibers were cut into 1-3 mm lengths to obtain chopped PGA fibers, which were then collected. A silane coupling agent hydrolysis solution was prepared as follows: First, a mixed solvent of ethanol and deionized water was prepared at a volume ratio of 80:20. Then, under magnetic stirring, γ-aminopropyltriethoxysilane (KH550) and γ-glycidoxypropyltrimethoxysilane (KH560) were mixed at a mass ratio of 1:1, and then slowly added to the mixed solvent, controlling the addition amount to a final concentration of 1.0% (mass-volume ratio). The mixture was stirred continuously at room temperature for 30 minutes to obtain the desired treatment solution. The chopped PGA fibers were then added to the silane coupling agent hydrolysis solution (the mass ratio of chopped PGA fibers to the silane coupling agent hydrolysis solution was 1:10), magnetically stirred for 10 hours, and dried at 80°C for 12 hours to obtain modified chopped PGA fibers.

[0072] 2. Preparation of silane-modified PGA fiber-reinforced biodegradable PBS composite material 100 parts by weight of PBS / modified PGA chopped fiber blend resin (PBS accounting for 85 wt% and modified PGA chopped fiber accounting for 15 wt%) were mixed with 1% chain extender (ADR 4468) and 1% antioxidant (antioxidant 2112), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150℃ and the screw speed was 50 rpm. After circulating blending for 8 minutes, the mixture was melt-extruded and granulated to obtain silane-modified PGA fiber reinforced PBS biodegradable composite material.

[0073] The injection molding process and performance testing of the silane-modified PGA fiber-reinforced PBS biodegradable composite material are the same as in Example 1.

[0074] The silane-modified PGA fiber-reinforced PBS biodegradable composite material prepared in this embodiment has a heat distortion temperature of 97.82℃ and a tensile strength of 64.35MPa.

[0075] Example 6 A method for preparing a silane-modified PGA fiber-reinforced biodegradable PBS composite material, comprising the following steps: 1. Preparation of modified PGA chopped fibers PGA fibers were cut into 1-3 mm lengths to obtain chopped PGA fibers, which were then collected. A silane coupling agent hydrolysis solution was prepared as follows: First, a mixed solvent of ethanol and deionized water was prepared at a volume ratio of 80:20. Then, under magnetic stirring, γ-mercaptopropyltriethoxysilane (KH580) was slowly added to the mixed solvent, controlling the addition amount to a final concentration of 1.0% (mass-volume ratio). The mixture was stirred continuously at room temperature for 30 minutes to obtain the desired treatment solution. The chopped PGA fibers were then added to the silane coupling agent hydrolysis solution (the mass ratio of chopped PGA fibers to the silane coupling agent hydrolysis solution was 1:15), magnetically stirred for 12 hours, and dried at 80°C for 12 hours to obtain modified chopped PGA fibers.

[0076] 2. Preparation of silane-modified PGA fiber-reinforced biodegradable PBS composite material 100 parts by weight of PBS / modified PGA chopped fiber blend resin (PBS accounting for 90 wt% and modified PGA chopped fiber accounting for 10 wt%) were mixed with 0.5% chain extender (HPC-3510P) and 0.5% antioxidant (antioxidant 1076), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150℃ and the screw speed was 50 rpm. After cyclic blending for 6 minutes, the mixture was melt-extruded and granulated to obtain a silane-modified PGA fiber reinforced PBS biodegradable composite material.

[0077] The injection molding process and performance testing of the silane-modified PGA fiber-reinforced PBS biodegradable composite material are the same as in Example 1.

[0078] The silane-modified PGA fiber-reinforced PBS biodegradable composite material prepared in this embodiment has a heat distortion temperature of 91.15℃ and a tensile strength of 42.49 MPa.

[0079] Example 7 A method for preparing a silane-modified PGA fiber-reinforced PBS biodegradable composite material is the same as in Example 1, except that the temperature of each zone of the micro conical twin-screw extruder is set to 160°C.

[0080] The injection molding process and performance testing of the silane-modified PGA fiber-reinforced PBS biodegradable composite material were the same as in Example 1, except that the temperature of Zone 1 of the micro injection molding machine was set to 160°C.

[0081] The silane-modified PGA fiber-reinforced PBS biodegradable composite material prepared in this embodiment has a heat distortion temperature of 103.27℃ and a tensile strength of 69.25MPa.

[0082] Example 8 A method for preparing a silane-modified PGA fiber-reinforced PBS biodegradable composite material is the same as in Example 1, except that the temperature of each zone of the micro conical twin-screw extruder is set to 170°C.

[0083] The injection molding process and performance testing of the silane-modified PGA fiber-reinforced PBS biodegradable composite material were the same as in Example 1, except that the temperature of Zone 1 of the micro injection molding machine was set to 170°C.

[0084] The silane-modified PGA fiber-reinforced PBS biodegradable composite material prepared in this embodiment has a heat distortion temperature of 101.35℃ and a tensile strength of 67.42 MPa.

[0085] Comparative Example 2 1. Preparation of unmodified PGA chopped fibers: PGA fibers are cut into 1-3mm lengths to obtain short-cut PGA fibers without the use of silane coupling agents for modification.

[0086] 2. Preparation of PBS / unmodified PGA chopped fiber composite material 100 parts by weight of PBS / unmodified PGA chopped fiber blend resin (PBS accounting for 90 wt% and unmodified PGA chopped fiber accounting for 10 wt%) were mixed with 0.5% chain extender (same as in Example 1) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150°C and the screw speed was 50 rpm. After circulating blending for 5 minutes, the mixture was melt-extruded and granulated to obtain the PBS / unmodified PGA chopped fiber composite material.

[0087] The injection molding process and performance testing of the PBS / unmodified PGA chopped fiber composite material were the same as in Example 1. The physical properties of the composite material are shown in Table 3.

[0088] Comparative Example 3 Preparation of PBS / PGA particle composite material Before blending, PBS and PGA particles were dried in a vacuum oven at 80°C for 12 hours. 100 parts by weight of the PBS / PGA particle blend resin (PBS 95 wt%, PGA particles 5 wt%) was mixed with 0.5% chain extender (same as in Example 1) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 235°C, and the screw speed was 50 rpm. After cyclic blending for 5 minutes, the mixture was melt-extruded and granulated to obtain the PBS / PGA particle composite material.

[0089] Testing of PBS / PGA particle composite material: The PBS / PGA particle composite material was placed in a micro injection molding machine. The temperature of the micro injection molding machine was set to 235℃ (i.e., the temperature of the material hopper in zone 1 of the micro injection molding machine was 235℃), the mold zone temperature was set to 40℃, the injection time was 5s, and the holding pressure time was 15s. The composite material was injection molded into a standard specimen. The testing standards were the same as those in Example 1. The physical properties of the composite material are shown in Table 3.

[0090] Comparative Example 4 Preparation of PBS / PGA particle composite material Before blending, PBS and PGA particles were dried in a vacuum oven at 80°C for 12 hours. 100 parts by weight of the PBS / PGA particle blend resin (90 wt% PBS and 10 wt% PGA particles) were mixed with 0.5% chain extender (same as in Example 1) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 235°C, and the screw speed was 50 rpm. After cyclic blending for 5 minutes, the mixture was melt-extruded and granulated to obtain the PBS / PGA particle composite material.

[0091] The injection molding process and performance testing of the PBS / PGA particle composite material were the same as those in Comparative Example 3. The physical properties of the composite material are shown in Table 3.

[0092] Comparative Example 5 Preparation of PBS / PGA particle composite material Before blending, PBS and PGA particles were dried in a vacuum oven at 80°C for 12 hours. 100 parts by weight of the PBS / PGA particle blend resin (PBS accounting for 85 wt% and PGA particles accounting for 15 wt%) was mixed with 0.5% chain extender (same as in Example 1) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 235°C, and the screw speed was 50 rpm. After cyclic blending for 5 minutes, the mixture was melt-extruded and granulated to obtain the composite material masterbatch.

[0093] The injection molding process and performance testing of the PBS / PGA particle composite material were the same as those in Comparative Example 3. The physical properties of the composite material are shown in Table 3.

[0094] Comparative Example 6 Preparation of PBS / PGA particle composite material Before blending, PBS and PGA particles were dried in a vacuum oven at 80°C for 12 hours. 100 parts by weight of the PBS / PGA particle blend resin (80 wt% PBS and 20 wt% PGA particles) were mixed with 0.5% chain extender (same as in Example 1) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 235°C, and the screw speed was 50 rpm. After cyclic blending for 5 minutes, the mixture was melt-extruded and granulated to obtain the composite material masterbatch.

[0095] The injection molding process and performance testing of the PBS / PGA particle composite material were the same as those in Comparative Example 3. The physical properties of the composite material are shown in Table 3.

[0096] Comparative Example 7 Preparation of pure PBS materials Before blending, the PBS particles were dried in a vacuum oven at 80°C for 12 hours. 100 parts by weight of PBS particles were mixed with 0.5% chain extender (same as in Example 1) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150°C and the screw speed was 50 rpm. After cyclic blending for 5 minutes, the mixture was melt-extruded and granulated to obtain pure PBS.

[0097] Testing of pure PBS material: The temperature of zone one of the micro injection molding machine was set to 150℃, and the temperature of zone two was set to 40℃. The injection time was 5s, and the holding time was 15s. Standard specimens were injection molded, and the testing standards were consistent with those of Example 1. The measured physical properties of this material are shown in Table 3.

[0098] Comparative Example 8 A method for preparing a silane-modified PGA particle-reinforced biodegradable PBS composite material, comprising the following steps: 1. Preparation of modified PGA particles The preparation method of the silane coupling agent hydrolysis solution is the same as in Example 1. PGA particles were added to the silane coupling agent hydrolysis solution (the mass ratio of PGA particles to silane coupling agent hydrolysis solution was 1:10), magnetically stirred for 9 hours, and dried at 80°C for 12 hours to obtain modified PGA particles.

[0099] 2. Preparation of silane-modified PGA particle-reinforced biodegradable PBS composite material 100 parts by weight of PBS / modified PGA particle blend resin (PBS accounting for 90 wt% and modified PGA particles accounting for 10 wt%) were mixed with 0.5% chain extender (ADR 4468) and 0.5% antioxidant (same as in Example 1), and then added to a micro conical twin-screw extruder. The temperature of each zone of the micro conical twin-screw extruder was set to 150°C and the screw speed was 50 rpm. After cyclic blending for 5 minutes, the mixture was melt-extruded and granulated to obtain a silane-modified PGA particle-reinforced PBS biodegradable composite material. The injection molding process and performance testing methods were the same as in Example 1.

[0100] The comparative example of silane-modified PGA particle-reinforced PBS biodegradable composite material has a heat distortion temperature of 91.93℃ and a tensile strength of 42.56MPa.

[0101] Table 3. Physical properties of materials prepared in Comparative Examples 2-7

[0102] As shown in Table 3, a comparison between Comparative Example 2 and Example 1 of the present invention shows that the composite material obtained by blending modified PGA short chopped fibers has much better comprehensive mechanical properties than the composite material prepared by unmodified PGA short chopped fibers.

[0103] Compared to Comparative Examples 3-6 (particle-reinforced systems), Examples 2-3 (fiber-reinforced systems) showed a more significant increase in tensile strength, indicating that the reinforcing effect of PGA fibers is superior to that of PGA particles. The high aspect ratio of PGA fibers allows them to form a continuous or semi-continuous reinforcing network, which plays a major role under stress or heat, rather than merely assisting the matrix. With increasing PGA fiber content, the tensile strength of the composite material rises rapidly; at the same addition amount, the increase in tensile strength of the fiber-reinforced system is generally higher than that of the particle system. This is mainly due to the continuous reinforcing characteristics of PGA fibers and their more efficient stress transfer mechanism with the matrix: during tensile testing, the high-modulus PGA fibers act as the main load-bearing phase, bearing most of the load, while the PBS matrix plays a role in stress transfer and fiber protection. The constraint effect of PGA fibers on matrix deformation gives the composite material a higher macroscopic stiffness. The reinforcing efficiency of PGA fibers is higher than that of PGA particles. To achieve the same strength, it may be necessary to add particles in much greater quantities than PGA fibers, which usually compromises the material's toughness, processability, and cost.

[0104] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material, characterized in that, The ingredients include: polybutylene succinate, modified polyglycolic acid fiber, chain extender and antioxidant; The modified polyglycolic acid fiber is a silane-modified polyglycolic acid fiber; The modified polyglycolic acid fiber accounts for 10-20% of the total mass of the polybutylene succinate and the modified polyglycolic acid fiber; The amount of chain extender added is 0-1% of the total mass of the polybutylene succinate and the modified polyglycolic acid fiber, and the amount of chain extender added is not 0. The amount of antioxidant added is 0-1% of the total mass of the polybutylene succinate and modified polyglycolic acid fiber, and the amount of antioxidant added is not 0.

2. The silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material according to claim 1, characterized in that, The preparation method of the silane-modified polyglycolic acid fiber is as follows: cut the polyglycolic acid fiber into 1-3 mm pieces to obtain short polyglycolic acid fibers; The chopped polyglycolic acid fibers were added to a silane coupling agent hydrolysis solution, magnetically stirred, and dried to obtain the silane-modified polyglycolic acid fibers.

3. The silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material according to claim 2, characterized in that, The method for preparing the silane coupling agent hydrolysis solution is as follows: under magnetic stirring, the silane coupling agent is added to a mixed solvent of ethanol and water, and its final concentration is controlled to be 1.0 wt%. The mixture is stirred evenly to obtain the silane coupling agent hydrolysis solution.

4. The silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material according to claim 3, characterized in that, The silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropylsilane, and γ-mercaptopropyltriethoxysilane.

5. The silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material according to claim 2, characterized in that, The mass ratio of the polyglycolic acid short-cut fibers to the silane coupling agent hydrolysis solution is 1:(5-15); The magnetic stirring process takes 6-12 hours.

6. The silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material according to claim 1, characterized in that, The antioxidant is selected from one of antioxidant 2112, antioxidant 1076 and antioxidant 1010.

7. A method for preparing a silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material as described in any one of claims 1-6, characterized in that, Includes the following steps: The silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material is prepared by melt blending polybutylene succinate, modified polyglycolic acid fiber, chain extender and antioxidant. The temperature of the melt blending is not higher than 180°C.

8. The method for preparing the silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material according to claim 7, characterized in that, The melt blending time is 3-8 minutes.

9. The method for preparing the silane-modified polyglycolic acid fiber-reinforced polybutylene succinate biodegradable composite material according to claim 7, characterized in that, During the melt blending process, the screw speed is 50 rpm.

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