Graphene composite fiber medical elastic fabric glove

Abstract

The application discloses a graphene composite fiber medical elastic fabric glove, and belongs to the technical field of medical polymer materials. Raw materials thereof include medical grade ethylene-alpha-olefin polyolefin elastomer, branched polyethylene, graphene modified branched polyolefin and the like; wherein the graphene modified branched polyolefin is prepared through catalyst covalent anchoring-in-situ chain walking polymerization, realizing good dispersion of graphene in the matrix. The glove solves the pain points in the prior art, such as easy agglomeration of graphene, decline of barrier performance after stretching, insufficient biological safety and the like, and through synergistic effect of raw materials and structure optimization, mechanical strength, elastic recovery, dynamic barrier, antibacterial and antistatic performances are simultaneously improved. The product has no latex allergy risk, low heavy metal residue and excellent biocompatibility, and can meet the needs of high-end medical scenes such as operating rooms and clinical laboratories, and has industrialization adaptability and environmental protection value.

Description

Technical Field

[0001] This invention relates to the field of medical polymer materials technology, and in particular to a graphene composite fiber medical elastic fabric glove. Background Technology

[0002] Medical gloves are core protective consumables in clinical diagnosis, surgical procedures and medical care. Their performance is directly related to the safety of medical staff and patients. They must meet multiple stringent requirements, including protective barrier properties, wearing comfort, mechanical stability and biocompatibility. Currently, the mainstream medical gloves on the market mainly include latex gloves, nitrile gloves, PVC gloves, and traditional polyolefin gloves. Latex gloves were once widely used due to their excellent elasticity and fit, but natural latex proteins can easily trigger type I immediate-type allergic reactions, posing a safety hazard to medical staff and patients with allergies. Nitrile gloves solve the allergy problem, but their raw materials rely on butadiene polymerization, resulting in poor aging resistance and difficulty in degradation after disposal, which does not conform to global environmental policy trends. PVC gloves pose a risk of phthalate plasticizer leaching, which may cause skin irritation and potential health hazards with long-term contact. Traditional polyolefin gloves (such as polyethylene and polypropylene) have advantages such as good biocompatibility, no allergy risk, and environmental recyclability, but are limited by the linear structure and low mechanical strength of the material itself. They generally have defects such as insufficient elasticity, high permanent deformation rate, poor tear and puncture resistance, and weak barrier properties against pathogens and chemicals. They can only be used for low-load basic protection and cannot meet the needs of high-end medical scenarios such as operating rooms and laboratories.

[0003] To address the performance shortcomings of traditional polyolefin gloves, the industry has been exploring the use of nanomaterials to modify and improve their overall performance. Among these, graphene, with its ultra-high mechanical strength, two-dimensional sheet barrier structure, natural antibacterial properties, and good electrical conductivity, has become an ideal functional filler for modifying polyolefin medical gloves. However, existing technical solutions for graphene-modified polyolefin gloves still face numerous insurmountable technical bottlenecks. On the one hand, graphene sheets exhibit a strong π-π stacking effect and have extremely poor compatibility with non-polar polyolefin matrices. Existing methods such as physical blending and silane coupling agent surface modification can only achieve macroscopic dispersion of graphene, failing to prevent its agglomeration in the matrix to form micron-sized impurities. This not only fails to provide nano-reinforcement and barrier effects but also becomes stress concentration points, leading to deterioration of the glove's mechanical properties and frequent clogging of the spinneret during melt spinning, affecting the stability of continuous production. On the other hand, in existing modification schemes, graphene and the polyolefin matrix are mostly bonded by weak van der Waals forces, resulting in weak interfacial bonding. During the stretching process of wearing the glove, graphene sheets are prone to slippage, deflection, and stacking, causing the original barrier structure to be destroyed and the barrier rate to drop sharply. This makes it impossible to achieve continuous protection under dynamic wearing conditions, which is the core pain point that makes it difficult for existing graphene-modified gloves to achieve large-scale clinical application.

[0004] Furthermore, existing graphene modification technologies face dual challenges related to biosafety and process controllability: in some in-situ polymerization modification schemes, metal residues from catalysts and co-catalysts are difficult to completely remove, far exceeding the heavy metal limits for medical materials; and the small molecule dispersants, coupling agents, and antibacterial agents added to improve dispersibility and antibacterial properties are prone to migration and precipitation, potentially causing cytotoxicity and skin sensitization risks. Therefore, developing a medical glove manufacturing technology that can achieve nanoscale monodispersion of graphene in a polyolefin matrix, strengthen interfacial bonding, ensure dynamic protective stability, and maintain biosafety has become an urgent need in the field of medical polymer materials. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a graphene composite fiber medical elastic fabric glove.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a graphene composite fiber medical elastic fabric glove, comprising the following components by weight: medical-grade ethylene-α-olefin polyolefin elastomer: 65-85 parts, branched polyethylene: 10-30 parts, graphene-modified branched polyolefin: 0.3-6 parts, antioxidant: 0.1-0.5 parts, lubricant: 0.1-0.3 parts; The preparation method of the graphene-modified branched polyolefin is as follows: (1) Under nitrogen protection, the α-diimine nickel catalyst was dissolved in anhydrous dichloromethane to prepare a solution with a concentration of 0.3-0.5 mol / L. The solution was cooled to 0°C in an ice bath, and phosphorus tribromide was added. The temperature of the system was controlled not to exceed 5°C during the addition. After the addition was completed, the solution was brought back to room temperature and stirred for 3-4 hours. After the reaction was completed, excess phosphorus tribromide was quenched with ice water in an ice bath. The organic phase was separated and washed with saturated sodium bicarbonate solution until neutral. The organic phase was washed twice with saturated brine, dried with anhydrous sodium sulfate, filtered, concentrated under reduced pressure to 1 / 10 of the original volume, and precipitated by adding anhydrous n-hexane. The precipitate was filtered, recrystallized twice with anhydrous n-hexane, and dried under vacuum to obtain the benzyl bromide-substituted α-diimine nickel catalyst. The chemical reaction equation is as follows: This step is an SN2 bimolecular nucleophilic substitution reaction of the benzylic hydroxyl group, using phosphorus tribromide as the halogenating agent. First, the lone pair electrons of the oxygen atom of the terminal benzylic hydroxymethyl group of the catalyst attack the electron-deficient phosphorus atom in phosphorus tribromide, forming a phosphorus-oxygen bond intermediate, which converts the difficult-to-leave hydroxyl group into the easily-leaving dibromophosphoroxy group, and releases a bromide anion. Subsequently, the bromide anion undergoes a nucleophilic attack from the back side of the benzylic carbon atom, removing the leaving group to complete the substitution, and finally generating a benzylic bromide-substituted α-diimine nickel catalyst. (2) Under nitrogen protection, the α-diimide nickel catalyst substituted with benzyl bromide was added to anhydrous DMF, potassium phthalimide was added, the temperature was raised to 50-60℃, and the reaction was stirred for 6-8 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and deionized water was added to the filtrate to precipitate the precipitate. After filtration again, the precipitate was washed three times alternately with deionized water and anhydrous ethanol, and dried to obtain the phthalimide-protected catalyst intermediate. The chemical reaction equation is as follows: This step follows the nucleophilic substitution mechanism of the Gabriel amination reaction. The phthalimide anion dissociated from potassium phthalimide acts as a strong nucleophile, attacking the sp3 hybridized carbon atom at the benzyl position in the benzyl bromide-substituted catalyst, resulting in SN2 nucleophilic substitution. The bromide anion then leaves as a leaving group, generating a phthalimide-protected catalyst intermediate. (3) Add the phthalimide-protected catalyst intermediate to anhydrous ethanol, add hydrazine hydrate, heat to 40-50℃, stir for 1-3 h, filter while hot to remove the phthalimide hydrazine precipitate, concentrate the filtrate under reduced pressure to 1 / 5 of the original volume, add anhydrous n-hexane to precipitate, filter and dry to obtain the terminal amino α-diimide nickel catalyst; the chemical reaction equation is as follows: This step is the hydrazine deprotection of the Gabriel reaction. The phthalimide protecting group undergoes a nucleophilic addition-elimination reaction with hydrazine hydrate. The amino group of hydrazine hydrate first attacks the carbonyl carbon atom of phthalimide, forming a four-membered ring transition state and then rearranging to generate a highly stable phthalohydrazide precipitate. At the same time, the free primary amino group at the catalyst terminal is released. The mild reaction conditions can avoid the deactivation of the catalyst active center, and the by-products can be completely removed by filtration. (4) Disperse monolayer graphene oxide in anhydrous DMF and sonicate for 30-60 min to obtain a graphene oxide dispersion with a concentration of 1-3 mg / ml. Add thionyl chloride / DMF mixture to the dispersion, heat to 65-75℃ under nitrogen protection, reflux for 12-24 h, filter, wash 3 times with anhydrous tetrahydrofuran, and dry to obtain acyl-chlorinated graphene oxide. The graphene oxide in this step has carboxyl active sites on its edge. Thionyl chloride acts as an acylation reagent and reacts with the carboxyl group. The hydroxyl oxygen of the carboxyl group first attacks the sulfur atom of thionyl chloride to form an active acyl thioester intermediate. Subsequently, the intermediate undergoes intramolecular rearrangement, removing sulfur dioxide and hydrogen chloride molecules, and quantitatively converting the carboxyl group into a highly reactive acyl chloride group, providing an active site for the covalent anchoring of the subsequent catalyst. DMF acts as a phase transfer catalyst to accelerate the reaction process, and the anhydrous environment avoids the hydrolysis and deactivation of the acyl chloride group. (5) Disperse acyl chloride graphene oxide in anhydrous toluene, add terminal amino α-diimine nickel catalyst and anhydrous triethylamine under nitrogen protection, heat to 40-60℃, stir for 6-12h, collect the precipitate by centrifugation after the reaction, wash the precipitate with ethanol 3-5 times, and dry to obtain catalyst covalently anchored graphene oxide; This step is the amidation reaction of acyl chloride and primary amine. The terminal amino α-diimine nickel catalyst acts as a nucleophile to attack the carbonyl carbon atom of the acyl chloride group on the surface of acyl chloride graphene oxide, and a nucleophilic addition-elimination reaction occurs. First, a tetrahedral transition state is formed, and then the hydrogen chloride molecule is removed to generate a stable amide bond, thereby achieving covalent anchoring of the α-diimine nickel catalyst on the surface of graphene oxide sheets; Anhydrous triethylamine added to the system acts as an acid-binding agent, which can quickly neutralize the hydrogen chloride generated in the reaction, avoid amino protonation deactivation and acid hydrolysis of imine ligands, and ensure the efficient progress of the amidation reaction; (6) Under nitrogen protection, the covalently anchored graphene oxide was placed in a high-pressure reactor, anhydrous toluene was added and stirred until evenly dispersed, then methylaluminoxane was added, and high-purity ethylene gas was continuously introduced to maintain the system pressure at 0.5-1.5 MPa. The temperature was raised to 20-60℃, and the polymerization reaction was stirred for 0.8-2.5 h. After the reaction was completed, 5% (v / v) of acidified methanol was added to terminate the reaction. After filtration, the crude product was obtained. This step is based on the α-diimine nickel-catalyzed ethylene chain-walking coordination polymerization mechanism, accompanied by the reduction process of graphene oxide. First, methylaluminoxane... Alkane acts as a co-catalyst, undergoing halohydrocarbon exchange with a nickel catalyst covalently anchored to the graphene surface to form cationic nickel active centers, providing reaction sites for ethylene polymerization. Subsequently, ethylene monomers continuously undergo coordination insertion between nickel-carbon bonds to achieve chain growth. Simultaneously, the nickel active centers undergo directional "chain walking" along the polymer carbon chain through β-H elimination, and then reinsert ethylene monomers, generating a large number of methyl branches and long branches on the polymer backbone, forming highly branched polyolefins with a dendritic topology. The degree of branching can be precisely controlled by polymerization temperature and ethylene pressure. During polymerization, the Ni(II) active centers can also simultaneously reduce graphene oxide to reduced graphene oxide. Furthermore, because the polymerization active centers are completely fixed on the graphene surface, each polyolefin molecular chain generated is covalently grafted to the graphene sheets through amide bonds. (7) The crude product was loaded into a cellulose extraction sleeve with a pore size of 220 nm and placed in a Soxhlet extractor. Anhydrous ethanol / deionized water mixture was used as the extraction solvent and the product was heated and refluxed under nitrogen protection for 12-24 h to complete the first extraction. The product after the first extraction was taken out, dried under vacuum at 30 °C, and then loaded back into the cellulose extraction sleeve and placed in a Soxhlet extractor. Chromatographically pure hexane was used as the extraction solvent and the product was heated and refluxed under nitrogen protection for 24-48 h to obtain graphene-modified branched polyolefin.

[0007] Preferably, the medical-grade ethylene-α-olefin polyolefin elastomer is an ethylene-octene copolymer with an octene mass fraction of 20%-35%, a melt flow rate of 0.5-5 g / 10 min at 190°C and 2.16 kg, and a Shore hardness of 50-70 A.

[0008] Preferably, the branched polyethylene is a long-chain branched polyethylene prepared by metallocene catalysis, with a melt flow rate of 0.3-3 g / 10 min at 190°C and 2.16 kg, and a density of 0.865-0.890 g / cm³. 3 Branching degree ≥ 0.3.

[0009] Preferably, the antioxidant refers to a mixture of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1.

[0010] Preferably, the lubricant refers to any one of sodium stearate, zinc stearate, and potassium stearate.

[0011] More preferably, the lubricant refers to zinc stearate.

[0012] Preferably, the α-diimine nickel catalyst in (1) has the following chemical structure: .

[0013] Preferably, the α-diimine nickel catalyst in (1) is prepared by the method described in the reference "Ethylene Polymerization Using α-Diimine Nickel Catalysts with Multiple Hydroxyl Groups and Their Supported Catalysts", DOI: 10.1007 / s10562-025-05261-9, and its synthetic route is as follows: .

[0014] Preferably, the molar ratio of α-diimine nickel catalyst and phosphorus tribromide in (1) is 1:0.7-0.8.

[0015] Preferably, the molar ratio of the benzyl bromide-substituted α-diimide nickel catalyst and the potassium phthalimide in (2) is 1:2.1-2.4.

[0016] Preferably, in (2), the benzyl bromide-substituted α-diimine nickel catalyst and anhydrous DMF are in a weight ratio of 1:10-20.

[0017] Preferably, the molar ratio of the phthalimide-protected catalyst intermediate to hydrazine hydrate in (3) is 1:2.1-2.4.

[0018] Preferably, in (3), the phthalimide-protected catalyst intermediate and anhydrous ethanol are in a weight ratio of 1:10-20.

[0019] Preferably, in (4), the weight ratio of monolayer graphene oxide and thionyl chloride is 1:20-30.

[0020] Preferably, the volume fraction of thionyl chloride in the thionyl chloride / DMF mixture in (4) is 90%.

[0021] Preferably, in (5), the acyl chloride graphene oxide, anhydrous toluene, terminal amino α-diimide nickel catalyst and anhydrous triethylamine are in a weight ratio of 1:20-40:0.08-0.25:0.05-0.1.

[0022] Preferably, the covalently anchored graphene oxide, anhydrous toluene, and methylaluminoxane in the catalyst in (6) are in a weight ratio of 1:200-500:2-6.

[0023] Preferably, the volume ratio of anhydrous ethanol to deionized water in the anhydrous ethanol / deionized water mixture in (7) is 4:1.

[0024] Furthermore, the present invention also provides a method for preparing a graphene composite fiber medical elastic fabric glove, comprising the following steps: S1. Add medical-grade ethylene-octene polyolefin elastomer, branched polyolefin, graphene-modified branched polyolefin, antioxidant, and lubricant to a high-speed mixer and mix at 1000-2000 r / min for 5-10 min at room temperature to obtain a premix. Add the premix to a twin-screw extruder and set the temperatures as follows: Zone 1 100-120℃, Zone 2 120-140℃, Zone 3 140-160℃, Zone 4 170-190℃, Zone 5 170-180℃, die head temperature 170-180℃, and screw speed 120-200 r / min. After extrusion, the material is cooled by water, air-dried, pelletized, and dried to obtain composite granules. S2. The composite granules are added to a melt spinning machine and melt-extruded through a spinneret with 24-48 holes and a single hole diameter of 0.25-0.3 mm. The extruded filaments are cooled and shaped by side blowing. The cooled filaments are introduced into a drawing heat box through guide rollers for two-stage hot drawing. The total draw ratio is 3-6 times. The first-stage drawing temperature is 70-90℃ and the second-stage drawing temperature is 90-110℃. The drawn filaments are heat-set at 110℃ for 30 seconds, oiled, and then wound to obtain graphene composite polyolefin elastic fibers. S3. Graphene composite polyolefin elastic fibers are woven on a single-sided weft knitting machine to form a weft-knitted double-sided greige fabric. The greige fabric is then sent to a heat-setting machine for heat setting treatment. The setting temperature is 100-110℃ and the setting speed is 15-25m / min. After setting, the fabric is ultrasonically cleaned twice with deionized water for 10 minutes each time to remove surface dust and oil. It is then dried with hot air circulation to obtain graphene composite fiber elastic fabric. S4. The graphene composite fiber elastic fabric is laid flat on a glove forming machine, cut using a medical glove mold, and heat-sealed to obtain a glove blank. The glove blank is placed on a light inspection table and inspected one by one with light. Defective products with pinholes, poor heat sealing, or damage are removed. Qualified products are sent to an ethylene oxide sterilization cabinet. After sterilization, they are vacuum-packed to obtain a graphene composite fiber medical elastic fabric glove.

[0025] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention completely solves the industry problem of poor compatibility and easy agglomeration between graphene and polyolefin matrices through an innovative modification path of catalyst covalent anchoring-in-situ chain-walking polymerization. After terminal amino functionalization, the α-diimine nickel catalyst forms stable amide bonds with acyl chloride-oxidized graphene for anchoring. During polymerization, branched polyolefin chains grow in situ from the graphene surface, achieving nanoscale monodispersity of graphene. This covalent grafting structure not only shields the π-π stacking of graphene sheets but also strengthens interfacial bonding through molecular entanglement, significantly improving the material's mechanical properties. Simultaneously, it avoids spinneret clogging during spinning, ensuring continuous production stability and providing a structural basis for high-performance medical gloves.

[0026] 2. This invention overcomes the core problem of the precipitous drop in barrier performance of existing graphene-modified gloves after stretching, constructing a highly efficient barrier system that combines static and dynamic protection. Under normal conditions, the dispersed graphene sheets form regular "maze-like" channels, extending the penetration path of pathogens and chemicals. During dynamic stretching, the covalently grafted polyolefin chains drive the graphene sheets to align in an oriented manner, maintaining the integrity of the barrier channels and ensuring continuous protection while worn. This design requires no additional barrier additives, achieving high barrier performance solely through material structure optimization, fully meeting the protection needs of frequent stretching in clinical operations, and significantly improving the level of medical safety.

[0027] 3. This invention achieves a perfect balance between high performance and biosafety, fully complying with stringent medical device standards. Through a two-step Soxhlet extraction process, impurities such as catalyst metal residues and small-molecule additives are completely removed, reducing heavy metal residues to below medical limits. The raw material is medical-grade polyolefin free of latex protein and plasticizers. Combined with the physical antibacterial properties of graphene, there is no need to add small-molecule antibacterial agents, avoiding cytotoxicity and skin sensitization caused by precipitation. The product has low cytotoxicity, zero sensitization rate, and excellent biocompatibility, avoiding the safety hazards of traditional medical gloves from the source and making it suitable for long-term wear.

[0028] 4. This invention achieves a synergistic improvement in multiple properties, including high elasticity, antibacterial properties, and antistatic properties, breaking through the limitations of traditional polyolefin gloves with their single performance characteristics. Medical-grade ethylene-octene elastomer and long-chain branched polyethylene form a complementary entanglement network, which, combined with the reinforcing effect of graphene, gives the gloves both high elongation at break and excellent elastic recovery, extremely low permanent deformation rate, and a comfortable fit; the reduced graphene oxide sp... 2 The conjugated network endows the material with medical-grade antistatic properties, preventing electrostatic interference with precision instruments. At the same time, it achieves broad-spectrum and efficient antibacterial properties through physical cutting, without relying on chemical antibacterial agents. It is durable and safe, fully covering the needs of high-end medical scenarios. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with existing known technologies. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] The medical-grade ethylene-α-olefin polyolefin elastomers used in the examples and comparative examples were all ethylene-octene copolymers with an octene mass fraction of 20%-35%, a melt flow rate of 0.5-5 g / 10 min at 190°C and 2.16 kg, and a Shore hardness of 50-70 A. The branched polyolefins were all long-chain branched polyethylene prepared by metallocene catalysis, with a melt flow rate of 0.3-3 g / 10 min at 190°C and 2.16 kg, and a density of 0.865-0.890 g / cm³. 3 Branching degree ≥ 0.3.

[0031] Preparation Example 1: A specific preparation method for graphene-modified branched polyolefins, including the following steps: (1) Under nitrogen protection, 0.01 mol of α-diimine nickel catalyst was dissolved in anhydrous dichloromethane to prepare a solution with a concentration of 0.3 mol / L. The solution was cooled to 0°C in an ice bath, and 0.007 mol of phosphorus tribromide was added. The temperature of the system was controlled not to exceed 5°C during the addition. After the addition was completed, the solution was brought back to room temperature and stirred for 3 h. After the reaction was completed, ice water was added in an ice bath to quench the excess phosphorus tribromide. The organic phase was separated and washed with saturated sodium bicarbonate solution until neutral. The organic phase was washed twice with saturated brine, dried with anhydrous sodium sulfate, filtered, concentrated under reduced pressure to 1 / 10 of the original volume, and anhydrous n-hexane was added to precipitate the precipitate. After filtration, the precipitate was recrystallized twice with anhydrous n-hexane and dried under vacuum to obtain benzyl bromide-substituted α-diimine nickel catalyst. (2) Under nitrogen protection, 0.01 mol (10.57 g) of benzyl bromide-substituted α-diimide nickel catalyst was added to 105.72 g of anhydrous DMF, and 0.021 mol of potassium phthalimide was added. The temperature was raised to 50 °C and the reaction was stirred for 6 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and deionized water was added to the filtrate to precipitate the precipitate. After filtration again, the mixture was washed three times with deionized water and anhydrous ethanol, and dried to obtain the phthalimide-protected catalyst intermediate. (3) 0.01 mol (11.90 g) of phthalimide-protected catalyst intermediate was added to 119 g of anhydrous ethanol, 0.021 mol of hydrazine hydrate was added, the temperature was raised to 40 °C, and the reaction was stirred for 1 h. After the reaction was completed, the phthalimide precipitate was removed by hot filtration. The filtrate was concentrated under reduced pressure to 1 / 5 of the original volume, and anhydrous n-hexane was added to precipitate the precipitate. After filtration and drying, the α-diimide-terminated nickel catalyst was obtained. (4) 5g of monolayer graphene oxide was dispersed in anhydrous DMF and sonicated for 30min to obtain a graphene oxide dispersion with a concentration of 1mg / ml. A thionyl chloride / DMF mixture with a volume fraction of 90% (100g of thionyl chloride in the mixture) was added to the dispersion. The mixture was heated to 65℃ under nitrogen protection and refluxed for 12h. After filtration, the mixture was washed three times with anhydrous tetrahydrofuran and dried to obtain acyl-chlorinated graphene oxide. (5) 5g of acyl chloride graphene oxide was dispersed in 100g of anhydrous toluene. Under nitrogen protection, 0.4g of terminal amino α-diimine nickel catalyst and 0.25g of anhydrous triethylamine were added. The temperature was raised to 40℃ and the reaction was stirred for 6h. After the reaction was completed, the precipitate was collected by centrifugation, washed with ethanol 3 times, and dried to obtain graphene oxide covalently anchored by the catalyst. (6) Under nitrogen protection, 5g of covalently anchored graphene oxide was placed in a high-pressure reactor, 1kg of anhydrous toluene was added and stirred to disperse evenly, then 10g of methylaluminoxane was added, and high-purity ethylene gas was continuously introduced to maintain the system pressure at 0.5MPa. The temperature was raised to 20℃ and stirred for 0.8h to polymerize. After the reaction was completed, 5% by volume of acidified methanol was added to terminate the reaction. After filtration, the crude product was obtained. (7) The crude product was loaded into a cellulose extraction sleeve with a pore size of 220 nm and placed in a Soxhlet extractor. Anhydrous ethanol / deionized water mixture (volume ratio of anhydrous ethanol to deionized water of 4:1) was used as the extraction solvent. The product was heated and refluxed for 12 h under nitrogen protection to complete the first extraction. The product after the first extraction was taken out, dried under vacuum at 30 °C, and then loaded back into the cellulose extraction sleeve and placed in a Soxhlet extractor. Chromatographically pure hexane was used as the extraction solvent. The product was heated and refluxed for 24 h under nitrogen protection to obtain graphene-modified branched polyolefin.

[0032] Preparation Example 2: A specific preparation method for graphene-modified branched polyolefins, including the following steps: (1) Under nitrogen protection, 0.01 mol of α-diimine nickel catalyst was dissolved in anhydrous dichloromethane to prepare a solution with a concentration of 0.4 mol / L. The solution was cooled to 0°C in an ice bath and 0.0075 mol of phosphorus tribromide was added. The temperature of the system was controlled not to exceed 5°C during the addition. After the addition was completed, the solution was stirred at room temperature for 3.5 h. After the reaction was completed, ice water was added in an ice bath to quench the excess phosphorus tribromide. The organic phase was separated and washed with saturated sodium bicarbonate solution until neutral. The organic phase was washed twice with saturated brine, dried with anhydrous sodium sulfate, filtered, concentrated under reduced pressure to 1 / 10 of the original volume, and anhydrous n-hexane was added to precipitate the precipitate. After filtration, the precipitate was recrystallized twice with anhydrous n-hexane and dried under vacuum to obtain benzyl bromide-substituted α-diimine nickel catalyst. (2) Under nitrogen protection, 0.01 mol (10.57 g) of benzyl bromide-substituted α-diimide nickel catalyst was added to 160 g of anhydrous DMF, and 0.022 mol of potassium phthalimide was added. The temperature was raised to 55 °C and the reaction was stirred for 7 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and deionized water was added to the filtrate to precipitate the precipitate. After filtration again, the precipitate was washed three times alternately with deionized water and anhydrous ethanol and dried to obtain the phthalimide-protected catalyst intermediate. (3) 0.01 mol (11.90 g) of phthalimide-protected catalyst intermediate was added to 180 g of anhydrous ethanol, 0.023 mol of hydrazine hydrate was added, the temperature was raised to 45 °C, and the reaction was stirred for 2 h. After the reaction was completed, the phthalimide precipitate was removed by hot filtration. The filtrate was concentrated under reduced pressure to 1 / 5 of the original volume, and anhydrous n-hexane was added to precipitate the precipitate. After filtration and drying, the α-diimide-terminated nickel catalyst was obtained. (4) 5g of monolayer graphene oxide was dispersed in anhydrous DMF and sonicated for 45min to obtain a graphene oxide dispersion with a concentration of 2mg / ml. A thionyl chloride / DMF mixture with a volume fraction of 90% (125g of thionyl chloride in the mixture) was added to the dispersion. The temperature was raised to 70℃ under nitrogen protection and refluxed for 18h. After filtration, the mixture was washed three times with anhydrous tetrahydrofuran and dried to obtain acyl-chlorinated graphene oxide. (5) 5g of acyl chloride graphene oxide was dispersed in 150g of anhydrous toluene. Under nitrogen protection, 1g of terminal amino α-diimine nickel catalyst and 0.4g of anhydrous triethylamine were added. The temperature was raised to 50℃ and the reaction was stirred for 10h. After the reaction was completed, the precipitate was collected by centrifugation. The precipitate was washed 4 times with ethanol and dried to obtain covalently anchored graphene oxide. (6) Under nitrogen protection, 5g of covalently anchored graphene oxide was placed in a high-pressure reactor, 2kg of anhydrous toluene was added and stirred to disperse evenly, then 20g of methylaluminoxane was added, and high-purity ethylene gas was continuously introduced to maintain the system pressure at 1MPa. The temperature was raised to 40℃ and stirred for 1.5h for polymerization. After the reaction was completed, 5% by volume of acidified methanol was added to terminate the reaction. After filtration, the crude product was obtained. (7) The crude product was loaded into a cellulose extraction sleeve with a pore size of 220 nm and placed in a Soxhlet extractor. Anhydrous ethanol / deionized water mixture (volume ratio of anhydrous ethanol to deionized water of 4:1) was used as the extraction solvent. The product was heated and refluxed for 18 h under nitrogen protection to complete the first extraction. The product after the first extraction was taken out, dried under vacuum at 30 °C, and then loaded back into the cellulose extraction sleeve and placed in a Soxhlet extractor. Chromatographically pure hexane was used as the extraction solvent. The product was heated and refluxed for 36 h under nitrogen protection to obtain graphene-modified branched polyolefin.

[0033] Preparation Example 3: A specific preparation method for graphene-modified branched polyolefins, including the following steps: (1) Under nitrogen protection, 0.01 mol of α-diimine nickel catalyst was dissolved in anhydrous dichloromethane to prepare a solution with a concentration of 0.5 mol / L. The solution was cooled to 0°C in an ice bath, and 0.008 mol of phosphorus tribromide was added. The temperature of the system was controlled not to exceed 5°C during the addition. After the addition was completed, the solution was brought back to room temperature and stirred for 4 h. After the reaction was completed, excess phosphorus tribromide was quenched by adding ice water in an ice bath. The organic phase was separated and washed with saturated sodium bicarbonate solution until neutral. The organic phase was washed twice with saturated brine, dried with anhydrous sodium sulfate, filtered, concentrated under reduced pressure to 1 / 10 of the original volume, and precipitated by adding anhydrous n-hexane. After filtration, the precipitate was recrystallized twice with anhydrous n-hexane and dried under vacuum to obtain benzyl bromide-substituted α-diimine nickel catalyst. (2) Under nitrogen protection, 0.01 mol (10.57 g) of benzyl bromide-substituted α-diimide nickel catalyst was added to 211.4 g of anhydrous DMF, and 0.024 mol of potassium phthalimide was added. The temperature was raised to 60 °C and the reaction was stirred for 8 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and deionized water was added to the filtrate to precipitate the precipitate. After filtration again, the precipitate was washed three times alternately with deionized water and anhydrous ethanol and dried to obtain the phthalimide-protected catalyst intermediate. (3) 0.01 mol (11.90 g) of phthalimide-protected catalyst intermediate was added to 238 g of anhydrous ethanol, 0.024 mol of hydrazine hydrate was added, the temperature was raised to 50 °C, and the reaction was stirred for 3 h. After the reaction was completed, the phthalimide precipitate was removed by hot filtration. The filtrate was concentrated under reduced pressure to 1 / 5 of the original volume, and anhydrous n-hexane was added to precipitate the precipitate. After filtration and drying, the α-diimide-terminated nickel catalyst was obtained. (4) 5g of monolayer graphene oxide was dispersed in anhydrous DMF and sonicated for 60min to obtain a graphene oxide dispersion with a concentration of 3mg / ml. A thionyl chloride / DMF mixture with a volume fraction of 90% (150g of thionyl chloride in the mixture) was added to the dispersion. The mixture was heated to 75℃ under nitrogen protection and refluxed for 24h. After filtration, the mixture was washed three times with anhydrous tetrahydrofuran and dried to obtain acyl-chlorinated graphene oxide. (5) 5g of acyl chloride graphene oxide was dispersed in 200g of anhydrous toluene. Under nitrogen protection, 1.25g of terminal amino α-diimine nickel catalyst and 0.5g of anhydrous triethylamine were added. The temperature was raised to 60℃ and the reaction was stirred for 12h. After the reaction was completed, the precipitate was collected by centrifugation, washed with ethanol 5 times, and dried to obtain covalently anchored graphene oxide. (6) Under nitrogen protection, 5g of covalently anchored graphene oxide was placed in a high-pressure reactor, 2.5kg of anhydrous toluene was added and stirred to disperse evenly, then 30g of methylaluminoxane was added, and high-purity ethylene gas was continuously introduced to maintain the system pressure at 1.5MPa. The temperature was raised to 60℃ and stirred for 2.5h for polymerization. After the reaction was completed, 5% by volume of acidified methanol was added to terminate the reaction. After filtration, the crude product was obtained. (7) The crude product was loaded into a cellulose extraction sleeve with a pore size of 220 nm and placed in a Soxhlet extractor. Anhydrous ethanol / deionized water mixture (volume ratio of anhydrous ethanol to deionized water of 4:1) was used as the extraction solvent. The product was heated and refluxed under nitrogen protection for 24 h to complete the first extraction. The product after the first extraction was taken out, dried under vacuum at 30 °C, and then loaded back into the cellulose extraction sleeve and placed in a Soxhlet extractor. Chromatographically pure hexane was used as the extraction solvent. The product was heated and refluxed under nitrogen protection for 48 h to obtain graphene-modified branched polyolefin.

[0034] Comparative Preparation Example 1: The difference between Comparative Preparation Example 1 and Preparation Example 2 is that step (4) is omitted, and the acyl chloride graphene oxide in step (5) is replaced with graphene oxide.

[0035] Comparative Preparation Example 2: The difference between Comparative Preparation Example 2 and Preparation Example 2 is that steps (1)-(3) are omitted, and the terminal amino α-diimine nickel catalyst in step (5) is replaced with an α-diimine nickel catalyst.

[0036] Comparative Preparation Example 3: The difference between Comparative Preparation Example 3 and Preparation Example 2 is that graphene oxide was grafted and modified with a silane coupling agent and then melt-blended with branched polyethylene. The specific preparation method is as follows: (1) 5g of monolayer graphene oxide was dispersed in anhydrous ethanol and sonicated for 45min to obtain a dispersion with a concentration of 2mg / ml. 1g of KH550 silane coupling agent was added, and the temperature was raised to 70℃ under nitrogen protection and refluxed for 6h. After the reaction was completed, the mixture was centrifuged, washed 3 times with anhydrous ethanol, and dried to obtain silane-modified graphene oxide. (2) Mix 5g of silane-modified graphene oxide with 100g of branched polyethylene (branching degree ≥ 0.3, melt flow rate at 190℃, 0.55g / 10min at 2.16kg, density 0.873g / cm³). 3 The product was added to a twin-screw extruder, melt-grafted and extruded, granulated, and then extracted with hexane under Soxhlet reflux for 24 hours and dried to obtain graphene-modified branched polyolefin.

[0037] Example 1: A specific preparation method for a graphene composite fiber medical elastic fabric glove, comprising the following steps: S1. 650g of medical-grade ethylene-octene polyolefin elastomer, 100g of branched polyolefin, 3g of graphene-modified branched polyolefin prepared according to Preparation Example 1, 1g of antioxidant (a mixture of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1) and 1g of zinc stearate are added to a high-speed mixer and mixed at 1000r / min for 5min at room temperature to obtain a premix. The premix is ​​then added to a twin-screw extruder, with the temperatures set as follows: Zone 1 100℃, Zone 2 120℃, Zone 3 140℃, Zone 4 170℃, Zone 5 170℃, Die head temperature 170℃, and Screw speed 120r / min. The extruded material is then water-cooled, air-dried, pelletized, and dried to obtain composite granules. S2. The composite granules are added to a melt spinning machine and melt-extruded through a 24-hole spinneret with a single hole diameter of 0.25-0.3 mm. The extruded filaments are cooled and shaped by side blowing. The cooled filaments are introduced into a drawing heat box through guide rollers for two-stage hot drawing with a total draw ratio of 3 times. The first-stage drawing temperature is 70℃ and the second-stage drawing temperature is 90℃. The drawn filaments are then heat-set at 110℃ for 30 seconds, oiled, and wound to obtain graphene composite polyolefin elastic fibers. S3. Graphene composite polyolefin elastic fibers are woven on a single-sided weft knitting machine to form a weft-knitted double-sided greige fabric. The greige fabric is then sent to a heat-setting machine for heat setting treatment at a temperature of 200℃ and a speed of 25m / min. After setting, the fabric is ultrasonically cleaned twice with deionized water for 10 minutes each time to remove surface dust and oil. It is then dried with hot air circulation to obtain graphene composite fiber elastic fabric. S4. The graphene composite fiber elastic fabric is laid flat on a glove forming machine, cut using a medical glove mold, and heat-sealed to obtain a glove blank. The glove blank is placed on a light inspection table and inspected one by one with light. Defective products with pinholes, poor heat sealing, or damage are removed. Qualified products are sent to an ethylene oxide sterilization cabinet. After sterilization, they are vacuum-packed to obtain a graphene composite fiber medical elastic fabric glove.

[0038] Example 2: A specific preparation method for a graphene composite fiber medical elastic fabric glove, comprising the following steps: S1. 750g of medical-grade ethylene-octene polyolefin elastomer, 200g of branched polyolefin, 30g of graphene-modified branched polyolefin prepared according to Preparation Example 2, 3g of antioxidant (a mixture of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1) and 2g of zinc stearate were added to a high-speed mixer and mixed at 1500r / min for 8min at room temperature to obtain a premix. The premix was then added to a twin-screw extruder, and the temperatures were set as follows: Zone 1 110℃, Zone 2 130℃, Zone 3 150℃, Zone 4 180℃, Zone 5 175℃, Die head temperature 175℃, and Screw speed 160r / min. The extruded material was then water-cooled, air-dried, pelletized, and dried to obtain composite granules. S2. The composite granules are added to a melt spinning machine and melt-extruded through a spinneret with 36 holes and a single hole diameter of 0.25-0.3 mm. The extruded filaments are cooled and shaped by side blowing. The cooled filaments are introduced into a drawing heat box through guide rollers for two-stage hot drawing with a total draw ratio of 5 times. The first-stage drawing temperature is 80℃ and the second-stage drawing temperature is 100℃. The drawn filaments are heat-set at 110℃ for 30 seconds, oiled, and then wound to obtain graphene composite polyolefin elastic fibers. S3. Graphene composite polyolefin elastic fibers are woven on a single-sided weft knitting machine to form a weft-knitted double-sided greige fabric. The greige fabric is then sent to a heat-setting machine for heat setting treatment at a temperature of 105℃ and a speed of 20m / min. After setting, the fabric is ultrasonically cleaned twice with deionized water for 10 minutes each time to remove surface dust and oil. It is then dried with hot air circulation to obtain graphene composite fiber elastic fabric. S4. The graphene composite fiber elastic fabric is laid flat on a glove forming machine, cut using a medical glove mold, and heat-sealed to obtain a glove blank. The glove blank is placed on a light inspection table and inspected one by one with light. Defective products with pinholes, poor heat sealing, or damage are removed. Qualified products are sent to an ethylene oxide sterilization cabinet. After sterilization, they are vacuum-packed to obtain a graphene composite fiber medical elastic fabric glove.

[0039] Example 3: A specific preparation method for a graphene composite fiber medical elastic fabric glove, comprising the following steps: S1. 850g of medical-grade ethylene-octene polyolefin elastomer, 300g of branched polyolefin, 60g of graphene-modified branched polyolefin prepared according to Preparation Example 3, 5g of antioxidant (a mixture of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1) and 3g of zinc stearate were added to a high-speed mixer and mixed at 2000r / min for 10min at room temperature to obtain a premix. The premix was then added to a twin-screw extruder, and the temperatures were set as follows: Zone 1 120℃, Zone 2 140℃, Zone 3 160℃, Zone 4 190℃, Zone 5 180℃, Die head temperature 180℃, and screw speed 200r / min. The extruded material was then water-cooled, air-dried, pelletized, and dried to obtain composite granules. S2. The composite granules are added to a melt spinning machine and melt-extruded through a spinneret with 48 holes and a single hole diameter of 0.25-0.3 mm. The extruded filaments are cooled and shaped by side blowing. The cooled filaments are introduced into a drawing heat box through guide rollers for two-stage hot drawing with a total draw ratio of 6 times. The first-stage drawing temperature is 90℃ and the second-stage drawing temperature is 110℃. The drawn filaments are heat-set at 110℃ for 30 seconds, oiled, and then wound to obtain graphene composite polyolefin elastic fibers. S3. Graphene composite polyolefin elastic fibers are woven on a single-sided weft knitting machine to form a weft-knitted double-sided greige fabric. The greige fabric is then sent to a heat-setting machine for heat setting treatment at a temperature of 110℃ and a speed of 25m / min. After setting, the fabric is ultrasonically cleaned twice with deionized water for 10 minutes each time to remove surface dust and oil. It is then dried with hot air circulation to obtain graphene composite fiber elastic fabric. S4. The graphene composite fiber elastic fabric is laid flat on a glove forming machine, cut using a medical glove mold, and heat-sealed to obtain a glove blank. The glove blank is placed on a light inspection table and inspected one by one with light. Defective products with pinholes, poor heat sealing, or damage are removed. Qualified products are sent to an ethylene oxide sterilization cabinet. After sterilization, they are vacuum-packed to obtain a graphene composite fiber medical elastic fabric glove.

[0040] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that the graphene-modified branched polyolefin prepared according to Preparation Example 2 is replaced with the graphene-modified branched polyolefin prepared according to Comparative Preparation Example 1.

[0041] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that the graphene-modified branched polyolefin prepared according to Preparation Example 2 is replaced with the graphene-modified branched polyolefin prepared according to Comparative Preparation Example 2.

[0042] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that the graphene-modified branched polyolefin prepared according to Preparation Example 2 is replaced with the graphene-modified branched polyolefin prepared according to Comparative Preparation Example 3.

[0043] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that the graphene-modified branched polyolefin prepared according to Example 2 was replaced with a mixture of equal mass of unmodified graphene oxide and medical-grade polyethylene wax (molecular weight 5000), in which the weight ratio of graphene oxide to polyethylene wax in the mixture was 1:10.

[0044] Comparative Example 5: The difference between Comparative Example 5 and Example 2 is that no branched polyolefin is added, and the missing weight parts are made up with an equal mass of medical-grade ethylene-octene polyolefin elastomer.

[0045] Performance testing: The graphene composite fiber medical elastic fabric gloves prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to full performance tests according to the corresponding national / industry standards. Specifically, the tensile strength, elongation at break, elastic recovery at a given elongation, and permanent deformation of the gloves were tested according to GB / T 3923.1-2013 "Textiles - Tensile Properties - Part 1: Strip Method" and FZ / T 70006-2004 "Test Method for Tensile Elastic Recovery of Knitted Fabrics"; the tear strength and puncture strength of the gloves were tested according to GB 10213-2006 "Disposable Medical Rubber Examination Gloves" and ASTM F1342-19 "Standard Test Method for Puncture Resistance of Protective Clothing Materials"; and the performance of the gloves was tested according to GB 19082-2009 "Technical Requirements for Disposable Medical Protective Clothing" and ASTM F1342-19 "Standard Test Method for Puncture Resistance of Protective Clothing Materials". F1671-07, "Standard Test Method for Determining the Resistance of Protective Clothing Materials to Blood-borne Pathogen Penetration Using Phi-X174 Phage Penetration as a Test System," tests the blocking rate of Escherichia coli phage MS2 against gloves under normal and 30% constant stretch conditions; tests the antibacterial rate of the fabric against Escherichia coli and Staphylococcus aureus according to GB / T 20944.3-2008, "Evaluation of Antimicrobial Properties of Textiles - Part 3: Shaking Method"; tests the surface resistivity of gloves according to GB / T 22042-2008, "Test Method for Surface Resistivity of Clothing for Antistatic Properties"; tests the relative cell proliferation rate and sensitization rate of gloves according to GB / T 16886.5-2017, "Biological Evaluation of Medical Devices - Part 5: In Vitro Cytotoxicity Tests," and GB / T 16886.10-2017, "Biological Evaluation of Medical Devices - Part 10: Irritation and Skin Sensitization Tests"; and tests the antimicrobial rate of gloves according to GB / T 20944.3-2008, "Evaluation of Antimicrobial Properties of Textiles - Part 3: Shaking Method." According to 14233.1-2008 "Test Methods for Medical Infusion, Transfusion and Injection Equipment - Part 1: Chemical Analysis Methods", inductively coupled plasma optical emission spectrometry (ICP-OES) was used to test the residual amounts of nickel and aluminum heavy metals in finished gloves. All tests were performed in triplicate, and the average value of the test results was taken. The experimental results are shown in Table 1.

[0046] Table 1 Performance Test Results Data Analysis: As can be seen from the experimental data in Table 1, the graphene composite fiber medical elastic fabric gloves prepared by the technical solution of the present invention in Examples 1-3 all showed excellent performance in tests of mechanical strength, elastic recovery, protective barrier, functional characteristics and biosafety. Among them, Example 2 had the best overall performance and could meet the stringent requirements of protective safety, wearing comfort and use stability in medical scenarios such as operating rooms and laboratories.

[0047] From the perspective of mechanical properties and elastic recovery, Example 2 utilizes medical-grade ethylene-octene polyolefin elastomer (POE), which possesses high elasticity and low hardness. Its octene mass fraction is within the optimal range of 20%-35%, ensuring both the softness and fit of the fabric while providing a basic elastic framework. The accompanying metallocene-catalyzed long-chain branched polyethylene (mPE), with a branching degree ≥0.3 and a melt flow rate highly matched to POE, forms a dense interpenetrating entanglement network with the POE molecular chains, significantly improving melt strength and molecular chain slip resistance, effectively suppressing irreversible deformation during stretching. Furthermore... The key feature is that the graphene-modified branched polyolefin used in Example 2 has highly branched polyolefin chains that can firmly anchor the graphene sheets through amide bonds to prevent agglomeration, and can also form tight molecular entanglements with the POE / mPE matrix, so that the two-dimensional reinforcement effect of graphene can be fully utilized. Combined with two-stage thermal stretching and heat setting processes, a uniform and refined microcrystalline structure is formed inside the fiber, the molecular chain arrangement is more regular, and the stress transmission is more efficient. Ultimately, high strength, high elongation at break and high resilience are achieved, and the permanent deformation rate is controlled at an extremely low level, solving the industry pain points of elasticity decay and loose wearing of traditional polyolefin gloves.

[0048] Regarding protective barrier performance, Example 2 constructed a dual barrier system of "static density - dynamic stability," where the graphene dispersion state in the fabric is adapted to the matrix structure: Under normal conditions, the covalently grafted graphene sheets achieve nanoscale monodispersion in the fabric, requiring pathogens and chemicals to bypass the graphene sheets for penetration, significantly extending the penetration path and thus achieving an extremely high normal barrier rate; while under dynamic wearing conditions of 30% constant stretch, the long branches of branched polyethylene in Example 2 and the branched polyolefin chains grafted onto the graphene surface form an "elastic constraint network." When stretched, the branches extend synchronously like elastic bands, causing the graphene sheets to align parallel and oriented along the stretching direction. This not only does not destroy the integrity of the barrier channels but also makes the channels more regular and dense, completely avoiding the precipitous drop in barrier rate caused by graphene sheet slippage and aggregation in existing technologies, ensuring continuous protective effects during wear.

[0049] The excellent antibacterial and antistatic properties of Example 2 are noteworthy. Regarding antibacterial properties, the physical antibacterial effect of reduced graphene oxide (rGO) depends on the full exposure and uniform distribution of its sheets. The 1.5-hour polymerization time in Example 2 ensures the grafted polyolefin chain length is moderate, avoiding both aggregation caused by short chains failing to completely cover the graphene and obscuring antibacterial sites due to excessive encapsulation of graphene by long chains. The graphene sheets are uniformly distributed in the fabric, and their sharp edges can effectively cut microbial cell membranes and disrupt microbial metabolic processes, achieving highly efficient and broad-spectrum antibacterial properties. Regarding antistatic properties, the conductivity of graphene depends on the formation of continuous conductive pathways. The nanoscale monodisperse state of the graphene in Example 2 allows it to construct a continuous and dense conductive network within the fabric, quickly dissipating static charges generated on the glove surface due to friction during wear, with a surface resistance of 10 ohms. 8 The optimal range for medical applications is Ω, which avoids the accumulation of static electricity due to excessively high resistance (avoiding dust adsorption and interference with precision medical instruments) and the formation of conductive paths due to excessively low resistance (eliminating the risk of electric shock). This effect relies entirely on the dispersion stability of graphene brought about by covalent grafting modification, rather than being achieved by simple physical mixing.

[0050] Example 2 achieved stringent standards for biocompatibility and heavy metal residue control. This is likely because the graphene-modified branched polyolefin used in its preparation process employed a two-step Soxhlet extraction process, creating a dual purification barrier. The anhydrous ethanol / deionized water mixture efficiently removed residual metal ions from the catalyst and polar impurities such as hydrolysis products of the co-catalyst, while chromatographically pure hexane thoroughly removed ungrafted free polyolefin and small molecule additives. Ultimately, the nickel and aluminum heavy metal residues in the finished gloves were reduced to below medical limits. Furthermore, Example 2 did not add any small molecule dispersants, coupling agents, or antibacterial agents; functional enhancement was achieved solely through covalent grafting modification of graphene. This avoided the risk of cytotoxicity and skin sensitization caused by small molecule precipitation from the source. Combined with the excellent biocompatibility of medical-grade POE and branched PE, this resulted in a dual safety guarantee of high relative cell proliferation rate and zero sensitization rate, fully complying with the requirements of the GB / T 16886 series of medical device biological evaluation standards.

[0051] The reason why the comparative examples could not reach the performance level of Example 2 is that they deviated from the core technology of "covalent anchoring-in-situ polymerization-synergistic modification" of this invention: Comparative Example 1 omitted the oxy-chloromethcathinone oxidation step, and the catalyst only adhered to the graphene surface through physical adsorption, lacking stable amide bond anchoring. During polymerization, active centers were easily lost, leading to severe graphene sheet aggregation. This not only failed to form effective mechanical reinforcement and barrier channels but also became stress concentration points, reducing the material's mechanical properties. Comparative Example 2 omitted the catalyst terminal amino modification step, resulting in no effective grafting sites for the catalyst. Its binding force with graphene was weaker, and the aggregation phenomenon was more significant than in Comparative Example 1. Furthermore, the unanchored catalyst was difficult to completely remove through purification processes, leading to increased heavy metal residues and simultaneous deterioration of biocompatibility and functional performance. Comparative Example 3 used silane coupling agent modification + melt blending... The existing technology can only achieve weak interfacial bonding between graphene and the matrix, failing to form a continuous molecular entanglement network. Graphene sheets are prone to slippage during stretching, exhibiting significant shortcomings in dynamic barrier properties and mechanical strength, making it difficult to meet the needs of high-end medical applications. Comparative Example 4 uses a physical blending scheme of unmodified graphene oxide and polyethylene wax. Due to the strong π-π stacking effect, graphene forms micron-sized aggregates, which not only fail to exert its functional properties but also disrupt the continuous structure of the matrix. Simultaneously, polyethylene wax is prone to migration and precipitation, causing cytotoxicity and skin sensitization risks. Comparative Example 5, lacking the addition of long-chain branched polyethylene, lacks the core component for constructing a dense molecular entanglement network. Insufficient melt strength leads to poor spinnability, uneven internal crystal structure of the fiber, and a significant decrease in mechanical properties and elastic recovery. Furthermore, it cannot effectively constrain the graphene sheets, and the barrier channels are easily destroyed during stretching. Overall, its performance is inferior to that of Example 2.

[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A graphene composite fiber medical elastic fabric glove, characterized in that, It includes the following components by weight: medical-grade ethylene-α-olefin polyolefin elastomer: 65-85 parts, branched polyethylene: 10-30 parts, graphene-modified branched polyolefin: 0.3-6 parts, antioxidant: 0.1-0.5 parts, lubricant: 0.1-0.3 parts; The preparation method of the graphene-modified branched polyolefin is as follows: (1) Under nitrogen protection, the α-diimine nickel catalyst was dissolved in anhydrous dichloromethane to prepare a solution with a concentration of 0.3-0.5 mol / L. The solution was cooled to 0°C in an ice bath, and phosphorus tribromide was added. The temperature of the system was controlled not to exceed 5°C during the addition. After the addition was completed, the solution was brought back to room temperature and stirred for 3-4 hours. After the reaction was completed, excess phosphorus tribromide was quenched by adding ice water in an ice bath. The organic phase was separated and washed with saturated sodium bicarbonate solution until neutral. The organic phase was washed twice with saturated brine, dried with anhydrous sodium sulfate, filtered, concentrated under reduced pressure to 1 / 10 of the original volume, and precipitated by adding anhydrous n-hexane. After filtration, the precipitate was recrystallized twice with anhydrous n-hexane and dried under vacuum to obtain the benzyl bromide-substituted α-diimine nickel catalyst. (2) Under nitrogen protection, benzyl bromide-substituted α-diimide nickel catalyst was added to anhydrous DMF, potassium phthalimide was added, the temperature was raised to 50-60℃, the reaction was stirred for 6-8h, after the reaction was completed, the mixture was cooled to room temperature, filtered, deionized water was added to the filtrate to precipitate, the mixture was filtered again, and the mixture was washed 3 times alternately with deionized water and anhydrous ethanol, and dried to obtain the phthalimide-protected catalyst intermediate; (3) Add the phthalimide-protected catalyst intermediate to anhydrous ethanol, add hydrazine hydrate, heat to 40-50℃, stir for 1-3h, filter while hot to remove phthalimide hydrazine precipitate, concentrate the filtrate under reduced pressure to 1 / 5 of the original volume, add anhydrous n-hexane to precipitate, filter and dry to obtain terminal amino α-diimide nickel catalyst; (4) Disperse monolayer graphene oxide in anhydrous DMF, sonicate for 30-60 min to obtain a graphene oxide dispersion with a concentration of 1-3 mg / ml, add thionyl chloride / DMF mixture to the dispersion, heat to 65-75℃ under nitrogen protection, reflux for 12-24 h, filter, wash 3 times with anhydrous tetrahydrofuran, and dry to obtain acyl-chlorinated graphene oxide. (5) Disperse acyl chloride graphene oxide in anhydrous toluene, add terminal amino α-diimine nickel catalyst and anhydrous triethylamine under nitrogen protection, heat to 40-60℃, stir for 6-12h, collect the precipitate by centrifugation after the reaction, wash the precipitate with ethanol 3-5 times, and dry to obtain catalyst covalently anchored graphene oxide. (6) Under nitrogen protection, the covalently anchored graphene oxide was placed in a high-pressure reactor, anhydrous toluene was added and stirred to disperse it evenly, methylaluminoxane was added, and high-purity ethylene gas was continuously introduced to maintain the system pressure at 0.5-1.5 MPa. The temperature was raised to 20-60℃ and stirred for 0.8-2.5 h for polymerization. After the reaction was completed, 5% by volume of acidified methanol was added to terminate the reaction. After filtration, the crude product was obtained. (7) The crude product was loaded into a cellulose extraction sleeve with a pore size of 220 nm and placed in a Soxhlet extractor. Anhydrous ethanol / deionized water mixture was used as the extraction solvent and the product was heated and refluxed under nitrogen protection for 12-24 h to complete the first extraction. The product after the first extraction was taken out, dried under vacuum at 30 °C, and then loaded back into the cellulose extraction sleeve and placed in a Soxhlet extractor. Chromatographically pure hexane was used as the extraction solvent and the product was heated and refluxed under nitrogen protection for 24-48 h to obtain graphene-modified branched polyolefin.

2. The graphene composite fiber medical elastic fabric glove according to claim 1, characterized in that, The medical-grade ethylene-α-olefin polyolefin elastomer is an ethylene-octene copolymer with an octene mass fraction of 20%-35%, a melt flow rate of 0.5-5 g / 10 min at 190°C and 2.16 kg, and a Shore hardness of 50-70 A. The branched polyethylene is a long-chain branched polyethylene prepared by metallocene catalysis, with a melt flow rate of 0.3-3 g / 10 min at 190°C and 2.16 kg, and a density of 0.865-0.890 g / cm³. 3 The degree of branching is ≥0.3; the antioxidant refers to a mixture of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1; the lubricant refers to any one of sodium stearate, zinc stearate, and potassium stearate.

3. The graphene composite fiber medical elastic fabric glove according to claim 1, characterized in that, The α-diimine nickel catalyst in (1) has the following chemical structure: The molar ratio of the α-diimine nickel catalyst to phosphorus tribromide is 1:0.7-0.

8.

4. The graphene composite fiber medical elastic fabric glove according to claim 1, characterized in that, In (2), the molar ratio of benzyl bromide-substituted α-diimide nickel catalyst and potassium phthalimide is 1:2.1-2.4; the weight ratio of benzyl bromide-substituted α-diimide nickel catalyst and anhydrous DMF is 1:10-20.

5. The graphene composite fiber medical elastic fabric glove according to claim 1, characterized in that, In (3), the molar ratio of the phthalimide-protected catalyst intermediate to hydrazine hydrate is 1:2.1-2.4; the weight ratio of the phthalimide-protected catalyst intermediate to anhydrous ethanol is 1:10-20.

6. The graphene composite fiber medical elastic fabric glove according to claim 1, characterized in that, In (4), the weight ratio of monolayer graphene oxide and thionyl chloride is 1:20-30; the volume fraction of thionyl chloride in the thionyl chloride / DMF mixture is 90%.

7. The graphene composite fiber medical elastic fabric glove according to claim 1, characterized in that, In (5), the acyl chloride graphene oxide, anhydrous toluene, terminal amino α-diimide nickel catalyst and anhydrous triethylamine are in a weight ratio of 1:20-40:0.08-0.25:0.05-0.

1.

8. The graphene composite fiber medical elastic fabric glove according to claim 1, characterized in that, The covalently anchored graphene oxide, anhydrous toluene, and methylaluminoxane in (6) are in a weight ratio of 1:200-500:2-6.

9. The graphene composite fiber medical elastic fabric glove according to claim 1, characterized in that, In the anhydrous ethanol / deionized water mixture in (7), the volume ratio of anhydrous ethanol to deionized water is 4:

1.

10. The method for preparing graphene composite fiber medical elastic fabric gloves according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Add medical-grade ethylene-octene polyolefin elastomer, branched polyolefin, graphene-modified branched polyolefin, antioxidant, and lubricant to a high-speed mixer and mix at 1000-2000 r / min for 5-10 min at room temperature to obtain a premix. Add the premix to a twin-screw extruder and set the temperatures as follows: Zone 1 100-120℃, Zone 2 120-140℃, Zone 3 140-160℃, Zone 4 170-190℃, Zone 5 170-180℃, die head temperature 170-180℃, and screw speed 120-200 r / min. After extrusion, the material is cooled by water, air-dried, pelletized, and dried to obtain composite granules. S2. The composite granules are added to a melt spinning machine and melt-extruded through a spinneret with 24-48 holes and a single hole diameter of 0.25-0.3 mm. The extruded filaments are cooled and shaped by side blowing. The cooled filaments are introduced into a drawing heat box through guide rollers for two-stage hot drawing. The total draw ratio is 3-6 times. The first-stage drawing temperature is 70-90℃ and the second-stage drawing temperature is 90-110℃. The drawn filaments are heat-set at 110℃ for 30 seconds, oiled, and then wound to obtain graphene composite polyolefin elastic fibers. S3. Graphene composite polyolefin elastic fibers are woven on a single-sided weft knitting machine to form a weft-knitted double-sided greige fabric. The greige fabric is then sent to a heat-setting machine for heat setting treatment. The setting temperature is 100-110℃ and the setting speed is 15-25m / min. After setting, the fabric is ultrasonically cleaned twice with deionized water for 10 minutes each time to remove surface dust and oil. It is then dried with hot air circulation to obtain graphene composite fiber elastic fabric. S4. The graphene composite fiber elastic fabric is laid flat on a glove forming machine, cut using a medical glove mold, and heat-sealed to obtain a glove blank. The glove blank is placed on a light inspection table and inspected one by one with light. Defective products with pinholes, poor heat sealing, or damage are removed. Qualified products are sent to an ethylene oxide sterilization cabinet. After sterilization, they are vacuum-packed to obtain a graphene composite fiber medical elastic fabric glove.

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