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CN-121991477-A - Degradable antibacterial medical needle tube plastic and preparation process thereof

CN121991477ACN 121991477 ACN121991477 ACN 121991477ACN-121991477-A

Abstract

The invention discloses a degradable antibacterial medical needle tube plastic and a preparation process thereof, and belongs to the technical field of medical polymer materials. The plastic consists of ternary random copolyester, a nucleating agent and a lubricant, wherein the ternary random copolyester is prepared by polycondensation of three monomers of lactic acid, 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) -3-hydroxypropionic acid and N- (2-carboxyl-2-hydroxyethyl) -N, N-dimethyl dodecane-1-ammonium chloride. According to the invention, the hindered phenol irradiation-resistant unit and the long-chain alkyl quaternary ammonium salt antibacterial unit are embedded into the polylactic acid main chain in a covalent bond manner, so that the problem that a physically blended small molecule auxiliary agent is easy to migrate and separate out is solved from a molecular level, the material is endowed with high-efficiency and stable irradiation resistance and broad-spectrum antibacterial performance synchronously, and the material is completely biodegradable, has excellent comprehensive performance and meets the industrial production requirements of medical needle tubes.

Inventors

  • CAI JIEXIANG

Assignees

  • 湖南斯托德医疗器械有限公司

Dates

Publication Date
20260508
Application Date
20260409

Claims (10)

  1. 1. The degradable antibacterial medical needle tube plastic is characterized by comprising the following raw materials, by weight, 100 parts of a plastic matrix, 0.1-0.3 part of a nucleating agent and 0.1-0.2 part of a lubricant; The plastic matrix is ternary random copolyester, wherein the repeating units of the ternary random copolyester are formed by randomly connecting lactic acid repeating units, hindered phenol type radiation-resistant repeating units and quaternary ammonium salt type antibacterial repeating units through ester bonds, and the molar ratio of each unit is 85-97mol% of lactic acid repeating units, 1-10mol% of hindered phenol type radiation-resistant repeating units and 2-5mol% of quaternary ammonium salt type antibacterial repeating units based on the total molar amount of all the repeating units; the lactic acid repeating unit is derived from a lactic acid monomer; the hindered phenol type radiation-resistant repeating unit is from a 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) -3-hydroxy propionic acid monomer, and the chemical structural formula is as follows: ; the quaternary ammonium salt type antibacterial repeating unit is from an N- (2-carboxyl-2-hydroxyethyl) -N, N-dimethyl dodecane-1-ammonium chloride monomer, and the chemical structural formula is as follows: 。
  2. 2. The degradable antibacterial medical needle tube plastic according to claim 1, wherein the nucleating agent is one of nano talcum powder or 1,3:2, 4-di (3, 4-dimethylbenzylidene) -D-sorbitol, and the lubricant is one of calcium stearate or ethylene bis stearamide.
  3. 3. The degradable antibacterial medical needle tube plastic according to claim 1, wherein the preparation method of the 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) -3-hydroxypropionic acid comprises the following steps: S101, under the condition of nitrogen protection and no water or oxygen, zinc powder and anhydrous tetrahydrofuran are added into a dry reaction kettle, the temperature is controlled to be 0-5 ℃ under stirring, 5-10% of the total mass of ethyl bromoacetate is added, stirring is kept, 3, 5-di-tert-butyl-4-hydroxybenzaldehyde and the rest ethyl bromoacetate are prepared into anhydrous tetrahydrofuran raw material solution with the concentration of 30-40wt%, after the reaction system has spontaneous heating confirmation reaction initiation, the temperature is controlled to be 0-5 ℃, the prepared anhydrous tetrahydrofuran raw material solution is dripped into the reaction kettle, the temperature is controlled to be not more than 5 ℃ in the dripping process, the temperature is raised to be 50-60 ℃ after the dripping is finished, and the temperature is kept and stirring is carried out for 4-6 hours; S102, after the reaction is finished, cooling to room temperature, filtering, adding a saturated ammonium chloride solution into the filtrate to quench the reaction, extracting the reaction for 3 times by using ethyl acetate, merging the organic phases, washing the organic phases by using saturated saline water for 3 times, adding anhydrous sodium sulfate into the organic phases to dry, filtering, removing the solvent from the filtrate by distillation under reduced pressure to obtain an intermediate A, adding the intermediate A into an ethanol/water mixed solution, stirring and dissolving the intermediate A, adding lithium hydroxide, heating to 40-50 ℃, keeping the temperature and stirring for 3-4 hours, removing the ethanol in the system by distillation under reduced pressure, regulating the pH of the residual water solution to be acidic by using dilute hydrochloric acid until the system has solid precipitation, filtering, washing a filter cake by using deionized water for 3 times, and recrystallizing the dried filter cake by using a petroleum ether/ethyl acetate mixed solution to obtain 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) -3-hydroxypropionic acid.
  4. 4. The degradable antibacterial medical needle tube plastic according to claim 3, wherein the molar ratio of 3, 5-di-tert-butyl-4-hydroxybenzaldehyde, ethyl bromoacetate and zinc powder in S101 is 1:1.1-1.3:1.2-1.5, and the weight ratio of zinc powder to anhydrous tetrahydrofuran is 1:20-30.
  5. 5. The degradable antibacterial medical needle tube plastic according to claim 3, wherein the weight ratio of the intermediate A to the ethanol/water mixed solution to the lithium hydroxide is 1:8-10:0.08-0.12, the volume ratio of the ethanol to the water in the ethanol/water mixed solution is 1:1, the volume ratio of the petroleum ether to the ethyl acetate in the petroleum ether/ethyl acetate mixed solution is 2:3, and the concentration of the dilute hydrochloric acid is 0.1-3mol/L.
  6. 6. The degradable antibacterial medical needle tube plastic according to claim 1, wherein the preparation method of the N- (2-carboxyl-2-hydroxyethyl) -N, N-dimethyl dodecane-1-ammonium chloride comprises the following steps: s201, adding dodecyl dimethyl tertiary amine and 3-chloro-2-hydroxy methyl propionate into absolute ethyl alcohol under the protection of nitrogen, heating to 60-70 ℃ under stirring, and reacting for 6-10h; S202, after the reaction is finished, distilling under reduced pressure to remove a solvent to obtain a crude product of the quaternary ammonium methyl ester, adding the crude product of the quaternary ammonium methyl ester into an ethanol/water mixed solution, stirring and dissolving, adding lithium hydroxide, heating to 40-50 ℃, carrying out heat preservation and stirring reaction for 3-4h, distilling under reduced pressure to remove ethanol in a system, regulating pH of the residual water solution to 3.0-3.5 by dilute hydrochloric acid, distilling under reduced pressure again to remove water in the system, adding the residual product into ethanol, heating to 60-70 ℃, stirring for 10-20min, filtering while the solution is hot, adding acetone into the filtrate until solid is separated out, cooling to 0-5 ℃, standing for 1-2h, filtering, and recrystallizing a filter cake by using the ethanol/acetone mixed solution to obtain N- (2-carboxyl-2-hydroxyethyl) -N, N-dimethyl dodecane-1-ammonium chloride.
  7. 7. The degradable antibacterial medical needle tube plastic according to claim 6, wherein the molar ratio of the dodecyl dimethyl tertiary amine to the 3-chloro-2-hydroxy methyl propionate in the S201 is 1:1.05-1.3, and the weight ratio of the dodecyl dimethyl tertiary amine to the absolute ethyl alcohol is 1:5-10.
  8. 8. The degradable antibacterial medical needle tube plastic according to claim 6, wherein the weight ratio of the crude quaternary ammonium salt methyl ester to the ethanol/water mixed solution, the lithium hydroxide to the ethanol in the S202 is 1:8-12:0.08-0.12:5-10, the volume ratio of the ethanol to the water in the ethanol/water mixed solution is 1:1, the volume ratio of the ethanol to the acetone in the ethanol/acetone mixed solution is 3:1, and the concentration of the dilute hydrochloric acid is 0.1-3mol/L.
  9. 9. The process for preparing the degradable antibacterial medical needle tube plastic according to any one of claims 1 to 8, which is characterized by comprising the following steps: (1) Continuously introducing nitrogen into a reaction kettle with a water separator for protection, adding a lactic acid repeating unit, a hindered phenol type radiation-resistant repeating unit, a quaternary ammonium salt type antibacterial repeating unit and a catalyst, heating to 140-160 ℃ under stirring, reacting for 3-6h, removing water generated by the reaction through the water separator and nitrogen flow during the reaction, heating to 170-190 ℃, continuously reducing the pressure to be less than or equal to 50Pa, reacting for 8-12h, discharging, cooling, and crushing into particles to obtain ternary random copolyester; (2) Adding the ternary random copolyester, the nucleating agent and the lubricant into a high-speed mixer, mixing for 3-5min to be uniform, adding the mixture into a double-screw extruder under the protection of nitrogen, setting the temperature of a first region to be 155-165 ℃, the temperature of a second region to be 165-175 ℃, the temperature of a third region to be 175-185 ℃, the temperature of a fourth region to be 175-185 ℃, the temperature of a fifth region to be 175-180 ℃, the temperature of a die head to be 170-180 ℃, the length-diameter ratio of the screw to be 40-48:1, the rotating speed of the screw to be 180-220r/min, opening a vacuum port in the whole process in the extrusion process, and performing underwater granulating after melt extrusion and drying to obtain the degradable antibacterial medical needle tube plastic.
  10. 10. The preparation process of the degradable antibacterial medical needle tube plastic according to claim 9, wherein the catalyst in the step (1) is stannous octoate, and the addition amount of the catalyst is 0.3-0.8% of the total mass of lactic acid repeating units, hindered phenol type radiation-resistant repeating units and quaternary ammonium salt type antibacterial repeating units.

Description

Degradable antibacterial medical needle tube plastic and preparation process thereof Technical Field The invention relates to the technical field of medical polymer materials, in particular to a degradable antibacterial medical needle tube plastic and a preparation process thereof. Background The disposable medical injector is one of the largest disposable consumables in the scenes of clinical diagnosis and treatment, vaccination and the like, the annual consumption of the disposable injector exceeds one hundred billion, the traditional medical needle tube is mostly prepared by adopting non-degradable petroleum-based plastics such as polypropylene (PP) and the like, the materials are difficult to degrade in natural environment, a large amount of medical plastic waste can be generated after the medical injector is used, serious white pollution and ecological environment burden are caused, and meanwhile, a certain lifting space exists for the biosafety of the petroleum-based material. Polylactic acid (PLA) is used as a completely biodegradable bio-based polymer material, is synthesized by taking renewable plant resources as raw materials, can be completely degraded into carbon dioxide and water under natural environment and industrial composting conditions, has excellent biocompatibility, good mechanical rigidity and thermoplastic processability, is an ideal material for replacing the traditional non-degradable medical plastic to prepare environment-friendly medical consumables, and has extremely high application value and industrialization prospect in the field of disposable medical needle tubes. The large-scale application of polylactic acid materials in the field of medical needle tubes still faces two major technical bottlenecks. On one hand, medical consumables must undergo strict sterilization treatment before clinical use, gamma-ray irradiation sterilization is the most common sterilization mode of medical consumables, the conventional sterilization dosage is 25kGy, the polylactic acid molecular chain is extremely sensitive to irradiation, a large number of active free radicals can be generated in the irradiation process, norris type alpha-cleavage and random chain scission reaction of a main chain are initiated, the sudden drop of the molecular weight, the great attenuation of the mechanical property and the yellowing embrittlement of products are finally caused, the mechanical use requirement of medical syringes cannot be met, and the medical consumables are the most core obstacle for limiting the application of polylactic acid in the field of medical irradiation sterilization consumables. On the other hand, the medical needle tube is used as an invasive consumable material directly contacting human tissues and liquid medicine, and needs to have excellent antibacterial performance so as to avoid bacterial breeding and cross infection in the clinical use process, but the pure polylactic acid has no antibacterial activity and cannot meet the antibacterial protection requirement of medical scenes, and the material needs to be endowed with stable and safe antibacterial functions through modification. Aiming at the pain point, the most commonly used solution in the prior art is physical blending modification, namely, the irradiation resistance of the material is improved by physically blending small molecular hindered phenol antioxidants in a polylactic acid matrix, and the antibacterial agent such as nano silver, small molecular quaternary ammonium salt and the like is blended to endow the material with antibacterial function. However, the existing physical blending modification scheme has inherent defects which cannot be overcome, and the comprehensive performance and safety requirements of the medical needle tube material are difficult to meet. Firstly, the compatibility of a physically blended small-molecule auxiliary agent and a polylactic acid matrix is limited, migration, volatilization, precipitation and frosting are extremely easy to occur in the high-temperature processing process of double-screw extrusion and injection molding and the subsequent irradiation sterilization and long-term storage processes, so that the irradiation-resistant and antibacterial functions of the material are continuously attenuated along with time, the long-acting stable functional effect cannot be realized, and more importantly, the precipitated small-molecule auxiliary agent can bring serious cytotoxicity, hemolysis and sensitization risks, and cannot meet the strict biosafety supervision requirements of medical consumables. Secondly, the physically blended small molecular antioxidant can only exist in a polylactic acid matrix in a disperse phase form, the dispersion uniformity is limited, the in-situ and full-coverage protection of polylactic acid molecular chains cannot be realized, the main chain fracture chain reaction caused by radiation is difficult to block from the root, the obvious upper limit of the radiati