Anti-aging high-barrier medical composite film and preparation process thereof

Abstract

The application discloses an anti-aging high-barrier medical composite film and a preparation process thereof, and belongs to the technical field of composite films. The hard template-alkali etching process is adopted to prepare hollow thorn-shaped alumina powder. The hollow structure is matched with the surface thorn-shaped protruding morphology, which is different from the conventional solid spherical and flaky inorganic fillers. The powder has both hollow cavities and surface radial thorn protruding structures. When the powder is filled in the middle barrier layer of the composite film, on the one hand, the surface thorn protrusions can form anchoring and penetrating structures inside the polypropylene resin matrix, increasing the contact interface between the fillers and the matrix; on the other hand, a large number of thorn-shaped skeletons are interlaced and overlapped with each other, and a continuous and multiple winding labyrinthine permeation channel is constructed in the film layer, greatly extending the diffusion distance of oxygen and water vapor. Meanwhile, the hollow cavities can adsorb and retain permeated small molecules, and the double mechanisms are cooperated to significantly improve the oxygen and moisture resistance of the film, and realize high-efficiency barrier.

Description

Technical Field

[0001] This invention belongs to the field of composite membrane technology, specifically an anti-aging high-barrier medical composite membrane and its preparation process. Background Technology

[0002] In the field of medical device and pharmaceutical flexible packaging, polypropylene film is widely used as a substrate for sterile medical packaging due to its excellent chemical stability, resistance to ethylene oxide sterilization, low leaching risk, and good processability. However, pure polypropylene is a non-polar polyolefin material with a large amount of free volume between its molecular chains, making it susceptible to permeation and diffusion of oxygen and water vapor, resulting in insufficient inherent barrier properties. Furthermore, the presence of tertiary carbon atoms in the polypropylene molecular chain makes it prone to oxidative degradation under conditions of light exposure, moist heat sterilization, and long-term storage. This causes film yellowing, decreased mechanical strength, and a shortened packaging protection period, making it difficult to meet the requirements for long-term sterile storage of highly sensitive drugs and precision medical devices.

[0003] Currently, the mainstream methods for improving the barrier properties of polypropylene films fall into two categories: one is to use multilayer composites of polar barrier resins such as EVOH and PA. This system has excellent barrier effects, but the polar resins have poor compatibility with polypropylene, making melt flow matching difficult during three-layer co-extrusion, and causing interlayer delamination easily after film bending and heating; the other is to construct tortuous permeation paths by adding inorganic fillers such as talc, nano-silica, and ordinary alumina. Conventional solid inorganic fillers have obvious defects: poor interfacial compatibility between the filler and the non-polar polypropylene matrix, easy agglomeration of powder, and excessive filling will degrade the toughness of the film; ordinary solid particles have limited effect in extending the gas diffusion path, resulting in insufficient improvement in barrier performance. Existing technologies rarely use hollow, spiky alumina as a barrier filler, and there is a lack of integrated solutions for organic modification of the filler surface and interfacial bonding between the filler and the polyolefin matrix.

[0004] In addition, most existing medical polypropylene films rely solely on the direct mixing of small molecule antioxidants to achieve aging resistance. These small molecule additives are prone to migration and precipitation during high-temperature extrusion and long-term storage, which does not meet the compliance requirements for low precipitates in pharmaceutical packaging. At the same time, a single formulation system cannot simultaneously take into account the heat-sealing compatibility of the inner layer, the barrier sealing ability of the middle layer, and the anti-aging and hydrophobic properties of the outer layer. Most single-layer or simple blend films on the market have limited functions and cannot simultaneously achieve long-lasting anti-aging and high gas barrier properties.

[0005] Therefore, developing a medical polypropylene composite film with uniformly dispersed fillers, stable interlayer bonding, excellent oxygen and moisture barrier capabilities, long-lasting anti-aging properties, and low risk of additive migration is of significant engineering value for improving the long-term storage stability of medical packaging and expanding the application scenarios of high-end pharmaceutical packaging. Summary of the Invention

[0006] The purpose of this invention is to provide an anti-aging, high-barrier medical composite membrane and its preparation process. Hollow, spiky alumina powder is prepared using a hard template-alkali etching process. The hollow structure combined with the spiky protrusions on the surface distinguishes it from conventional solid spherical or sheet-like inorganic fillers. This powder possesses both a hollow inner cavity and a radially protruding surface structure. When filled into the middle barrier layer of the composite membrane, the spiky protrusions on the surface can form an anchoring and penetrating structure into the polypropylene resin matrix, increasing the contact interface between the filler and the matrix. Furthermore, the numerous interlocking spiky skeletons construct continuous, multi-layered, labyrinthine permeation channels within the membrane layer, significantly extending the diffusion distance of oxygen and water vapor. Simultaneously, the hollow cavity can adsorb and retain small permeation molecules. This dual mechanism synergistically enhances the oxygen and moisture barrier performance of the membrane, achieving highly efficient barrier properties.

[0007] The objective of this invention can be achieved through the following technical solutions: A preparation process for an anti-aging high-barrier medical composite membrane includes the following steps: Step 1: Using hexadecyltrimethylammonium bromide as a mesoporous template, ammonia water is used to catalyze the hydrolysis and condensation of tetraethyl orthosilicate to obtain silica particles.

[0008] Step 2: Using silica microspheres as a hard template, hexadecyltrimethylammonium bromide and urea as morphology modifiers, aluminum source precursors are deposited on the surface of silica particle templates by hydrolysis of aluminum isopropoxide to obtain spiky alumina powder.

[0009] Step 3: Using γ-methacryloxypropyltrimethoxysilane as a modifier, the silane undergoes hydrolysis under acidic conditions and covalently grafts with the hydroxyl groups on the surface of the spiky alumina powder to obtain modified spiky alumina powder.

[0010] Step 4: Blend the modified spiky alumina powder, maleic anhydride-grafted polypropylene, and initiator, then extrude the mixture through a twin-screw melt reaction and granulate it to obtain the intermediate layer sealing masterbatch.

[0011] Step 5: Prepare homopolymer polypropylene inner layer masterbatch and polypropylene surface layer masterbatch with added hydrophobic additives and antioxidants respectively; melt co-extrude the inner layer masterbatch, barrier sealing intermediate masterbatch, and surface layer masterbatch into three layers to finally obtain an anti-aging high barrier medical composite membrane.

[0012] Furthermore, the specific preparation steps for silica particles are as follows: Hexadecyltrimethylammonium bromide and ammonia were added to a reaction vessel and stirred for 30-40 min at 20-25℃ and 500-600 r / min. Then tetraethyl orthosilicate was added and the reaction was continued for 6-8 h. The mixture was centrifuged at 8000-9000 r / min for 5-8 min. The filter cake was transferred to isopropanol and ammonium nitrate and reacted at 80-90℃ for 24 h. The mixture was then freeze-dried under vacuum at -20℃ for 12-14 h to obtain silica particles.

[0013] Furthermore, the ratio of hexadecyltrimethylammonium bromide, ammonia, tetraethyl orthosilicate, isopropanol, and ammonium nitrate is 30-35g: 2-3L: 170-180mL: 1.5-1.7L: 14-16g.

[0014] Furthermore, the specific preparation steps for the spiky alumina powder are as follows: Hexadecyltrimethylammonium bromide, urea, silica particles, and deionized water were added to a reaction vessel and stirred for 30-40 minutes at 20-25°C and 500-600 rpm. Isopropanol and aluminum isopropoxide were then added, and stirring was continued for another 30-40 minutes. The mixture was then heated to 70-80°C and reacted for 16-18 hours. After filtration, the filter cake was washed 2-4 times with deionized water and dried under vacuum at 60-80°C for 1-2 hours. The cake was then transferred to a muffle furnace and calcined at 550-600°C for 6-8 hours. The calcined powder was dispersed in a 2-3 mol / L sodium hydroxide solution and stirred at 75-85°C for 8-12 hours to etch away the silica core. The powder was then centrifuged at 6000-7000 rpm for 3-5 minutes, washed with water until neutral, and dried under vacuum at 60-70°C for 1-2 hours to obtain spiky alumina powder.

[0015] Furthermore, the ratio of hexadecyltrimethylammonium bromide, urea, silica particles, deionized water, isopropanol, and aluminum isopropoxide is 20-30g: 12-14g: 8-10g: 450-500mL: 16-18mL: 25-30g.

[0016] Furthermore, the specific preparation steps for the modified spiky alumina powder are as follows: Add spiky alumina powder, anhydrous ethanol, and deionized water to a reaction vessel and stir for 20-30 min at 50-60℃ and 500-600 r / min. Then add γ-methacryloyloxypropyltrimethoxysilane, adjust the pH to 3-4 with hydrochloric acid solution, and continue stirring for 6-8 h. Filter the mixture, wash the precipitate 2-4 times with deionized water and anhydrous ethanol, and vacuum dry at 60-70℃ for 1-2 h to obtain modified spiky alumina powder.

[0017] Furthermore, the ratio of spiky alumina powder, anhydrous ethanol, deionized water, and γ-methacryloyloxypropyltrimethoxysilane is 25-30g: 1.5-1.7L: 3-4L: 110-112mL.

[0018] Furthermore, the specific preparation steps of the intermediate layer blocking masterbatch are as follows: Modified spiky alumina powder, maleic anhydride-grafted polypropylene, and di-tert-butyl peroxide are added to a high-speed mixer and mixed at 800-900 r / min for 10-12 min. The mixture is then transferred to a twin-screw extruder and melt-copolymerized at 185-190℃ and 250-300 r / min for 12-14 min. The mixture is then granulated to obtain the intermediate layer sealing masterbatch.

[0019] Furthermore, the ratio of modified spiky alumina powder, maleic anhydride-grafted polypropylene, and di-tert-butyl peroxide is 10-20g: 70-80g: 3-4g.

[0020] Furthermore, the inner layer masterbatch is obtained by melt blending homopolymer polypropylene and erucamide at a mass ratio of 60-70:1-2, followed by extrusion granulation.

[0021] Furthermore, the surface masterbatch is obtained by melt blending and extrusion granulation of polypropylene, hydrophobic silica, erucamide and hindered phenolic antioxidant in a mass ratio of 60-70:1-2:1-2:1-2.

[0022] Furthermore, the inner layer masterbatch, the middle layer sealing masterbatch, and the surface layer masterbatch are melt-co-extruded to obtain an anti-aging high-barrier medical composite membrane.

[0023] The beneficial effects of this invention are: 1. This invention uses a hard template-alkali etching process to prepare hollow spiky alumina powder. The hollow structure combined with the spiky protrusions on the surface distinguishes it from conventional solid spherical and sheet-like inorganic fillers. This powder has both a hollow inner cavity and a radial spiky structure on the surface. When it is filled into the middle barrier layer of a composite membrane, on the one hand, the spiky protrusions on the surface can form an anchoring and interpenetrating structure into the polypropylene resin matrix, increasing the contact interface between the filler and the matrix; on the other hand, a large number of spiky skeletons interlock and overlap, constructing a continuous, multi-layered, labyrinthine permeation channel inside the membrane, greatly extending the diffusion distance of oxygen and water vapor; at the same time, the hollow cavity can adsorb and retain permeation small molecules. The dual mechanisms work synergistically to significantly improve the oxygen and moisture barrier performance of the membrane, achieving high-efficiency barrier. 2. This invention utilizes γ-methacryloxypropyltrimethoxysilane to covalently modify the surface of spiky alumina powder, introducing polymerizable carbon-carbon double bonds into the surface of the spiky alumina powder. In the subsequent melt processing stage, the modified powder can undergo an interfacial reaction with maleic anhydride-grafted polypropylene, significantly improving the interfacial compatibility between inorganic fillers and non-polar polypropylene matrix, inhibiting powder agglomeration, reducing interfacial voids between fillers and resin, and simultaneously enhancing the overall mechanical strength of the composite film. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: A preparation process for an anti-aging high-barrier medical composite membrane, comprising the following steps: S1: Add 30g of hexadecyltrimethylammonium bromide and 2L of ammonia water to a reaction vessel, stir for 30min at 20℃ and 500r / min, then add 170mL of tetraethyl orthosilicate, continue the reaction for 6h, centrifuge at 8000r / min for 5min, transfer the filter cake to 1.5L of isopropanol and 14g of ammonium nitrate, react at 80℃ for 24h, and freeze-dry under vacuum at -20℃ for 12h to obtain silica particles.

[0026] S2: Add 20g hexadecyltrimethylammonium bromide, 12g urea, 8g silica particles and 450mL deionized water to a reaction vessel, stir for 30min at 20℃ and 500r / min, then add 16mL isopropanol and 25g aluminum isopropoxide, continue stirring for 30min, heat to 70℃, continue the reaction for 16h, filter, wash the filter cake twice with deionized water, vacuum dry at 60℃ for 1h, transfer to a muffle furnace, calcine at 550℃ for 6h, disperse the calcined powder in 2mol / L sodium hydroxide solution, stir at 75℃ for 8h to etch away the silica core, centrifuge at 6000r / min for 3min, wash with water until neutral, vacuum dry at 60℃ for 1h to obtain spiky alumina powder.

[0027] S3: Add 25g of spiky alumina powder, 1.5L of anhydrous ethanol and 3L of deionized water to a reaction vessel, stir for 20min at 50℃ and 500r / min, then add 110mL of γ-methacryloyloxypropyltrimethoxysilane, adjust the pH to 3 with hydrochloric acid solution, continue stirring for 6h, filter, wash the precipitate twice with deionized water and anhydrous ethanol, and vacuum dry at 60℃ for 1h to obtain modified spiky alumina powder.

[0028] S4: Add 10g of modified spiky alumina powder, 70g of maleic anhydride-grafted polypropylene, and 3g of di-tert-butyl peroxide to a high-speed mixer and mix at 800r / min for 10min. Transfer to a twin-screw extruder and melt copolymerize at 185℃ and 250r / min for 12min. Granulate to obtain the intermediate layer blocking masterbatch.

[0029] S5: 60g homopolymer polypropylene and 1g erucamide are melt-blended and extruded and granulated using a twin-screw extruder to obtain the inner layer masterbatch; 60g polypropylene, 1g hydrophobic silica, 1g erucamide and 1g hindered phenolic antioxidant are melt-blended and extruded and granulated using a twin-screw extruder to obtain the surface layer masterbatch; the inner layer masterbatch, the intermediate layer sealing masterbatch and the surface layer masterbatch are melt-co-extruded to obtain an anti-aging high-barrier medical composite film.

[0030] Example 2: A preparation process for an anti-aging high-barrier medical composite membrane, comprising the following steps: S1: Add 32.5g of cetyltrimethylammonium bromide and 2.5L of ammonia water to a reaction vessel, stir for 35min at 22.5℃ and 550r / min, then add 175mL of tetraethyl orthosilicate, continue the reaction for 7h, centrifuge at 8500r / min for 6.5min, transfer the filter cake to 1.6L of isopropanol and 15g of ammonium nitrate, react at 85℃ for 24h, and freeze-dry under vacuum at -20℃ for 13h to obtain silica particles.

[0031] S2: Add 25g hexadecyltrimethylammonium bromide, 13g urea, 9g silica particles and 475mL deionized water to a reaction vessel, stir for 35min at 22.5℃ and 550r / min, then add 17mL isopropanol and 27.5g aluminum isopropoxide, continue stirring for 35min, heat to 75℃, continue the reaction for 17h, filter, wash the filter cake three times with deionized water, vacuum dry at 70℃ for 1.5h, transfer to a muffle furnace, calcine at 575℃ for 7h, disperse the calcined powder in 2.5mol / L sodium hydroxide solution, stir at 80℃ for 10h to etch away the silica core, centrifuge at 6500r / min for 4min, wash with water until neutral, vacuum dry at 65℃ for 1.5h to obtain spiky alumina powder.

[0032] S3: Add 27.5g of spiky alumina powder, 1.6L of anhydrous ethanol and 3.5L of deionized water to a reaction vessel, stir for 25min at 55℃ and 550r / min, then add 111mL of γ-methacryloyloxypropyltrimethoxysilane, adjust the pH to 3.5 with hydrochloric acid solution, continue stirring for 7h, filter, wash the precipitate three times with deionized water and anhydrous ethanol, and vacuum dry at 65℃ for 1.5h to obtain modified spiky alumina powder.

[0033] S4: Add 15g of modified spiky alumina powder, 75g of maleic anhydride-grafted polypropylene, and 3.5g of di-tert-butyl peroxide to a high-speed mixer and mix at 850r / min for 11min. Transfer the mixture to a twin-screw extruder and melt copolymerize at 187.5℃ and 275r / min for 13min. Granulate the mixture to obtain the intermediate layer sealing masterbatch.

[0034] S5: 65g homopolymer polypropylene and 1.5g erucamide are melt-blended and extruded and granulated using a twin-screw extruder to obtain the inner layer masterbatch; 65g polypropylene, 1.5g hydrophobic silica, 1.5g erucamide and 1.5g hindered phenolic antioxidant are melt-blended and extruded and granulated using a twin-screw extruder to obtain the surface layer masterbatch; the inner layer masterbatch, the intermediate layer sealing masterbatch and the surface layer masterbatch are melt-co-extruded to obtain an anti-aging high-barrier medical composite film.

[0035] Example 3: A preparation process for an anti-aging high-barrier medical composite membrane, comprising the following steps: S1: Add 35g of cetyltrimethylammonium bromide and 3L of ammonia water to a reaction vessel, stir for 40min at 25℃ and 600r / min, then add 180mL of tetraethyl orthosilicate, continue the reaction for 8h, centrifuge at 9000r / min for 8min, transfer the filter cake to 1.7L of isopropanol and 16g of ammonium nitrate, react at 90℃ for 24h, and freeze-dry under vacuum at -20℃ for 14h to obtain silica particles.

[0036] S2: Add 30g hexadecyltrimethylammonium bromide, 14g urea, 10g silica particles and 500mL deionized water to a reaction vessel, stir for 40min at 25℃ and 600r / min, then add 18mL isopropanol and 30g aluminum isopropoxide, continue stirring for 40min, heat to 80℃, continue the reaction for 18h, filter, wash the filter cake 4 times with deionized water, vacuum dry at 80℃ for 2h, transfer to a muffle furnace, calcine at 600℃ for 8h, disperse the calcined powder in 3mol / L sodium hydroxide solution, stir at 85℃ for 12h to etch away the silica core, centrifuge at 7000r / min for 5min, wash with water until neutral, vacuum dry at 70℃ for 2h to obtain spiky alumina powder.

[0037] S3: Add 30g of spiky alumina powder, 1.7L of anhydrous ethanol and 4L of deionized water to a reaction vessel, stir at 60℃ and 600r / min for 30min, then add 112mL of γ-methacryloyloxypropyltrimethoxysilane, adjust the pH to 4 with hydrochloric acid solution, continue stirring for 8h, filter, wash the precipitate 4 times with deionized water and anhydrous ethanol, and vacuum dry at 70℃ for 2h to obtain modified spiky alumina powder.

[0038] S4: Add 20g of modified spiky alumina powder, 80g of maleic anhydride-grafted polypropylene, and 4g of di-tert-butyl peroxide to a high-speed mixer and mix at 900r / min for 12min. Transfer to a twin-screw extruder and melt copolymerize at 190℃ and 300r / min for 14min. Granulate to obtain the intermediate layer blocking masterbatch.

[0039] S5: 70g homopolymer polypropylene and 2g erucamide are melt-blended and extruded and granulated using a twin-screw extruder to obtain the inner layer masterbatch; 70g polypropylene, 2g hydrophobic silica, 2g erucamide and 2g hindered phenolic antioxidant are melt-blended and extruded and granulated using a twin-screw extruder to obtain the surface layer masterbatch; the inner layer masterbatch, the intermediate layer sealing masterbatch and the surface layer masterbatch are melt-co-extruded to obtain an anti-aging high-barrier medical composite film.

[0040] Comparative Example 1: Based on Example 3, the modified spiky alumina powder in step S4 was replaced with the spiky alumina powder prepared in step S2.

[0041] Comparative Example 2: Based on Example 3, the spiky alumina powder in step S3 was replaced with commercially available alumina powder.

[0042] Performance tests were conducted on Examples 1-3 and Comparative Examples 1-2. The peel strength, water vapor transmission rate, and oxygen transmission rate of the anti-aging high-barrier medical composite film were tested before and after boiling at 121°C for 15 minutes. Peel strength was determined according to General Chapter 4004 of the 2025 edition of the Chinese Pharmacopoeia, Part IV, "Determination of Peel Strength of Plastics"; water vapor transmission rate was determined according to General Chapter 4010 of the 2025 edition of the Chinese Pharmacopoeia, Part IV, "Determination of Water Vapor Transmission Rate of Pharmaceutical Packaging Materials"; and oxygen transmission rate was determined according to General Chapter 4007 of the 2025 edition of the Chinese Pharmacopoeia, Part IV, "Determination of Gas Transmission Rate of Pharmaceutical Packaging Materials". The results are shown in Table 1. Table 1

[0043] As shown in Table 1, the spiky alumina powder without silane modification in Comparative Example 1 lacked double-bonded active groups and could not covalently bond with maleic anhydride-grafted PP. The powder agglomerated severely, and there were a large number of micro-gaps at the resin-filler interface. The peel strength was only 1.6245 before cooking and dropped to 1.5018 after cooking, which was significantly lower than that of the Example. The water vapor and oxygen permeation was about twice that of the Example. The interface cracked during high-temperature cooking, and the permeation further doubled, resulting in a significant deterioration in barrier performance. This proves that silane double bond modification is the key to improving interfacial bonding and inhibiting permeation.

[0044] In Comparative Example 2, conventional solid commercially available alumina was replaced. Without a hollow inner cavity or radial spike anchoring structure, and only simple particle filling, it was impossible to construct a continuous labyrinthine barrier channel. The peel strength before cooking was only 1.3127, significantly lower than the example. Before cooking, the water vapor permeability was 1.1574 and the oxygen permeability was 0.9856, showing a significant difference. After high-temperature cooking, the interface debonded, and the barrier performance declined sharply, proving that the unique hollow spike morphology is the basis of the high-barrier core structure.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A preparation process for an anti-aging high-barrier medical composite membrane, characterized in that, Includes the following steps: Step 1: Using hexadecyltrimethylammonium bromide as a mesoporous template, ammonia water catalyzes the hydrolysis and condensation of tetraethyl orthosilicate to obtain silica particles; Step 2: Using silica microspheres as a hard template, hexadecyltrimethylammonium bromide and urea as morphology modifiers, aluminum source precursors are deposited on the surface of silica particle templates by hydrolysis of aluminum isopropoxide to obtain spiky alumina powder. Step 3: Using γ-methacryloxypropyltrimethoxysilane as a modifier, the silane undergoes hydrolysis under acidic conditions and covalently grafts with the hydroxyl groups on the surface of the spiky alumina powder to obtain modified spiky alumina powder. Step 4: The modified spiky alumina powder, maleic anhydride-grafted polypropylene and initiator are blended, extruded by twin-screw melt reaction, and granulated to obtain the intermediate layer sealing masterbatch. Step 5: Prepare homopolymer polypropylene inner layer masterbatch and polypropylene surface layer masterbatch with added hydrophobic additives and antioxidants respectively; melt co-extrude the inner layer masterbatch, barrier sealing intermediate masterbatch, and surface layer masterbatch into three layers to finally obtain an anti-aging high barrier medical composite membrane.

2. The preparation process of an anti-aging high-barrier medical composite membrane according to claim 1, characterized in that, The specific preparation steps for the silica particles are as follows: Hexadecyltrimethylammonium bromide and ammonia were added to a reaction vessel and stirred for 30-40 min at 20-25℃ and 500-600 r / min. Then tetraethyl orthosilicate was added and the reaction was continued for 6-8 h. The mixture was centrifuged at 8000-9000 r / min for 5-8 min. The filter cake was transferred to isopropanol and ammonium nitrate and reacted at 80-90℃ for 24 h. The mixture was then freeze-dried under vacuum at -20℃ for 12-14 h to obtain silica particles.

3. The preparation process of an anti-aging high-barrier medical composite membrane according to claim 2, characterized in that, The ratio of hexadecyltrimethylammonium bromide, ammonia, tetraethyl orthosilicate, isopropanol, and ammonium nitrate is 30-35g: 2-3L: 170-180mL: 1.5-1.7L: 14-16g.

4. The preparation process of an anti-aging high-barrier medical composite membrane according to claim 1, characterized in that, The specific preparation steps for the spiky alumina powder are as follows: Hexadecyltrimethylammonium bromide, urea, silica particles, and deionized water were added to a reaction vessel and stirred for 30-40 minutes at 20-25°C and 500-600 rpm. Isopropanol and aluminum isopropoxide were then added, and stirring was continued for another 30-40 minutes. The mixture was then heated to 70-80°C and reacted for 16-18 hours. After filtration, the filter cake was washed 2-4 times with deionized water and dried under vacuum at 60-80°C for 1-2 hours. The cake was then transferred to a muffle furnace and calcined at 550-600°C for 6-8 hours. The calcined powder was dispersed in a 2-3 mol / L sodium hydroxide solution and stirred at 75-85°C for 8-12 hours to etch away the silica core. The powder was then centrifuged at 6000-7000 rpm for 3-5 minutes, washed with water until neutral, and dried under vacuum at 60-70°C for 1-2 hours to obtain spiky alumina powder.

5. The preparation process of an anti-aging high-barrier medical composite membrane according to claim 4, characterized in that, The ratio of hexadecyltrimethylammonium bromide, urea, silica particles, deionized water, isopropanol, and aluminum isopropoxide is 20-30g: 12-14g: 8-10g: 450-500mL: 16-18mL: 25-30g.

6. The preparation process of an anti-aging high-barrier medical composite membrane according to claim 1, characterized in that, The specific preparation steps for the modified spiky alumina powder are as follows: Add spiky alumina powder, anhydrous ethanol, and deionized water to a reaction vessel and stir for 20-30 min at 50-60℃ and 500-600 r / min. Then add γ-methacryloyloxypropyltrimethoxysilane, adjust the pH to 3-4 with hydrochloric acid solution, and continue stirring for 6-8 h. Filter the mixture, wash the precipitate 2-4 times with deionized water and anhydrous ethanol, and vacuum dry at 60-70℃ for 1-2 h to obtain modified spiky alumina powder.

7. The preparation process of an anti-aging high-barrier medical composite membrane according to claim 6, characterized in that, The ratio of the spiky alumina powder, anhydrous ethanol, deionized water, and γ-methacryloyloxypropyltrimethoxysilane is 25-30g: 1.5-1.7L: 3-4L: 110-112mL.

8. The preparation process of an anti-aging high-barrier medical composite membrane according to claim 1, characterized in that, The specific preparation steps of the intermediate layer sealing masterbatch are as follows: Modified spiky alumina powder, maleic anhydride-grafted polypropylene, and di-tert-butyl peroxide are added to a high-speed mixer and mixed at 800-900 r / min for 10-12 min. The mixture is then transferred to a twin-screw extruder and melt-copolymerized at 185-190℃ and 250-300 r / min for 12-14 min. The mixture is then granulated to obtain the intermediate layer sealing masterbatch. The ratio of the modified spiky alumina powder, maleic anhydride-grafted polypropylene, and di-tert-butyl peroxide is 10-20g: 70-80g: 3-4g.

9. The preparation process of an anti-aging high-barrier medical composite membrane according to claim 1, characterized in that, The inner layer masterbatch is obtained by melt blending homopolymer polypropylene and erucamide in a mass ratio of 60-70:1-2 and then extruding and granulating. The surface layer masterbatch is obtained by melt blending polypropylene, hydrophobic silica, erucamide, and hindered phenolic antioxidant in a mass ratio of 60-70:1-2:1-2:1-2 and then extruding and granulating. The inner layer masterbatch, the intermediate layer sealing masterbatch, and the surface layer masterbatch are melt co-extruded to obtain an anti-aging high-barrier medical composite film.

10. A high-barrier, anti-aging medical composite membrane, characterized in that, It is prepared by the preparation process described in any one of claims 1-9.

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