Low-resistance puncture-easy disposable isolation plug and preparation process thereof

Abstract

This invention discloses a low-resistance, easily puncturable disposable isolation plug and its preparation process, belonging to the field of isolation plug processing technology. It addresses the technical problem that the puncture and sealing performance of existing isolation plugs needs further improvement. Specifically, it comprises the following components by weight: 70-80 parts isoprene rubber, 10-15 parts modified vulcanization accelerator, 3-5 parts modified self-lubricating capsules, 2-3 parts sulfur, and 1-3 parts excipients. This invention obtains a modified vulcanization accelerator by reacting pretreated chitosan with carbon disulfide, prepares a polyurethane prepolymer using an antibacterial diol, further emulsifies it to form self-lubricating microcapsules, and modifies them with dopamine / graphene oxide. The isoprene rubber is then mixed with the modified capsules and excipients, followed by the addition of the modified vulcanization accelerator and sulfur for open mixing, curing, and vulcanization molding, resulting in a disposable isolation plug with low puncture force, low shedding, and good self-sealing properties.

Description

Technical Field

[0001] This invention relates to the field of isolation plug processing technology, specifically to a low-resistance, easily puncturable disposable isolation plug and its preparation process. Background Technology

[0002] As the medical industry continues to demand higher performance from disposable isolation plugs, low resistance and easy puncture properties, as well as good sealing performance, have become key technical indicators. Traditional rubber isolation plugs, while effectively sealing and preventing liquid leakage during use, have relatively high puncture force, especially under high-pressure environments, which can easily lead to uneven puncture and sealing failure. In recent years, with the continuous exploration of new materials and processes, low-resistance, easy-puncture isolation plugs have emerged. These plugs not only have excellent self-sealing properties but also provide good sealing effects with lower puncture force, greatly improving safety and stability during use.

[0003] Commonly used isolation plug materials are generally natural or synthetic rubber, silicone, etc., which have the advantages of good elasticity and strong plasticity, and can effectively seal. However, a single material is often difficult to meet the dual requirements of low puncture force and high sealing performance. Therefore, composite materials or surface modification treatments are often used. Common modification methods include cross-linking modification, filler reinforcement, surface coating, and the use of nanomaterials. For example, using fillers such as carbon black or silicone can enhance the wear resistance of the material, while surface coating technology can effectively reduce puncture resistance and improve the contact interface with the needle.

[0004] Currently, traditional rubber materials are prone to permanent compression deformation when subjected to pressure, and the molecular chains are difficult to fully recover, resulting in a long-term decrease in sealing performance. In addition, their mechanical strength is limited, and they are prone to forming microcracks under the concentrated stress of needle puncture, affecting structural integrity. The high molecular chain density and interfacial friction make the puncture resistance too large, and insufficient needle tip cutting can also cause chipping, affecting the purity of the medicine. Furthermore, traditional materials lack inherent antibacterial structure, and microorganisms are prone to grow on the surface, increasing the potential risk of contamination.

[0005] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a low-resistance, easily puncturable disposable isolation plug and its manufacturing process, in order to solve the technical problem that the puncture performance and sealing performance of isolation plugs in the prior art need to be further improved.

[0007] The objective of this invention can be achieved through the following technical solution: a low-resistance, easily puncturable disposable isolation plug, comprising the following components by weight: 70-80 parts isoprene rubber, 10-15 parts modified vulcanization accelerator, 3-5 parts modified self-lubricating capsule, 2-3 parts sulfur and 1-3 parts excipients.

[0008] The modified self-lubricating capsule is prepared by the following steps:

[0009] A1. Place polydimethylsiloxane, polyurethane prepolymer and dichloromethane in a reaction vessel and stir at room temperature for 15-30 min to obtain a mixed oil phase;

[0010] A2. Place deionized water and sodium lignosulfonate in a reaction vessel, stir at room temperature for 15-30 minutes, slowly add the mixed oil phase, heat the reaction vessel to 35-45℃, keep the reaction at this temperature for 2-4 hours, and then process to obtain self-lubricating capsules.

[0011] A3. Place the self-lubricating capsules and dopamine hydrochloride in a reaction vessel and stir. Add Tris buffer to adjust the pH to 8-8.5 and react at room temperature for 20-24 hours. Add graphene oxide aqueous solution dropwise and react at room temperature for 20-24 hours. Post-process to obtain the modified self-lubricating capsules.

[0012] The reaction principle for preparing modified self-lubricating capsules is as follows:

[0013] During the reaction, polydimethylsiloxane and polyurethane prepolymer are mixed in dichloromethane to form a mixed oil phase. In step A2, sodium lignosulfonate acts as an emulsifier and stabilizer, enabling the mixed oil phase to form a stable water-in-oil emulsion system in the aqueous phase. Subsequently, at 35-45℃, the active end -NCO in the polyurethane prepolymer undergoes interfacial polymerization with trace amounts of water in the aqueous phase, rapidly forming a polyurethane coating on the surface of the oil droplets. This coating encapsulates the polydimethylsiloxane to form a core-shell structured self-lubricating capsule. In step A3, dopamine undergoes auto-oxidative polymerization under alkaline conditions to form a polydopamine coating. Subsequently, it is combined with graphene oxide through π-π stacking and hydrogen bonding to construct a composite coating, achieving functional modification of the microcapsule surface and obtaining a modified self-lubricating capsule.

[0014] Furthermore, in step A1, the ratio of polydimethylsiloxane, polyurethane prepolymer, and dichloromethane is 2-4g:1-2g:25-30mL.

[0015] Furthermore, in step A2, the ratio of deionized water, sodium lignosulfonate, and mixed oil phase is 100-120mL:0.5-1.5g:28-30mL. The post-treatment steps include: after the reaction is completed, wait for the reaction system to cool to room temperature, filter, wash the filter cake with deionized water 2-4 times, transfer it to an oven at 50-60℃, dry it to constant weight, and self-lubricating capsules.

[0016] Further, in step A3, the ratio of the self-lubricating capsule, dopamine hydrochloride, and graphene oxide aqueous solution is 2-4g:0.2-0.4g:8-10mL, and the concentration of the graphene oxide aqueous solution is 2-4wt%. The post-processing steps include: after the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed 2-4 times with deionized water, transferred to an oven at 50-60℃, and dried to constant weight to obtain the modified self-lubricating capsule.

[0017] Furthermore, the polyurethane prepolymer is prepared by the following steps:

[0018] B1. Cinnamic acid, triethanolamine and p-toluenesulfonic acid are placed in a reaction vessel and stirred. The reaction vessel is heated to 175-185℃ and kept at this temperature for 6-8 hours. The antibacterial modified diol is obtained after post-treatment.

[0019] B2. Antibacterial modified diol, polyethylene glycol, dibutyltin dilaurate and toluene are placed in a reaction vessel under nitrogen atmosphere and stirred. The reaction vessel is heated to 80-90℃, toluene-2,4-diisocyanate is added, and the reaction is maintained at this temperature for 2-4 hours. The polyurethane prepolymer is then obtained after post-treatment.

[0020] The preparation reaction principle of polyurethane prepolymer is as follows:

[0021] During the reaction, cinnamic acid undergoes esterification with triethanolamine under the catalysis of p-toluenesulfonic acid to generate an antibacterial modified diol containing cinnamic groups. In step B2, the antibacterial modified diol and polyethylene glycol undergo an addition reaction with toluene-2,4-diisocyanate under the catalysis of dibutyltin dilaurate. The isocyanate groups polymerize with hydroxyl groups to form urethane bonds. By controlling the excess of toluene-2,4-diisocyanate, a polyurethane prepolymer containing active-terminal -NCO groups is generated.

[0022] Further, in step B1, the weight ratio of cinnamic acid, triethanolamine, and p-toluenesulfonic acid is 1-2:1.5-2.5:0.02-0.04. The post-processing step includes: after the reaction is completed, wait for the reaction solution to cool to room temperature, add a saturated saline solution with the same volume as the reaction solution, wash and extract 1-3 times, transfer the organic phase to a rotary evaporator at a temperature of 80-90℃, and rotary evaporate until no liquid is collected to obtain antibacterial modified diol;

[0023] Further, in step B2, the ratio of the antibacterial modified diol, polyethylene glycol, dibutyltin dilaurate, and toluene is 1-2g:4-6g:0.2-0.4g:80-100mL, and the molar amount of toluene-2,4-diisocyanate is 0.55 times the total molar amount of hydroxyl groups in the antibacterial modified diol and polyethylene glycol. The post-processing step includes: after the reaction is completed, heating the reaction vessel to 110-120℃ and distilling under reduced pressure until no liquid is collected, to obtain the polyurethane prepolymer.

[0024] Furthermore, the modified vulcanization accelerator is prepared by the following steps:

[0025] C1. Chitosan, deionized water and sodium hydroxide are placed in a reaction vessel and stirred. The reaction is carried out at room temperature for 0.5-1 h. The reaction vessel is then cooled to -5-0℃ and kept at this temperature for 4-6 h. The resulting pretreated chitosan is obtained after post-treatment.

[0026] C2. Place the pretreated chitosan and methanol in a reaction vessel and stir. Add carbon disulfide methanol solution dropwise. Stir at room temperature for 15-30 minutes. Heat the reaction vessel to 50-60℃ and keep it at that temperature for 4-6 hours. The modified vulcanization accelerator is obtained after post-treatment.

[0027] The preparation reaction principle of the modified vulcanization accelerator is as follows:

[0028] During the reaction, chitosan undergoes deacetylation under alkaline conditions and stabilizes at low temperature to form an alkaline structure. In step C2, pretreated chitosan undergoes a nucleophilic substitution reaction with carbon disulfide, and the active amino groups on chitosan react with carbon disulfide to generate dithiocarbamate structures, thus obtaining a modified vulcanization accelerator.

[0029] Further, in step C1, the ratio of chitosan, deionized water and sodium hydroxide is 10-12g:120-140mL:50-60g. The post-treatment step includes: after the reaction is completed, wait for the reaction solution to rise to room temperature, filter, wash the filter cake with deionized water 2-4 times, transfer it to an oven at 40-50℃, and dry it to constant weight to obtain pretreated chitosan.

[0030] Further, in step C2, the ratio of the pretreated chitosan, methanol, and carbon disulfide methanol solution is 13-15g:50-70mL:180-200mL, and the concentration of the carbon disulfide methanol solution is 30-35wt%. The post-treatment step includes: after the reaction is completed, the reaction solution is cooled to room temperature, filtered, the filter cake is washed with methanol 2-4 times, transferred to an oven at 40-50℃, and dried to constant weight to obtain the modified vulcanization accelerator.

[0031] The present invention also proposes a manufacturing process for a low-resistance, easily puncturable disposable isolation plug, comprising the following steps:

[0032] S1. Add isoprene rubber to a mixer at a temperature of 45-55℃ and mix for 1-3 minutes. Add modified self-lubricating capsules and auxiliary materials and mix for 3-5 minutes to obtain the compound.

[0033] S2. Add the mixed rubber to a two-roll mill, add the modified vulcanization accelerator and sulfur, cut the rubber alternately from left to right 3 times each, pass through a thin mill 10 times, cure for 10-12 hours, and mold to obtain a disposable isolation plug.

[0034] Further, in step S1, the excipients are composed of an antioxidant, a lubricant, and a plasticizer in a mass ratio of 1:2:2. The antioxidant is one or more of N-isopropyl-N'-phenyl-p-phenylenediamine, N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The lubricant is one or more of stearic acid, paraffin wax, and erucamide. The plasticizer is one or more of dioctyl phthalate, dibutyl phthalate, and diisononyl phthalate.

[0035] Furthermore, in step S2, the compression molding operation steps include: after curing, cutting the cured rubber material into slices and placing them into a mold that has been preheated to 80-100℃, transferring them to a hot press molding machine for vulcanization, setting the temperature to 150-160℃, the pressure to 15-20Mpa, and the time to 10-15min, and cooling to obtain a disposable isolation plug.

[0036] The present invention has the following beneficial effects:

[0037] 1. The modified vulcanization accelerator prepared in this invention forms a multi-site synergistic structure containing active sulfur bonds and amino groups through pretreatment of chitosan and carbon disulfide functionalization. Compared with traditional small molecule vulcanization accelerators, it has more chemical reaction sites, better dispersibility, and significantly improved interfacial affinity with the rubber matrix. Moreover, the modified vulcanization accelerator can provide a uniform and controllable cross-linking reaction during vulcanization, making the isoprene rubber network structure denser and less rigid, effectively improving the elasticity retention rate of the stopper and its stability against repeated punctures. Secondly, the active amino groups remaining in the chitosan skeleton can form a strong interfacial bond with the rubber matrix, making the accelerator highly dispersed in the rubber compound, significantly reducing the migration of the vulcanization system, avoiding the blooming problem caused by traditional accelerators, and improving the chemical stability and safety of the product. At the same time, the hydrophilic groups derived from chitosan can improve the wettability and micro-compliance of the stopper surface to a certain extent, making the material deformation at the moment of puncture easier, reducing the puncture resistance of the rubber stopper, and making the needle tip cut in more smoothly.

[0038] 2. The modified self-lubricating capsule prepared in this invention achieves synergistic optimization of self-lubrication, mechanical reinforcement, and interfacial adhesion through a three-level structural design of a silicone oil core, an antibacterial modified polyurethane prepolymer wall, and a dopamine / graphene oxide composite outer layer. First, the polydimethylsiloxane embedded in the core of the modified self-lubricating capsule can be locally released when puncture is applied, forming an instantaneous lubricating layer in the needle tip contact area, which significantly reduces the initial puncture force and continuous puncture resistance, giving the isolation plug a low-resistance and easy-to-puncture function. At the same time, the directional release of the lubricant can reduce shear damage at the needle tip and rubber interface, reduce the debris generation rate, and improve safety during medical use. Second, the capsule wall layer composed of polyurethane prepolymer has good elasticity and toughness, and acts as a flexible micro-reinforcing structure in the rubber matrix, which can improve stress distribution and enhance the tear resistance and deformation recovery ability of the isolation plug after multiple punctures.

[0039] 3. The modified self-lubricating capsule of the present invention, with its outer layer constructed of dopamine and graphene oxide, not only enhances the interfacial bonding ability of the capsule in the rubber matrix, avoiding blooming or surface failure caused by lubricant migration, but also its surface functional groups can improve the overall wear resistance and microstructure stability of the material, making the self-lubricating effect more durable. In addition, the modified self-lubricating capsule has excellent dispersibility under vulcanization conditions, without cell wall breakage or aggregation, ensuring the uniformity of lubrication function and maintaining stable puncture performance of the isolation plug in different parts. At the same time, the antibacterial modified diol is composed of cinnamic acid and triethanolamine, which has hydroxyl, ester and aromatic groups. The cinnamic acid group gives the material continuous antibacterial ability, which can significantly reduce the risk of bacterial adhesion and contamination of microcapsules and isolation plugs during storage and use. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The polydimethylsiloxane used in this invention was purchased from Xi'an Hongyao Pharmaceutical Excipients Co., Ltd. The product grade is chemically pure CP, the effective ingredient content is 99%, the molecular weight is 12500, and the appearance is a colorless and clear oily liquid.

[0042] The dopamine hydrochloride used in this invention was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., catalog number D103111, with a purity of 98%.

[0043] The Tris buffer used in this invention was purchased from Shanghai Yueteng Biotechnology Co., Ltd., with a pH of 7.0-9.0;

[0044] The polyethylene glycol used in this invention was purchased from Shaanxi Changji Fu Biotechnology Co., Ltd., and the standard implemented is the pharmacopoeia, with a molecular weight of 400.

[0045] The chitosan used in this invention was purchased from Shaanxi Panlong Yihai Pharmaceutical Co., Ltd., and the standard implemented is the CP Pharmacopoeia standard;

[0046] The isoprene rubber used in this invention was purchased from Hubei Greet Biomedical Technology Co., Ltd., with a purity of 99%, model number GREAT0047, and product name polyisoprene.

[0047] Example 1

[0048] This embodiment provides a preparation process for a modified vulcanization accelerator, including the following steps:

[0049] Step I: Preparation of pretreated chitosan

[0050] Weigh out 100g of chitosan, 1200mL of deionized water and 500g of sodium hydroxide and place them in a reaction vessel. Stir and react at room temperature for 0.5h. Then, cool the reaction vessel to -5℃ and keep it at that temperature for 4h. After the reaction is complete, wait for the reaction solution to rise to room temperature, filter it, wash the filter cake twice with deionized water, transfer it to an oven at 40℃ and dry it to constant weight to obtain pretreated chitosan.

[0051] Step II: Preparation of modified vulcanization accelerator

[0052] Weigh 130g of pretreated chitosan and 500mL of methanol and place them in a reaction vessel and stir. Add 1800mL of 30wt% carbon disulfide methanol solution dropwise and stir at room temperature for 15min. Heat the reaction vessel to 50℃ and keep it at that temperature for 4h. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter it, wash the filter cake twice with methanol, transfer it to an oven at 40℃ and dry it to constant weight to obtain the modified vulcanization accelerator.

[0053] Example 2

[0054] This embodiment provides a preparation process for a modified vulcanization accelerator, including the following steps:

[0055] Step I: Preparation of pretreated chitosan

[0056] Weigh out 110g of chitosan, 1300mL of deionized water and 550g of sodium hydroxide and place them in a reaction vessel. Stir and react at room temperature for 1 hour. Then, cool the reaction vessel to -3℃ and keep it at that temperature for 5 hours. After the reaction is complete, wait for the reaction solution to rise to room temperature, filter it, wash the filter cake three times with deionized water, transfer it to an oven at 45℃ and dry it to constant weight to obtain pretreated chitosan.

[0057] Step II: Preparation of modified vulcanization accelerator

[0058] Weigh 140g of pretreated chitosan and 600mL of methanol and place them in a reaction vessel and stir. Add 1900mL of 32.5wt% carbon disulfide methanol solution dropwise and stir at room temperature for 22min. Heat the reaction vessel to 55℃ and keep it at that temperature for 5h. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter it, wash the filter cake three times with methanol, transfer it to an oven at 45℃ and dry it to constant weight to obtain the modified vulcanization accelerator.

[0059] Example 3

[0060] This embodiment provides a preparation process for a modified vulcanization accelerator, including the following steps:

[0061] Step I: Preparation of pretreated chitosan

[0062] Weigh 120g of chitosan, 1400mL of deionized water and 600g of sodium hydroxide and place them in a reaction vessel. Stir and react at room temperature for 1 hour. Then, cool the reaction vessel to 0℃ and keep it at that temperature for 6 hours. After the reaction is complete, wait for the reaction solution to rise to room temperature, filter it, wash the filter cake 4 times with deionized water, transfer it to an oven at 50℃ and dry it to constant weight to obtain pretreated chitosan.

[0063] Step II: Preparation of modified vulcanization accelerator

[0064] Weigh 150g of pretreated chitosan and 700mL of methanol and place them in a reaction vessel and stir. Add 2000mL of 35wt% carbon disulfide methanol solution dropwise and stir at room temperature for 30min. Heat the reaction vessel to 60℃ and keep it at that temperature for 6h. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter it, wash the filter cake 4 times with methanol, transfer it to an oven at 50℃ and dry it to constant weight to obtain the modified vulcanization accelerator.

[0065] Example 4

[0066] This embodiment provides a process for preparing a polyurethane prepolymer, including the following steps:

[0067] Step ①: Preparation of antibacterial modified diol

[0068] Weigh out 10g of cinnamic acid, 15g of triethanolamine and 0.2g of p-toluenesulfonic acid and place them in a reaction vessel and stir. Heat the reaction vessel to 175℃ and keep it at that temperature for 6 hours. After the reaction is complete, wait for the reaction solution to cool to room temperature, add a saturated salt solution of the same volume as the reaction solution, wash once, and transfer the organic phase to a rotary evaporator at 80℃. Evaporate until no liquid is collected to obtain the antibacterial modified diol.

[0069] Step 2: Preparation of polyurethane prepolymer

[0070] Weigh out 10g of antibacterial modified diol, 40g of polyethylene glycol, 2g of dibutyltin dilaurate, and 800mL of toluene and place them in a reaction vessel under nitrogen atmosphere. Stir the mixture and heat the reaction vessel to 80℃. Add toluene-2,4-diisocyanate at 0.55 times the total molar amount of hydroxyl groups of the antibacterial modified diol and polyethylene glycol. Maintain the reaction temperature for 2 hours. After the reaction is complete, heat the reaction vessel to 110℃ and distill under reduced pressure until no liquid is collected to obtain the polyurethane prepolymer.

[0071] Example 5

[0072] This embodiment provides a process for preparing a polyurethane prepolymer, including the following steps:

[0073] Step ①: Preparation of antibacterial modified diol

[0074] Weigh out 15g of cinnamic acid, 20g of triethanolamine and 0.3g of p-toluenesulfonic acid and place them in a reaction vessel and stir. Heat the reaction vessel to 180℃ and keep it at that temperature for 7 hours. After the reaction is complete, wait for the reaction solution to cool to room temperature, add a saturated salt solution of the same volume as the reaction solution, wash and extract twice, and transfer the organic phase to a rotary evaporator at 85℃. Evaporate until no liquid is collected to obtain the antibacterial modified diol.

[0075] Step 2: Preparation of polyurethane prepolymer

[0076] Weigh out 15g of antibacterial modified diol, 50g of polyethylene glycol, 3g of dibutyltin dilaurate, and 900mL of toluene and place them in a reaction vessel under nitrogen atmosphere. Stir the mixture and heat the reaction vessel to 85℃. Add toluene-2,4-diisocyanate at 0.55 times the total molar amount of hydroxyl groups of the antibacterial modified diol and polyethylene glycol. Maintain the reaction temperature for 3 hours. After the reaction is complete, heat the reaction vessel to 115℃ and distill under reduced pressure until no liquid is collected to obtain the polyurethane prepolymer.

[0077] Example 6

[0078] This embodiment provides a process for preparing a polyurethane prepolymer, including the following steps:

[0079] Step ①: Preparation of antibacterial modified diol

[0080] Weigh out 20g of cinnamic acid, 25g of triethanolamine and 0.4g of p-toluenesulfonic acid and place them in a reaction vessel and stir. Heat the reaction vessel to 185℃ and keep it at that temperature for 8 hours. After the reaction is complete, wait for the reaction solution to cool to room temperature, add a saturated salt solution of the same volume as the reaction solution, wash and extract 3 times, transfer the organic phase to a rotary evaporator at 90℃, and evaporate until no liquid is collected to obtain the antibacterial modified diol.

[0081] Step 2: Preparation of polyurethane prepolymer

[0082] Weigh out 20g of antibacterial modified diol, 60g of polyethylene glycol, 4g of dibutyltin dilaurate, and 1000mL of toluene and place them in a nitrogen-protected reactor. Stir the reactor and heat it to 90℃. Add toluene-2,4-diisocyanate at 0.55 times the total molar amount of hydroxyl groups of the antibacterial modified diol and polyethylene glycol. Keep the reactor at this temperature for 4 hours. After the reaction is complete, heat the reactor to 120℃ and distill under reduced pressure until no liquid is collected to obtain the polyurethane prepolymer.

[0083] Example 7

[0084] This embodiment provides a preparation process for a modified self-lubricating capsule, including the following steps:

[0085] Step (1): Preparation of mixed oil phase

[0086] Weigh out 20g of polydimethylsiloxane, 10g of the polyurethane prepolymer prepared in Example 4 and 250mL of dichloromethane and place them in a reaction vessel. Stir at room temperature for 15min to obtain a mixed oil phase.

[0087] Step 2: Preparation of self-lubricating capsules

[0088] Weigh 1000 mL of deionized water and 5 g of sodium lignosulfonate into a reaction vessel, stir at room temperature for 15 min, slowly add 280 mL of mixed oil phase, heat the reaction vessel to 35 °C, keep the temperature for 2 h, after the reaction is complete, wait for the reaction system to cool to room temperature, filter, wash the filter cake twice with deionized water, transfer it to an oven at 50 °C, dry to constant weight, and obtain self-lubricating capsules.

[0089] Step (3): Preparation of modified self-lubricating capsules

[0090] Weigh 20g of self-lubricating capsules and 2g of dopamine hydrochloride and place them in a reaction vessel and stir. Add Tris buffer to adjust the pH to 8 and react at room temperature for 20h. Add 80mL of 2wt% graphene oxide aqueous solution and react at room temperature for 20h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter, wash the filter cake twice with deionized water, transfer it to an oven at 50℃ and dry it to constant weight to obtain modified self-lubricating capsules.

[0091] Example 8

[0092] This embodiment provides a preparation process for a modified self-lubricating capsule, including the following steps:

[0093] Step (1): Preparation of mixed oil phase

[0094] Weigh out 30g of polydimethylsiloxane, 15g of the polyurethane prepolymer prepared in Example 5 and 275mL of dichloromethane and place them in a reaction vessel. Stir at room temperature for 22min to obtain a mixed oil phase.

[0095] Step 2: Preparation of self-lubricating capsules

[0096] Weigh 1100 mL of deionized water and 10 g of sodium lignosulfonate into a reaction vessel, stir at room temperature for 22 min, slowly add 290 mL of mixed oil phase, heat the reaction vessel to 40 °C, keep the temperature for 3 h, after the reaction is completed, wait for the reaction system to cool to room temperature, filter, wash the filter cake 3 times with deionized water, transfer it to an oven at 55 °C and dry to constant weight to obtain self-lubricating capsules.

[0097] Step (3): Preparation of modified self-lubricating capsules

[0098] Weigh 30g of self-lubricating capsules and 3g of dopamine hydrochloride and place them in a reaction vessel and stir. Add Tris buffer to adjust the pH to 8.2 and react at room temperature for 22h. Add 90mL of 3wt% graphene oxide aqueous solution and react at room temperature for 22h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter, wash the filter cake three times with deionized water, transfer it to an oven at 55℃ and dry it to constant weight to obtain modified self-lubricating capsules.

[0099] Example 9

[0100] This embodiment provides a preparation process for a modified self-lubricating capsule, including the following steps:

[0101] Step (1): Preparation of mixed oil phase

[0102] Weigh out 40g of polydimethylsiloxane, 20g of the polyurethane prepolymer prepared in Example 6 and 300mL of dichloromethane and place them in a reaction vessel. Stir at room temperature for 30min to obtain a mixed oil phase.

[0103] Step 2: Preparation of self-lubricating capsules

[0104] Weigh 1200 mL of deionized water and 15 g of sodium lignosulfonate into a reaction vessel, stir at room temperature for 30 min, slowly add 300 mL of mixed oil phase, heat the reaction vessel to 45 °C, keep the temperature for 4 h, after the reaction is complete, wait for the reaction system to cool to room temperature, filter, wash the filter cake 4 times with deionized water, transfer it to an oven at 60 °C and dry to constant weight to obtain self-lubricating capsules.

[0105] Step (3): Preparation of modified self-lubricating capsules

[0106] Weigh 40g of self-lubricating capsules and 4g of dopamine hydrochloride and place them in a reaction vessel and stir. Add Tris buffer to adjust the pH to 8.5 and react at room temperature for 24h. Add 100mL of 4wt% graphene oxide aqueous solution and react at room temperature for 24h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter, wash the filter cake 4 times with deionized water, transfer it to an oven at 60℃ and dry it to constant weight to obtain modified self-lubricating capsules.

[0107] Example 10

[0108] This embodiment provides a manufacturing process for a low-resistance, easily puncturable disposable isolation plug, including the following steps:

[0109] Step 10: Preparation of compound rubber

[0110] Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], erucamide and dibutyl phthalate were mixed evenly in a mass ratio of 1:2:2 to obtain the excipient, which was then set aside.

[0111] Weigh out the following parts by weight: Add 70 parts of isoprene rubber to a mixer at 45°C and mix for 1 minute. Add 3 parts of the modified self-lubricating capsule prepared in Example 7 and 1 part of the auxiliary material and mix for 3 minutes to obtain the compound.

[0112] Step 10: Prepare disposable isolation plugs

[0113] Weigh out the following parts by weight: Add the compound prepared in step ⒜ to a two-roll mill, add 10 parts of the modified vulcanization accelerator prepared in Example 1 and 2 parts of sulfur, cut the rubber alternately from left to right 3 times each, pass through a thin mill 10 times, and cure for 10 hours. After curing, cut the cured rubber into slices and place them into a mold that has been preheated to 80°C. Transfer the mold to a hot press for vulcanization, set the temperature to 150°C, the pressure to 15 MPa, and the time to 10 minutes. Cool to obtain a disposable isolation plug.

[0114] Example 11

[0115] This embodiment provides a manufacturing process for a low-resistance, easily puncturable disposable isolation plug, including the following steps:

[0116] Step 10: Preparation of compound rubber

[0117] Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], erucamide and dibutyl phthalate were mixed evenly in a mass ratio of 1:2:2 to obtain the excipient, which was then set aside.

[0118] Weigh out the following parts by weight: Add 75 parts of isoprene rubber to a mixer at 50°C and mix for 2 minutes. Add 4 parts of the modified self-lubricating capsule prepared in Example 8 and 2 parts of auxiliary materials and mix for 4 minutes to obtain the compound.

[0119] Step 10: Prepare disposable isolation plugs

[0120] Weigh out the following by weight: Add the compound prepared in step ⒜ to a two-roll mill, add 12.5 parts of the modified vulcanization accelerator prepared in Example 2 and 2.5 parts of sulfur, cut the rubber alternately from left to right 3 times each, pass through a thin mill 10 times, and cure for 11 hours. After curing, cut the cured rubber into slices and place them into a mold that has been preheated to 90°C. Transfer the slices to a hot press molding machine for vulcanization. Set the temperature to 155°C, the pressure to 17 MPa, and the time to 12 minutes. Cool to obtain a disposable isolation plug.

[0121] Example 12

[0122] This embodiment provides a manufacturing process for a low-resistance, easily puncturable disposable isolation plug, including the following steps:

[0123] Step 10: Preparation of compound rubber

[0124] Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], erucamide and dibutyl phthalate were mixed evenly in a mass ratio of 1:2:2 to obtain the excipient, which was then set aside.

[0125] Weigh out the following parts by weight: Add 80 parts of isoprene rubber to a mixer at 55°C and mix for 3 minutes. Add 5 parts of the modified self-lubricating capsule prepared in Example 9 and 3 parts of the auxiliary materials and mix for 5 minutes to obtain the compound.

[0126] Step 10: Prepare disposable isolation plugs

[0127] Weigh out the following parts by weight: Add the compound prepared in step ⒜ to a two-roll mill, add 15 parts of the modified vulcanization accelerator prepared in Example 3 and 3 parts of sulfur, cut the rubber alternately from left to right 3 times each, pass through a thin mill 10 times, and cure for 12 hours. After curing, cut the cured rubber into slices and place them into a mold that has been preheated to 100°C. Transfer the mold to a hot press for vulcanization, set the temperature to 160°C, the pressure to 20 MPa, and the time to 15 minutes. Cool to obtain a disposable isolation plug.

[0128] Comparative Example 1

[0129] The difference between this comparative example and Example 12 is that the modified vulcanization accelerator is omitted in step ⒝ when preparing the disposable isolation plug.

[0130] Comparative Example 2

[0131] The difference between this comparative example and Example 12 is that the addition of antibacterial modified diol is omitted in step ② when preparing the polyurethane prepolymer.

[0132] Comparative Example 3

[0133] The difference between this comparative example and Example 12 is that, in step ⒜ when preparing the compound, the modified self-lubricating capsule is replaced with an equal amount of self-lubricating capsule.

[0134] Performance testing:

[0135] The tensile strength, self-sealing properties, and 20% constant compression set (70±2℃, 72h) of the disposable isolation plugs prepared in Examples 10-12 and Comparative Examples 1-3 were tested in accordance with the standard HG / T 2948-1988 "Medical Infusion Rubber Bottle Stoppers".

[0136] The maximum puncture resistance of the disposable isolation plugs prepared in Examples 10-12 and Comparative Examples 1-3 was tested in accordance with standard YBB00322004-2015 "Test Method for Puncture Force of Rubber Stoppers and Gaskets for Injection".

[0137] The visible puncture debris after every ten punctures of the disposable isolation plugs prepared in Examples 10-12 and Comparative Examples 1-3 was tested according to standard YBB00332004-2015 "Test Method for Puncture Debris of Rubber Stoppers and Gaskets for Injection".

[0138] The antibacterial rate of the disposable isolation plugs prepared in Examples 10-12 and Comparative Examples 1-3 was tested according to the standard GB / T 43722.1-2024 "Determination of antibacterial properties of leather - Part 1: Membrane contact method". The specific data are shown in Table 1.

[0139] Table 1 - Performance Test Data for Each Sample

[0140] Project Group Example 10 Example 11 Example 12 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile strength / MPa 11.2 11.3 11.2 8.1 10.7 7.5 Self-sealing No dripping No dripping No dripping There is a leak No dripping No dripping 20% constant compression set / % 23.79 23.65 23.74 29.65 24.15 30.57 Maximum resistance / N 4.7 4.5 4.6 5.1 4.8 7.8 Visible puncture debris / piece 0 0 0 1 0 2 Antibacterial rate / % 99.43 99.48 99.36 97.58 57.98 84.43

[0141] Data Analysis:

[0142] Comparative analysis of the data in Table 1 reveals that the disposable isolation plug prepared by this invention has a tensile strength of 11.3 MPa, no dripping, a 20% constant compression set permanent deformation of 23.65%, a maximum resistance of 4.5 N, and zero visible puncture debris after every ten punctures, while also exhibiting an antibacterial rate of 99.48%. All of these data are superior to the comparative example.

[0143] This invention uses polydimethylsiloxane as the core material and polyurethane prepolymer as the wall material. A self-lubricating capsule is obtained through emulsification, coating, and curing. A dopamine / graphene oxide coating is introduced on the outer layer to obtain a modified self-lubricating capsule, improving its stability and interfacial compatibility with the rubber matrix. The modified vulcanization accelerator is obtained by reacting organic acids with polyols or amino-containing compounds, giving the system a milder and more uniform crosslinking behavior. Subsequently, isoprene rubber, the modified self-lubricating capsule, and excipients are added to a mixer for plasticizing and dispersion. After sheeting and cooling, the modified vulcanization accelerator and sulfur are added sequentially at a lower temperature on an open mill. After uniform mixing, the mixture is extruded or molded to obtain a disposable isolation plug with low puncture force, low chipping, and good self-sealing performance.

[0144] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A low-resistance, easily puncturable disposable isolation plug, characterized in that, It comprises the following components by weight: 70-80 parts isoprene rubber, 10-15 parts modified vulcanization accelerator, 3-5 parts modified self-lubricating capsule, 2-3 parts sulfur and 1-3 parts excipients; The modified self-lubricating capsule is prepared by the following steps: A1. Place polydimethylsiloxane, polyurethane prepolymer and dichloromethane in a reaction vessel and stir at room temperature for 15-30 min to obtain a mixed oil phase; A2. Place deionized water and sodium lignosulfonate in a reaction vessel, stir at room temperature for 15-30 minutes, slowly add the mixed oil phase, heat the reaction vessel to 35-45℃, keep the reaction at this temperature for 2-4 hours, and then process to obtain self-lubricating capsules. A3. Place the self-lubricating capsules and dopamine hydrochloride in a reaction vessel and stir. Add Tris buffer to adjust the pH to 8-8.5 and react at room temperature for 20-24 hours. Add graphene oxide aqueous solution dropwise and react at room temperature for 20-24 hours. Post-process to obtain the modified self-lubricating capsules.

2. The low-resistance, easily puncturable disposable isolation plug according to claim 1, characterized in that, In step A1, the ratio of polydimethylsiloxane, polyurethane prepolymer, and dichloromethane is 2-4 g: 1-2 g: 25-30 mL; in step A2, the ratio of deionized water, sodium lignosulfonate, and mixed oil phase is 100-120 mL: 0.5-1.5 g: 28-30 mL; in step A3, the ratio of self-lubricating capsule, dopamine hydrochloride, and graphene oxide aqueous solution is 2-4 g: 0.2-0.4 g: 8-10 mL, and the concentration of graphene oxide aqueous solution is 2-4 wt%.

3. The low-resistance, easily puncturable disposable isolation plug according to claim 1, characterized in that, The polyurethane prepolymer is prepared by the following steps: B1. Cinnamic acid, triethanolamine and p-toluenesulfonic acid are placed in a reaction vessel and stirred. The reaction vessel is heated to 175-185℃ and kept at this temperature for 6-8 hours. The antibacterial modified diol is obtained after post-treatment. B2. Antibacterial modified diol, polyethylene glycol, dibutyltin dilaurate and toluene are placed in a reaction vessel under nitrogen atmosphere and stirred. The reaction vessel is heated to 80-90℃, toluene-2,4-diisocyanate is added, and the reaction is maintained at this temperature for 2-4 hours. The polyurethane prepolymer is then obtained after post-treatment.

4. The low-resistance, easily puncturable disposable isolation plug according to claim 3, characterized in that, In step B1, the weight ratio of cinnamic acid, triethanolamine, and p-toluenesulfonic acid is 1-2:1.5-2.5:0.02-0.04; in step B2, the ratio of antibacterial modified diol, polyethylene glycol, dibutyltin dilaurate, and toluene is 1-2g:4-6g:0.2-0.4g:80-100mL, and the molar amount of toluene-2,4-diisocyanate is 0.55 times the total molar amount of hydroxyl groups in the antibacterial modified diol and polyethylene glycol.

5. The low-resistance, easily puncturable disposable isolation plug according to claim 1, characterized in that, The modified vulcanization accelerator is prepared by the following steps: C1. Chitosan, deionized water and sodium hydroxide are placed in a reaction vessel and stirred. The reaction is carried out at room temperature for 0.5-1 h. The reaction vessel is then cooled to -5-0℃ and kept at this temperature for 4-6 h. The resulting pretreated chitosan is obtained after post-treatment. C2. Place the pretreated chitosan and methanol in a reaction vessel and stir. Add carbon disulfide methanol solution dropwise. Stir at room temperature for 15-30 minutes. Heat the reaction vessel to 50-60℃ and keep it at that temperature for 4-6 hours. The modified vulcanization accelerator is obtained after post-treatment.

6. The low-resistance, easily puncturable disposable isolation plug according to claim 5, characterized in that, In step C1, the ratio of chitosan, deionized water, and sodium hydroxide is 10-12g:120-140mL:50-60g; in step C2, the ratio of pretreated chitosan, methanol, and carbon disulfide methanol solution is 13-15g:50-70mL:180-200mL, and the concentration of carbon disulfide methanol solution is 30-35wt%.

7. A manufacturing process for a low-resistivity, easily puncturable disposable isolation plug as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Add isoprene rubber to a mixer at a temperature of 45-55℃ and mix for 1-3 minutes. Add modified self-lubricating capsules and auxiliary materials and mix for 3-5 minutes to obtain the compound. S2. Add the mixed rubber to a two-roll mill, add the modified vulcanization accelerator and sulfur, cut the rubber alternately from left to right 3 times each, pass through a thin mill 10 times, cure for 10-12 hours, and mold to obtain a disposable isolation plug.

8. The manufacturing process of a low-resistance, easily puncturable disposable isolation plug according to claim 7, characterized in that, In step S1, the auxiliary material is composed of an anti-aging agent, a lubricant, and a plasticizer in a mass ratio of 1:2:2.