Preparation method for bioactive glass fiber reinforced polylactic acid composite material

Abstract

The present invention relates to the technical field of biodegradable materials. Disclosed is a preparation method for a bioactive glass fiber reinforced polylactic acid composite material. The preparation method comprises the following steps: (1) subjecting bioactive glass fibers to a plasma treatment; (2) dissolving chitosan in an aqueous acetic acid solution, and then adding the treated bioactive glass fibers thereto, so as to obtain a mixed solution I; (3) adding a bioactive glass powder to an aqueous sodium tripolyphosphate solution, and then subjecting same to ball milling, so as to obtain a mixed solution II; (4) gradually adding the mixed solution II to the mixed solution I while stirring same, continuously stirring same overnight after the addition is finished, and then conducting filtering and drying, so as to obtain modified glass fibers; and (5) mixing the modified glass fibers with polylactic acid particles, and then subjecting the resulting mixture to melt extrusion, so as to obtain a polylactic acid composite material. In the present invention, by compounding modified bioactive glass fibers with a polylactic acid material, the mechanical strength of the composite material can be significantly improved.

Description

A method for preparing a bioactive glass fiber reinforced polylactic acid composite material Technical Field

[0001] This invention relates to the technical field of biodegradable materials, and in particular to a method for preparing a bioactive glass fiber reinforced polylactic acid composite material. Background Technology

[0002] Polylactic acid (PLA) or its derivatives (such as PLGA) have advantages such as good biodegradability, biocompatibility, and adjustable degradation rate as orthopedic implant materials. However, its weak mechanical properties, acidic environment caused by degradation products, and low bioactivity limit its application. Therefore, it is usually necessary to combine polylactic acid materials with other materials to enhance their performance.

[0003] Bioactive glass (BAG) possesses excellent bioactivity, rapidly inducing the formation of a hydroxyapatite (HA) layer in body fluids, promoting osteoblast adhesion and growth, and facilitating bone tissue regeneration. Simultaneously, bioactive glass exhibits good biocompatibility with human tissues, reducing post-implantation rejection and improving material biocompatibility. Therefore, combining bioactive glass with polylactic acid (PLA) can significantly improve multiple aspects of the material's properties, enhancing its application in the biomedical field.

[0004] However, bioactive glass is typically composited with polylactic acid (PLA) materials in powder form. Bioactive glass is prone to agglomeration and difficult to mix uniformly. Furthermore, the effect of bioactive glass powder on improving the mechanical strength of PLA materials is not significant, thus failing to meet the requirements for high-strength and high-rigidity PLA composites. For example, invention patent CN104524637A discloses a polymeric bioceramic composite nanoparticle biodegradable scaffold and its manufacturing method, including biodegradable medical devices such as scaffolds made from biodegradable polymeric bioceramic nanoparticle composites. The invention's medical device includes at least one type of bioceramic nanoparticle dispersed within (at least) one type of biodegradable polymer; the biodegradable polymer includes, but is not limited to, biodegradable polyester; the method and equipment for dispersing one or more bioceramic nanoparticles within the polymer are not entirely the same. The bioceramic nanoparticles here include, but are not limited to, amorphous calcium phosphate (ACP), dicalcium phosphate (DCP), tricalcium phosphate (TCP), hydroxyapatite pentacalcium (HAP), tetracalcium phosphate carbon monoxide (TTCP), and combinations or equivalent substances of the above. This method disperses bioceramic particles within a biodegradable polymer, which is highly susceptible to agglomeration and results in low mechanical strength. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing a polylactic acid composite material reinforced with bioactive glass fibers. By combining modified bioactive glass fibers with polylactic acid materials, the compatibility and dispersibility of bioactive glass fibers in the polylactic acid matrix are improved, while the bonding stability is enhanced. This further improves the mechanical strength and biocompatibility, making it more suitable for use as an orthopedic implant material.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention provides a method for preparing a bioactive glass fiber reinforced polylactic acid composite material, comprising the following steps:

[0008] (1) Plasma treatment of bioactive glass fibers with a diameter of 10-20 μm and a length of 1-3 mm;

[0009] (2) Dissolve chitosan in an aqueous acetic acid solution, and then add the treated bioactive glass fiber to obtain mixture I;

[0010] (3) Add bioactive glass powder to sodium tripolyphosphate aqueous solution and then ball mill to obtain mixture II;

[0011] (4) Add mixture II to mixture I gradually while stirring. After the mixture is finished, continue stirring overnight, then filter and dry to obtain modified glass fiber.

[0012] (5) Modified glass fiber and polylactic acid particles with a mass ratio of 5-20:100 are mixed and melt-extruded to obtain polylactic acid composite material.

[0013] Bioactive glass is made into fibers and then composited with polylactic acid (PLA). Since glass fibers have high tensile strength and modulus, the introduction of bioactive glass fibers into the composite material can significantly improve the tensile and flexural strength of PLA. Furthermore, BAG fibers also have good bioactivity and biocompatibility. Therefore, the resulting composite material can be better used as an orthopedic implant material.

[0014] However, bioactive glass fibers and polylactic acid (PLA) materials present greater compatibility issues and also exhibit a certain degree of agglomeration. This invention addresses this by plasma-treating bioactive glass fibers, resulting in an abundance of carboxyl and hydroxyl groups on the fiber surface, which improves their compatibility with PLA materials. Furthermore, the treated bioactive glass fibers can react with chitosan through active groups. After treatment in a dilute acid solvent, chitosan transforms from a highly coiled molecular conformation to an extended molecular chain conformation, allowing extended chitosan molecular chains to be grafted onto the surface of the bioactive glass fibers. Subsequently, by adding bioactive glass powder modified with sodium tripolyphosphate, cross-linking occurs on the grafted chains, fixing the bioactive glass particles to the surface of the bioactive glass fibers. The spatial spacing formed by the chitosan molecular chains helps reduce agglomeration and improve dispersibility. In addition, the introduction of chitosan macromolecules can improve the mechanical strength of composite materials. Furthermore, the good compatibility between chitosan and polylactic acid molecules, as well as the covalent bonding between active groups, can greatly improve the bonding between bioactive glass fibers and polylactic acid. The bonding stability formed by the molecular chain entanglement of bioactive glass particles is even higher, which can further enhance the mechanical strength.

[0015] Preferably, in step (1), the bioactive glass fiber is obtained by melting and drawing bioactive glass powder.

[0016] Preferably, in step (1), the plasma treatment is performed using oxygen and argon in a volume ratio of 1-3:1, with a gas flow rate of 10-50 cm³. 3 The processing pressure is 10-100 Pa, the processing temperature is 40-60℃, the processing power is 50-200 W, and the processing time is 5-20 min.

[0017] Preferably, in step (2), the mass concentration of the acetic acid aqueous solution is 1-2%.

[0018] Preferably, in step (2), the ratio of the amount of chitosan, aqueous acetic acid solution and treated bioactive glass fiber added is 80-100 mg: 50 mL: 1 g.

[0019] Preferably, in step (3), the concentration of the sodium tripolyphosphate aqueous solution is 40-60 mg / mL; and the ratio of the amount of bioactive glass powder to the amount of sodium tripolyphosphate aqueous solution is 0.07-0.1 g: 1 mL.

[0020] Preferably, in step (3), the particle size of the bioactive glass powder is 30-50 nm.

[0021] Preferably, in step (3), the ball milling is performed at a speed of 100-200 rpm for 10-30 minutes.

[0022] Preferably, in step (4), the stirring speed is 500-800 rpm and the addition time of mixture II is 40-60 min.

[0023] Preferably, in step (5), the mass ratio of the modified glass fiber to polylactic acid particles is 5-20:100, more preferably 10-20:100.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) Bioactive glass fiber has good bioactivity and biocompatibility. In addition, due to the high tensile strength and modulus of glass fiber, it can significantly improve the tensile strength and flexural strength of PLA when combined with polylactic acid.

[0026] (2) By first grafting extended chitosan molecular chains onto the surface of bioactive glass fibers, and then adding bioactive glass powder modified by sodium tripolyphosphate coating, cross-linking can be carried out on the grafted chains, fixing the bioactive glass particles onto the surface of the bioactive glass fibers, and forming spatial intervals through the chitosan molecular chains, which is beneficial to reduce agglomeration and improve dispersibility.

[0027] (3) The introduction of chitosan as a macromolecule can improve the mechanical strength of the composite material. Furthermore, through the good compatibility between chitosan and polylactic acid molecules, as well as the covalent bond between active groups, the binding between bioactive glass fiber and polylactic acid can be greatly improved. The binding stability formed by the molecular chain entanglement of bioactive glass particles is higher, which can further enhance the mechanical strength. Detailed Implementation

[0028] The technical solution of the present invention will be illustrated below with specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0029] A method for preparing a bioactive glass fiber reinforced polylactic acid composite material includes the following steps:

[0030] (1) Place the bioactive glass powder in a crucible and heat it to 1200-1400℃ to completely melt it, forming a homogeneous glass melt. Maintain the molten state for 30-50 minutes to eliminate bubbles and ensure uniform composition. Melt the molten glass melt and draw it into fibers, simultaneously cooling it with nitrogen. Then, ultrasonically clean and dry it with ethanol, and cut it to obtain bioactive glass (BAG) fibers with a diameter of 10-20 μm and a length of 1-3 mm. Next, treat the bioactive glass fibers with plasma using oxygen and argon at a volume ratio of 1-3:1 and a gas flow rate of 10-50 cm³. 3 The processing pressure is 10-100 Pa, the processing temperature is 40-60℃, the processing power is 50-200 W, and the processing time is 5-20 min.

[0031] (2) Dissolve chitosan in an aqueous acetic acid solution with a mass concentration of 1-2%, then add the treated bioactive glass fiber and stir for 30-60 minutes. The ratio of chitosan, aqueous acetic acid solution and treated glass fiber is 80-100 mg: 50 mL: 1 g to obtain mixture I.

[0032] (3) Add bioactive glass powder to a sodium tripolyphosphate aqueous solution with a concentration of 40-60 mg / mL. The ratio of bioactive glass powder to sodium tripolyphosphate aqueous solution is 0.07-0.1 g: 1 mL. Then, ball mill at a speed of 100-200 rpm for 10-30 min to obtain mixture II.

[0033] (4) Gradually add mixture II to mixture I while stirring at a speed of 500-800 rpm. The volume ratio of mixture II to mixture I is 1:1. The addition time of mixture II is controlled at 40-60 min. After the addition is completed, continue stirring overnight. Then filter and dry to obtain modified glass fiber.

[0034] (5) Modified glass fiber and polylactic acid particles with a mass ratio of 5-20:100 are mixed and melt-extruded to obtain polylactic acid composite material.

[0035] In a specific embodiment of the present invention, in step (1), the particle size of the bioactive glass powder is nanometer or micrometer.

[0036] In a specific embodiment of the present invention, in step (2), the degree of deacetylation of chitosan is 90% or higher, and the weight-average molecular weight is 100,000 to 300,000.

[0037] In a specific embodiment of the present invention, in step (3), the particle size of the bioactive glass powder is 30-50 nm.

[0038] In a specific embodiment of the present invention, in step (4), the addition rate of mixture II is constant.

[0039] In a specific embodiment of the present invention, in step (5), the weight-average molecular weight of the polylactic acid particles is 200,000 to 400,000.

[0040] In a specific embodiment of the present invention, in step (5), the temperature of mixing and melt extruding the modified glass fiber and polylactic acid particles is 170-190°C.

[0041] Example 1

[0042] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 15±1 μm and a length of 2 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 2:1 at a flow rate of 25 cm⁻¹. 3 The processing speed is 1 / min, the processing pressure is 60Pa, the processing temperature is 50℃, the processing power is 120W, and the processing time is 15min.

[0043] (2) Dissolve 100 mg chitosan (degree of deacetylation of 95% and weight average molecular weight of 100,000) in 50 mL of acetic acid aqueous solution with a mass concentration of 1%, and then add 1 g of treated bioactive glass fiber and stir for 30 min to obtain mixture I.

[0044] (3) Add 3.5g of bioactive glass powder (45S5) with a particle size of 30-50nm and an average particle size of 45nm to 50mL of sodium tripolyphosphate aqueous solution with a concentration of 60mg / mL. After stirring evenly, ball mill at 140rpm for 25min to obtain mixture II.

[0045] (4) Add mixture II to mixture I gradually while stirring at 600 rpm. The volume ratio of mixture II to mixture I is 1:1. The total addition time of mixture II is controlled to be 45 min. After completion, continue stirring overnight. Then, filter, wash with ethanol aqueous solution, and dry to obtain modified glass fiber.

[0046] (5) Modified glass fiber and polylactic acid particles (weight average molecular weight of 300,000) with a mass ratio of 10:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain polylactic acid composite material.

[0047] Example 2

[0048] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 12±1 μm and a length of 3 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 3:1 at a flow rate of 35 cm⁻¹. 3 The processing speed is 150 min, the processing pressure is 50 Pa, the processing temperature is 50 °C, the processing power is 150 W, and the processing time is 15 min.

[0049] (2) Dissolve 100 mg chitosan (degree of deacetylation of 95% and weight average molecular weight of 100,000) in 50 mL of acetic acid aqueous solution with a mass concentration of 1%, and then add 1 g of treated bioactive glass fiber and stir for 30 min to obtain mixture I.

[0050] (3) Add 3.5g of bioactive glass powder (45S5) with a particle size of 30-50nm and an average particle size of 45nm to 50mL of sodium tripolyphosphate aqueous solution with a concentration of 60mg / mL. After stirring evenly, ball mill at 140rpm for 25min to obtain mixture II.

[0051] (4) Add mixture II to mixture I gradually while stirring at 600 rpm. The volume ratio of mixture II to mixture I is 1:1. The total addition time of mixture II is controlled to be 45 min. After completion, continue stirring overnight. Then, filter, wash with ethanol aqueous solution, and dry to obtain modified glass fiber.

[0052] (5) Modified glass fiber and polylactic acid particles (weight average molecular weight of 300,000) with a mass ratio of 10:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain polylactic acid composite material.

[0053] Example 3

[0054] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 15±1 μm and a length of 2 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 2:1 at a flow rate of 25 cm⁻¹. 3 The processing speed is 1 / min, the processing pressure is 60Pa, the processing temperature is 50℃, the processing power is 120W, and the processing time is 15min.

[0055] (2) Dissolve 100 mg chitosan (degree of deacetylation of 95% and weight average molecular weight of 100,000) in 50 mL of acetic acid aqueous solution with a mass concentration of 1%, and then add 1 g of treated bioactive glass fiber and stir for 30 min to obtain mixture I.

[0056] (3) Add 4g of bioactive glass powder (45S5) with a particle size of 30-50nm and an average particle size of 35nm to 50mL of sodium tripolyphosphate aqueous solution with a concentration of 50mg / mL, and then ball mill at 200rpm for 20min to obtain mixture II.

[0057] (4) Add mixture II to mixture I gradually while stirring at 600 rpm. The volume ratio of mixture II to mixture I is 1:1. The total addition time of mixture II is controlled to be 60 min. After completion, continue stirring overnight. Then, filter, wash with ethanol aqueous solution, and dry to obtain modified glass fiber.

[0058] (5) Modified glass fiber and polylactic acid particles (weight average molecular weight of 300,000) with a mass ratio of 15:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain polylactic acid composite material.

[0059] Example 4

[0060] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 15±1 μm and a length of 2 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 2:1 at a flow rate of 25 cm⁻¹. 3 The processing speed is 1 / min, the processing pressure is 60Pa, the processing temperature is 50℃, the processing power is 120W, and the processing time is 15min.

[0061] (2) Dissolve 80 mg of chitosan (degree of deacetylation of 95% and weight-average molecular weight of 100,000) in 50 mL of acetic acid aqueous solution with a mass concentration of 2%, and then add 1 g of treated bioactive glass fiber and stir for 40 min to obtain mixture I.

[0062] (3) Add 5g of bioactive glass powder (45S5) with a particle size of 30-50nm and an average particle size of 35nm to 50mL of sodium tripolyphosphate aqueous solution with a concentration of 40mg / mL, and then ball mill at 200rpm for 30min to obtain mixture II.

[0063] (4) Add mixture II to mixture I gradually while stirring at 800 rpm. The volume ratio of mixture II to mixture I is 1:1. The total addition time of mixture II is controlled to be 40 min. After completion, continue stirring overnight. Then, filter, wash with ethanol aqueous solution, and dry to obtain modified glass fiber.

[0064] (5) Modified glass fiber and polylactic acid particles (weight average molecular weight of 300,000) with a mass ratio of 20:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain polylactic acid composite material.

[0065] Comparative Example 1

[0066] The difference from Example 1 is that bioactive glass fiber and polylactic acid are directly composited.

[0067] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 15±1 μm and a length of 2 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 2:1 at a flow rate of 25 cm⁻¹. 3 The processing speed is 1 / min, the processing pressure is 60Pa, the processing temperature is 50℃, the processing power is 120W, and the processing time is 15min.

[0068] (2) The treated bioactive glass fiber and polylactic acid particles with a mass ratio of 10:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain a polylactic acid composite material.

[0069] Comparative Example 2

[0070] The difference from Example 1 is that chitosan has a lower degree of deacetylation and a larger molecular weight.

[0071] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 15±1 μm and a length of 2 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 2:1 at a flow rate of 25 cm⁻¹. 3 The processing speed is 1 / min, the processing pressure is 60Pa, the processing temperature is 50℃, the processing power is 120W, and the processing time is 15min.

[0072] (2) Dissolve 100 mg chitosan (80% degree of deacetylation and 500,000 weight-average molecular weight) in 50 mL of 1% acetic acid aqueous solution, then add 1 g of treated bioactive glass fiber and stir for 30 min to obtain mixture I.

[0073] (3) Add 3.5g of bioactive glass powder (45S5) with a particle size of 30-50nm and an average particle size of 45nm to 50mL of sodium tripolyphosphate aqueous solution with a concentration of 60mg / mL. After stirring evenly, ball mill at 140rpm for 25min to obtain mixture II.

[0074] (4) Add mixture II to mixture I gradually while stirring at 600 rpm. The volume ratio of mixture II to mixture I is 1:1. The total addition time of mixture II is controlled to be 45 min. After completion, continue stirring overnight. Then, filter, wash with ethanol aqueous solution, and dry to obtain modified glass fiber.

[0075] (5) Modified glass fiber and polylactic acid particles (weight average molecular weight of 300,000) with a mass ratio of 10:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain polylactic acid composite material.

[0076] Comparative Example 3

[0077] The difference from Example 1 is that the bioactive glass powder is added after being treated with chitosan.

[0078] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 15±1 μm and a length of 2 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 2:1 at a flow rate of 25 cm⁻¹. 3 The processing speed is 1 / min, the processing pressure is 60Pa, the processing temperature is 50℃, the processing power is 120W, and the processing time is 15min.

[0079] (2) Dissolve 100 mg of chitosan (degree of deacetylation of 95% and weight-average molecular weight of 100,000) in 50 mL of acetic acid aqueous solution with a mass concentration of 1% to obtain mixture I.

[0080] (3) Add 3.5g of bioactive glass powder (45S5) with a particle size of 30-50nm and an average particle size of 45nm to 50mL of sodium tripolyphosphate aqueous solution with a concentration of 60mg / mL. After stirring evenly, ball mill at 140rpm for 25min to obtain mixture II.

[0081] (4) Add mixture II to mixture I gradually while stirring at 600 rpm. The volume ratio of mixture II to mixture I is 1:1. The total addition time of mixture II is controlled to be 45 min. After completion, add 1 g of the treated bioactive glass fiber and continue stirring overnight. Then filter, wash with ethanol aqueous solution, and dry to obtain modified glass fiber.

[0082] (5) Modified glass fiber and polylactic acid particles (weight average molecular weight of 300,000) with a mass ratio of 10:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain polylactic acid composite material.

[0083] Comparative Example 4

[0084] The difference from Example 1 is that the fiber size is too large.

[0085] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 30±1 μm and a length of 5 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 2:1 at a flow rate of 25 cm⁻¹. 3 The processing speed is 1 / min, the processing pressure is 60Pa, the processing temperature is 50℃, the processing power is 120W, and the processing time is 40min.

[0086] (2) Dissolve 100 mg chitosan (degree of deacetylation of 95% and weight average molecular weight of 100,000) in 50 mL of acetic acid aqueous solution with a mass concentration of 1%, and then add 1 g of treated bioactive glass fiber and stir for 30 min to obtain mixture I.

[0087] (3) Add 3.5g of bioactive glass powder (45S5) with a particle size of 30-50nm and an average particle size of 45nm to 50mL of sodium tripolyphosphate aqueous solution with a concentration of 60mg / mL. After stirring evenly, ball mill at 140rpm for 25min to obtain mixture II.

[0088] (4) Add mixture II to mixture I gradually while stirring at 600 rpm. The volume ratio of mixture II to mixture I is 1:1. The total addition time of mixture II is controlled to be 45 min. After completion, continue stirring overnight. Then, filter, wash with ethanol aqueous solution, and dry to obtain modified glass fiber.

[0089] (5) Modified glass fiber and polylactic acid particles (weight average molecular weight of 300,000) with a mass ratio of 10:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain polylactic acid composite material.

[0090] Comparative Example 5

[0091] The difference from Example 1 is that the concentration of Mixture II was too high.

[0092] (1) Bioactive glass powder (45S5) was heated to 1300℃ to completely melt it and held in the molten state for 30 min. Then, it was melt-drawn into fibers while being cooled with nitrogen. Afterwards, it was ultrasonically cleaned with ethanol, dried, and cut to obtain bioactive glass (BAG) fibers with a diameter of 15±1 μm and a length of 2 mm. The bioactive glass fibers were then treated with plasma using oxygen and argon in a volume ratio of 2:1 at a flow rate of 25 cm⁻¹. 3 The processing speed is 1 / min, the processing pressure is 60Pa, the processing temperature is 50℃, the processing power is 120W, and the processing time is 15min.

[0093] (2) Dissolve 100 mg chitosan (degree of deacetylation of 95% and weight average molecular weight of 100,000) in 50 mL of acetic acid aqueous solution with a mass concentration of 1%, and then add 1 g of treated bioactive glass fiber and stir for 30 min to obtain mixture I.

[0094] (3) Add 5.5g of bioactive glass powder (45S5) with a particle size of 30-50nm and an average particle size of 45nm to 50mL of sodium tripolyphosphate aqueous solution with a concentration of 75mg / mL. After stirring evenly, ball mill at 140rpm for 25min to obtain mixture II.

[0095] (4) Add mixture II to mixture I gradually while stirring at 600 rpm. The volume ratio of mixture II to mixture I is 1:1. The total addition time of mixture II is controlled to be 45 min. After completion, continue stirring overnight. Then, filter, wash with ethanol aqueous solution, and dry to obtain modified glass fiber.

[0096] (5) Modified glass fiber and polylactic acid particles (weight average molecular weight of 300,000) with a mass ratio of 10:100 were melt-blended at 170°C and extruded using a twin-screw extruder to obtain polylactic acid composite material.

[0097] The polylactic acid composite materials in Examples 1-4 and Comparative Examples 1-5 were used to prepare specimens by injection molding. The flexural performance test standard was in accordance with GB / T 9341-2008, and the specimen size was 80mm×10mm×4mm. The tensile performance test standard was in accordance with GB / T 1040.1-2018, and the specimen preparation standard was in accordance with GB / T1040.2-2022. The specimen size was l3: 75mm, l1: 30mm, r: 30mm, l2: 58mm, b2: 10mm, b1: 5mm, h: 3mm, L0: 25mm.

[0098] Table 1

[0099] Flexural modulus (GPa) Flexural strength (MPa) Tensile strength (MPa) Example 1 4.61 10.28 8.3 Example 2 4.71 14.78 7.9 Example 3 5.21 26.89 5.2 Example 4 5.01 21.09 0.6 Comparative Example 1 3.77 0.56 6.8 Comparative Example 2 4.29 1.48 0.5 Comparative Example 3 3.88 2.57 1.9 Comparative Example 4 4.41 02.67 6.7 Comparative Example 5 4.19 5.87 3.4

[0100] As shown in Table 1, the bioactive glass fiber in this invention, after being modified with chitosan and bioactive glass particles, is then composited with polylactic acid (PLA). This significantly improves the compatibility and dispersibility with PLA, while also enhancing the mechanical strength and biocompatibility of PLA. In contrast, the bioactive glass fiber in Comparative Example 1, without modification, was only treated with plasma before being composited with PLA, resulting in a significantly reduced mechanical strength of the resulting composite material.

[0101] Furthermore, in Comparative Example 2, the use of chitosan with a low degree of deacetylation and a large molecular weight resulted in the chitosan macromolecules failing to exhibit an extended molecular chain conformation after acetic acid treatment. Instead, they primarily coated the surface of the bioactive glass fibers, failing to form effective spatial intervals. This led to excessive aggregation during subsequent loading of bioactive glass particles, ultimately affecting the dispersibility of the composite material and reducing its mechanical strength. In Comparative Example 3, the addition of bioactive glass particles after cross-linking with chitosan and sodium tripolyphosphate also resulted in aggregation on the bioactive glass fibers and hindered the interweaving of chitosan and polylactic acid macromolecules. Consequently, the compatibility of the bioactive glass fibers with the polylactic acid material decreased, and the mechanical strength was also reduced. In Comparative Example 4, the excessively large size of the bioactive glass fibers resulted in a poorer modification effect, particularly significantly impacting their compatibility with the polylactic acid material, thus affecting the performance of the composite material. In Comparative Example 5, the excessive concentration of bioactive glass powder and sodium tripolyphosphate in the mixture II will lead to excessive cross-linking and local agglomeration on the surface of bioactive glass fibers, resulting in a decrease in the mechanical strength of the composite material, similar to Comparative Examples 2-3.

[0102] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made using the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing a bioactive glass fiber reinforced polylactic acid composite material, characterized in that, Includes the following steps: (1) Plasma treatment of bioactive glass fibers with a diameter of 10-20 μm and a length of 1-3 mm; (2) Dissolve chitosan in an aqueous acetic acid solution, and then add the treated bioactive glass fiber to obtain mixture I; (3) Add bioactive glass powder to sodium tripolyphosphate aqueous solution and then ball mill to obtain mixture II; (4) Add mixture II to mixture I gradually while stirring. After the mixture is finished, continue stirring overnight, then filter and dry to obtain modified glass fiber. (5) Modified glass fiber and polylactic acid particles with a mass ratio of 5-20:100 are mixed and melt-extruded to obtain polylactic acid composite material.

2. The method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to claim 1, characterized in that, In step (1), the plasma treatment is performed using a mixture of oxygen and argon gas at a flow rate of 10-50 cm³. 3 The processing pressure is 10-100 Pa, the processing temperature is 40-60℃, and the processing time is 5-20 min.

3. The method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to claim 1, characterized in that, In step (2), the degree of deacetylation of the chitosan is 90% or higher, and the weight-average molecular weight is 100,000 to 300,000.

4. The method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to claim 1, characterized in that, In step (2), the mass concentration of the acetic acid aqueous solution is 1-2%.

5. A method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to any one of claims 1-4, characterized in that, In step (2), the ratio of the amount of chitosan, acetic acid aqueous solution and treated bioactive glass fiber added is 80-100mg:50mL:1g.

6. The method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to claim 1, characterized in that, In step (3), the concentration of the sodium tripolyphosphate aqueous solution is 40-60 mg / mL.

7. The method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to claim 1, characterized in that, In step (3), the ratio of the amount of bioactive glass powder to sodium tripolyphosphate aqueous solution added is 0.07-0.1g:1mL.

8. The method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to claim 1, 6, or 7, characterized in that, In step (3), the particle size of the bioactive glass powder is 30-50 nm.

9. The method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to claim 1, characterized in that, In step (3), the ball milling is performed at a speed of 100-200 rpm for 10-30 minutes.

10. A method for preparing the bioactive glass fiber reinforced polylactic acid composite material according to claim 1 or 9, characterized in that, In step (4), the volume ratio of the mixture II to the mixture I is 1:1; the stirring speed is 500-800 rpm; and the addition time of the mixture II is 40-60 min.