Degradable polylactic acid vacuum blood collection tube and preparation process thereof

Abstract

This invention relates to the field of polylactic acid (PLA) materials technology, specifically disclosing a biodegradable PLA vacuum blood collection tube and its preparation process. The preparation process includes the following steps: S1: Take lactic acid, p-hydroxyphenylpropionic acid, polycaprolactone-polyethylene glycol carboxyl group, stannous octoate, p-toluenesulfonic acid monohydrate, and modified hydroxypropionic acid to prepare polycaprolactone-polyethylene glycol carboxyl-modified PLA; S2: Take lactic acid, p-hydroxyphenylpropionic acid, carboxymethyl chitosan, stannous octoate, p-toluenesulfonic acid monohydrate, and modified hydroxypropionic acid to prepare chitosan-modified PLA; S3: Mix polycaprolactone-polyethylene glycol carboxyl-modified PLA, chitosan-modified PLA, and PLA evenly and add them to an extruder, melt-blend, extrude, and granulate to obtain PLA masterbatch; S4: Use PLA masterbatch to prepare vacuum blood collection tubes; Immerse the vacuum blood collection tubes in an antibacterial and anti-wall-attachment treatment solution, remove, wash, and dry to obtain biodegradable PLA vacuum blood collection tubes.

Description

Technical Field

[0001] This invention relates to the field of polylactic acid materials technology, and specifically discloses a biodegradable polylactic acid vacuum blood collection tube and its preparation process. Background Technology

[0002] Vacuum blood collection tubes are commonly used medical devices for blood testing. They consist of a plastic tube, a stopper, and a label holder. The principle is to pre-evacuate the blood collection tube with a cap to different degrees of vacuum. Using the principle of negative pressure, the collection needle automatically and quantitatively collects venous blood samples, making them convenient to use.

[0003] Common vacuum blood collection tubes are typically made of non-degradable plastics, which are environmentally unfriendly. Therefore, the preparation of vacuum blood collection tubes using biodegradable polylactic acid (PLA) has become a research hotspot. PLA has excellent biodegradability, but its poor mechanical properties and antibacterial properties limit its applications. Adding modifying agents to PLA to improve its performance leads to problems such as high cost, slower degradation rate, and poor compatibility. In summary, researching a PLA with good mechanical properties, good antibacterial properties, and good biodegradability, and the vacuum blood collection tubes prepared from it, is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a biodegradable polylactic acid vacuum blood collection tube and its preparation process, so as to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a preparation process for biodegradable polylactic acid vacuum blood collection tubes, comprising the following steps: S1: take lactic acid, p-hydroxyphenylpropionic acid, polycaprolactone polyethylene glycol carboxyl group, stannous octoate, and p-toluenesulfonic acid monohydrate, mix them evenly, heat under reduced pressure at 100~110℃ for 0.5~1h, raise the temperature to 130~140℃, heat for 0.5~1h, raise the temperature to 155~160℃, add modified hydroxypropionic acid, reduce pressure and polymerize at 160~165℃ for 20~24h, post-treatment (add dichloromethane to dissolve the product, dissolve the precipitate in methanol solution, centrifuge to precipitate), purification, and drying to obtain polycaprolactone polyethylene glycol carboxyl group modified polylactic acid;

[0006] S2: Take lactic acid, p-hydroxyphenylpropionic acid, carboxymethyl chitosan, stannous octoate, and p-toluenesulfonic acid monohydrate, mix them evenly, heat under reduced pressure at 100~110℃ for 0.5~1h, raise the temperature to 130~140℃, heat for 0.5~1h, raise the temperature to 155~160℃, add modified hydroxypropionic acid, reduce pressure and polymerize at 160~165℃ for 20~24h, post-treatment (add dichloromethane to dissolve the product, dissolve the precipitate in methanol solution, centrifuge to precipitate), purification, and drying to obtain chitosan modified polylactic acid;

[0007] S3: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly and added to an extruder. The extrusion temperature (from the feeding section to the die) of the extruder is set to 170, 175, 190, 190, 190, and 170℃, respectively. The screw speed is 50 r / min and the screw length-to-diameter ratio is 20:1. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch.

[0008] S4: Polylactic acid masterbatch is injected into the injection molding machine for plasticization. The plasticization temperature is controlled at 250~260℃ and the plasticization time is 1.5~2s. The plasticized raw material is injected into the mold cavity and pressure is applied until the melt at the gate cools and seals. Pressure is maintained and the mold is demolded to obtain vacuum blood collection tubes. The vacuum blood collection tubes are immersed in antibacterial and anti-wall-sticking treatment solution, then removed, washed, and dried to obtain biodegradable polylactic acid vacuum blood collection tubes.

[0009] In a more optimized manner, the polycaprolactone-polyethylene glycol carboxyl-modified polylactic acid comprises the following raw materials, by mass parts: 20-25 parts lactic acid, 3-5 parts p-hydroxyphenylpropionic acid, 6-8 parts polycaprolactone-polyethylene glycol carboxyl group, 0.1-0.2 parts stannous octoate, 0.05-0.1 parts p-toluenesulfonic acid monohydrate, and 2-3 parts modified hydroxypropionic acid;

[0010] The chitosan-modified polylactic acid comprises the following raw materials, by mass parts: 20-25 parts lactic acid, 3-5 parts p-hydroxyphenylpropionic acid, 3-5 parts carboxymethyl chitosan, 0.1-0.2 parts stannous octoate, 0.05-0.1 parts p-toluenesulfonic acid monohydrate, and 2-3 parts modified hydroxypropionic acid.

[0011] In a more optimized manner, the mass ratio of polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid is (2~3):(1~2):(4~5).

[0012] In a more optimized manner, the polyethylene glycol carboxyl group of the polycaprolactone has a molecular weight of 2000-5000 and the polycaprolactone has a molecular weight of 15000-30000.

[0013] In a more optimized configuration, the polyethylene glycol carboxyl group of the polycaprolactone has a molecular weight of 3400 and the polycaprolactone has a molecular weight of 20000.

[0014] In a more optimized manner, the preparation of the modified hydroxypropionic acid includes the following steps: mixing 2,2-dimethylolpropionic acid, 3-bromopropene, sodium carbonate, and tetrahydrofuran evenly, reacting at 50-60°C for 3-5 hours, removing the solvent, and then removing unreacted substances to obtain modified hydroxypropionic acid; wherein the molar ratio of 2,2-dimethylolpropionic acid, 3-bromopropene, and sodium carbonate is 1:(1-1.1):(1-1.1).

[0015] In a more optimized manner, the antibacterial and anti-wall-sticking treatment liquid comprises the following raw materials, by mass parts: 10-15 parts (mercapto)methylsiloxane-dimethylsiloxane copolymer, 80-100 parts water, 2-4 parts polyvinylpyrrolidone, and 5-8 parts modified aloe vera extract.

[0016] In a more optimized manner, the preparation of the modified aloin includes the following steps: taking aloin and 1-thioglycerol, dissolving them in a mixed solvent, adding magnesium sulfate, stirring at 25~30℃ for 20~30h, filtering to remove magnesium sulfate, removing the solvent by vacuum distillation, and then processing, purifying, and drying to obtain the modified aloin.

[0017] More optimally, the molar ratio of aloe vera, 1-thioglycerol, and magnesium sulfate is 1:(1~1.1):(0.15~0.25).

[0018] A more optimized method for treating vacuum blood collection tubes by immersing them in an antibacterial and anti-fouling solution is as follows: immerse the vacuum blood collection tubes in the antibacterial and anti-fouling solution, add 0.1-0.2% (by weight) of photoinitiator to the solution, and irradiate with ultraviolet light for 3-5 minutes at an intensity of 5-10 mW / cm². 2 Remove, wash, and dry to obtain biodegradable polylactic acid vacuum blood collection tubes.

[0019] Compared with the prior art, the beneficial effects achieved by this invention are as follows: Polylactic acid masterbatch is prepared by uniformly mixing polycaprolactone-polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid in a certain mass ratio; wherein the polycaprolactone-polyethylene glycol carboxyl-modified polylactic acid introduces polycaprolactone segments into polylactic acid, improving their compatibility; wherein the molecular weight of polycaprolactone needs to be controlled between 15,000 and 30,000, if it is too small, the improvement in mechanical properties will not be significant, and if it is too large, it will lead to poor compatibility and slower degradation rate; the introduction of carboxyl groups into chitosan-modified polylactic acid... Chitosan-based polylactic acid (PLA) enhances both mechanical properties and antibacterial properties. This invention involves reacting polycaprolactone-polyethylene glycol (PEG) carboxyl groups and carboxymethyl chitosan with lactic acid to prepare PEG-modified PLA and chitosan-modified PLA, respectively. These are then blended with commercially available PLA, exhibiting good compatibility and reducing the influence of steric hindrance on the grafting rate. The final product is a PLA masterbatch with excellent mechanical properties, degradability, and antibacterial properties. Both PEG-modified PLA and chitosan-modified PLA incorporate a certain amount of modified hydroxypropionic acid, introducing double bonds, which facilitates the subsequent reaction.

[0020] Because directly introducing a large amount of antibacterial modifiers into the polylactic acid matrix can lead to decreased mechanical properties due to poor compatibility, or a slower overall degradation rate due to poor degradability, and is also costly, this solution uses polylactic acid masterbatch to prepare vacuum blood collection tubes, which are then further treated by immersing them in an antibacterial and anti-wall-attachment treatment solution. This solution includes (thiol)methylsiloxane-dimethylsiloxane copolymer, polyvinylpyrrolidone, and modified aloe vera extract. Polyvinylpyrrolidone has excellent film-forming and hygroscopic properties, silicone oil improves blood adhesion to the walls, and modified aloe vera extract enhances surface antibacterial ability. The thiol groups contained therein react with the double bonds in the vacuum blood collection tubes prepared from polylactic acid masterbatch under ultraviolet light, enhancing the bonding force between the two and further optimizing performance. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0022] Unless otherwise specified, all the following quantities are parts by weight or percentage by weight.

[0023] Example 1: S1: 2,2-Dimethylolpropionic acid, 3-bromopropene, and sodium carbonate in a molar ratio of 1:1:1 were added to tetrahydrofuran at a mass of 25 times that of 2,2-dimethylolpropionic acid and mixed evenly. The mixture was reacted at 55°C for 4 hours. The solvent was removed, and unreacted substances were removed by post-treatment to obtain modified hydroxypropionic acid.

[0024] S2: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 8 parts of polycaprolactone polyethylene glycol carboxyl group, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 3 parts of modified hydroxypropionic acid, and reduce the pressure at 165℃ for 24h. After processing, purification, and drying, polycaprolactone polyethylene glycol carboxyl group modified polylactic acid is obtained.

[0025] S3: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 4 parts of carboxymethyl chitosan, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 2 parts of modified hydroxypropionic acid, and reduce the pressure and polymerize at 165℃ for 24h. After processing, purification, and drying, chitosan-modified polylactic acid is obtained.

[0026] S4: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly in a mass ratio of 3:1:4 and added to an extruder. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch.

[0027] S5: Take polylactic acid masterbatch and inject it into the injection molding machine for plasticization. The plasticization temperature is controlled at 250℃ and the plasticization time is 2s. Inject the plasticized raw material into the mold cavity and apply pressure until the melt at the gate cools and seals. Hold the pressure for 2s, demold, and obtain a vacuum blood collection tube.

[0028] S6: Take 12 parts of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 100 parts of water, 3 parts of polyvinylpyrrolidone, and 6 parts of modified aloe vera extract, mix them evenly to obtain antibacterial and anti-wall-hanging treatment solution.

[0029] Preparation method of modified aloin: 1 mol aloin and 1 mol 1-thioglycerol were dissolved in a mixed solvent of 25 times the mass of aloin (the mass ratio of tetrahydrofuran to water in the mixed solvent was 1000:1). 0.2 mol magnesium sulfate was added, and the mixture was stirred at 30℃ for 25 h. The magnesium sulfate was removed by filtration, and the solvent was removed by vacuum distillation. After post-treatment, purification and drying, modified aloin was obtained.

[0030] S7: Immerse the vacuum blood collection tube in an antibacterial and anti-fouling treatment solution, add 0.1% (by weight) of photoinitiator to the solution, and irradiate with ultraviolet light for 3 minutes at an intensity of 10 mW / cm². 2 Remove, wash, and dry to obtain biodegradable polylactic acid vacuum blood collection tubes.

[0031] Example 2: S1: 2,2-Dimethylolpropionic acid, 3-bromopropene, and sodium carbonate in a molar ratio of 1:1:1 were added to tetrahydrofuran at a mass of 25 times that of 2,2-dimethylolpropionic acid and mixed evenly. The mixture was reacted at 55°C for 4 hours. The solvent was removed, and unreacted substances were removed by post-treatment to obtain modified hydroxypropionic acid.

[0032] S2: Take 20 parts of lactic acid, 3 parts of p-hydroxyphenylpropionic acid, 6 parts of polycaprolactone polyethylene glycol carboxyl group, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 2 parts of modified hydroxypropionic acid, and reduce the pressure at 165℃ for 24h. After processing, purification, and drying, polycaprolactone polyethylene glycol carboxyl group modified polylactic acid is obtained.

[0033] S3: Take 20 parts of lactic acid, 3 parts of p-hydroxyphenylpropionic acid, 3 parts of carboxymethyl chitosan, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 2 parts of modified hydroxypropionic acid, and reduce the pressure and polymerize at 165℃ for 24h. After processing, purification, and drying, chitosan-modified polylactic acid is obtained.

[0034] S4: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly in a mass ratio of 2:1:4 and added to an extruder. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch.

[0035] S5: Take polylactic acid masterbatch and inject it into the injection molding machine for plasticization. The plasticization temperature is controlled at 250℃ and the plasticization time is 2s. Inject the plasticized raw material into the mold cavity and apply pressure until the melt at the gate cools and seals. Hold the pressure for 2s, demold, and obtain a vacuum blood collection tube.

[0036] S6: Take 10 parts of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 100 parts of water, 4 parts of polyvinylpyrrolidone, and 8 parts of modified aloe vera extract, mix them evenly to obtain antibacterial and anti-wall-hanging treatment solution.

[0037] Preparation method of modified aloin: 1 mol aloin and 1 mol 1-thioglycerol were dissolved in a mixed solvent of 25 times the mass of aloin (the mass ratio of tetrahydrofuran to water in the mixed solvent was 1000:1). 0.2 mol magnesium sulfate was added, and the mixture was stirred at 30℃ for 25 h. The magnesium sulfate was removed by filtration, and the solvent was removed by vacuum distillation. After post-treatment, purification and drying, modified aloin was obtained.

[0038] S7: Immerse the vacuum blood collection tube in an antibacterial and anti-fouling treatment solution, add 0.1% (by weight) of photoinitiator to the solution, and irradiate with ultraviolet light for 3 minutes at an intensity of 10 mW / cm². 2 Remove, wash, and dry to obtain biodegradable polylactic acid vacuum blood collection tubes.

[0039] Example 3: S1: 2,2-Dimethylolpropionic acid, 3-bromopropene, and sodium carbonate in a molar ratio of 1:1:1 were added to tetrahydrofuran at a mass of 25 times that of 2,2-dimethylolpropionic acid and mixed evenly. The mixture was reacted at 55°C for 4 hours. The solvent was removed, and unreacted substances were removed by post-treatment to obtain modified hydroxypropionic acid.

[0040] S2: Take 25 parts of lactic acid, 5 parts of p-hydroxyphenylpropionic acid, 8 parts of polycaprolactone polyethylene glycol carboxyl group, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 3 parts of modified hydroxypropionic acid, and reduce the pressure for 24h at 165℃. After processing, purification, and drying, polycaprolactone polyethylene glycol carboxyl group modified polylactic acid is obtained.

[0041] S3: Take 25 parts of lactic acid, 5 parts of p-hydroxyphenylpropionic acid, 5 parts of carboxymethyl chitosan, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 3 parts of modified hydroxypropionic acid, and reduce the pressure and polymerize at 165℃ for 24h. After processing, purification, and drying, chitosan-modified polylactic acid is obtained.

[0042] S4: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly in a mass ratio of 3:2:5 and added to an extruder. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch.

[0043] S5: Take polylactic acid masterbatch and inject it into the injection molding machine for plasticization. The plasticization temperature is controlled at 250℃ and the plasticization time is 2s. Inject the plasticized raw material into the mold cavity and apply pressure until the melt at the gate cools and seals. Hold the pressure for 2s, demold, and obtain a vacuum blood collection tube.

[0044] S6: Take 15 parts of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 100 parts of water, 2 parts of polyvinylpyrrolidone, and 5 parts of modified aloe vera extract, mix them evenly to obtain an antibacterial and anti-wall-hanging treatment solution.

[0045] Preparation method of modified aloin: 1 mol aloin and 1 mol 1-thioglycerol were dissolved in a mixed solvent of 25 times the mass of aloin (the mass ratio of tetrahydrofuran to water in the mixed solvent was 1000:1). 0.2 mol magnesium sulfate was added, and the mixture was stirred at 30℃ for 25 h. The magnesium sulfate was removed by filtration, and the solvent was removed by vacuum distillation. After post-treatment, purification and drying, modified aloin was obtained.

[0046] S7: Immerse the vacuum blood collection tube in an antibacterial and anti-fouling treatment solution, add 0.1% (by weight) of photoinitiator to the solution, and irradiate with ultraviolet light for 3 minutes at an intensity of 10 mW / cm². 2 Remove, wash, and dry to obtain biodegradable polylactic acid vacuum blood collection tubes.

[0047] Comparative Example 1 (the mass ratio of polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid was changed, and the remaining methods and steps were the same as in Example 1): S1: 2,2-dimethylolpropionic acid, 3-bromopropene, and sodium carbonate in a molar ratio of 1:1:1 were added to tetrahydrofuran at 25 times the mass of 2,2-dimethylolpropionic acid and mixed evenly. The mixture was reacted at 55°C for 4 hours. The solvent was removed, and unreacted substances were removed by post-treatment to obtain modified hydroxypropionic acid.

[0048] S2: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 8 parts of polycaprolactone polyethylene glycol carboxyl group, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 3 parts of modified hydroxypropionic acid, and reduce the pressure at 165℃ for 24h. After processing, purification, and drying, polycaprolactone polyethylene glycol carboxyl group modified polylactic acid is obtained.

[0049] S3: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 4 parts of carboxymethyl chitosan, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 2 parts of modified hydroxypropionic acid, and reduce the pressure and polymerize at 165℃ for 24h. After processing, purification, and drying, chitosan-modified polylactic acid is obtained.

[0050] S4: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly in a mass ratio of 4:2:2 and added to an extruder. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch.

[0051] S5: Take polylactic acid masterbatch and inject it into the injection molding machine for plasticization. The plasticization temperature is controlled at 250℃ and the plasticization time is 2s. Inject the plasticized raw material into the mold cavity and apply pressure until the melt at the gate cools and seals. Hold the pressure for 2s, demold, and obtain a vacuum blood collection tube.

[0052] S6: Take 12 parts of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 100 parts of water, 3 parts of polyvinylpyrrolidone, and 6 parts of modified aloe vera extract, mix them evenly to obtain antibacterial and anti-wall-hanging treatment solution.

[0053] Preparation method of modified aloin: 1 mol aloin and 1 mol 1-thioglycerol were dissolved in a mixed solvent of 25 times the mass of aloin (the mass ratio of tetrahydrofuran to water in the mixed solvent was 1000:1). 0.2 mol magnesium sulfate was added, and the mixture was stirred at 30℃ for 25 h. The magnesium sulfate was removed by filtration, and the solvent was removed by vacuum distillation. After post-treatment, purification and drying, modified aloin was obtained.

[0054] S7: Immerse the vacuum blood collection tube in an antibacterial and anti-fouling treatment solution, add 0.1% (by weight) of photoinitiator to the solution, and irradiate with ultraviolet light for 3 minutes at an intensity of 10 mW / cm². 2 Remove, wash, and dry to obtain biodegradable polylactic acid vacuum blood collection tubes.

[0055] Comparative Example 2 (changing the molecular weight of polyethylene glycol and polycaprolactone in the carboxyl group of polycaprolactone, with polyethylene glycol molecular weight of 3400 and polycaprolactone molecular weight of 40000): S1: 2,2-dimethylolpropionic acid, 3-bromopropene, and sodium carbonate in a molar ratio of 1:1:1 were added to tetrahydrofuran at a mass of 25 times that of 2,2-dimethylolpropionic acid and mixed evenly. The mixture was reacted at 55°C for 4 hours. The solvent was removed, and unreacted substances were removed by post-treatment to obtain modified hydroxypropionic acid.

[0056] S2: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 8 parts of polycaprolactone polyethylene glycol carboxyl group, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 3 parts of modified hydroxypropionic acid, and reduce the pressure at 165℃ for 24h. After processing, purification, and drying, polycaprolactone polyethylene glycol carboxyl group modified polylactic acid is obtained.

[0057] S3: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 4 parts of carboxymethyl chitosan, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 2 parts of modified hydroxypropionic acid, and reduce the pressure and polymerize at 165℃ for 24h. After processing, purification, and drying, chitosan-modified polylactic acid is obtained.

[0058] S4: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly in a mass ratio of 3:1:4 and added to an extruder. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch.

[0059] S5: Take polylactic acid masterbatch and inject it into the injection molding machine for plasticization. The plasticization temperature is controlled at 250℃ and the plasticization time is 2s. Inject the plasticized raw material into the mold cavity and apply pressure until the melt at the gate cools and seals. Hold the pressure for 2s, demold, and obtain a vacuum blood collection tube.

[0060] S6: Take 12 parts of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 100 parts of water, 3 parts of polyvinylpyrrolidone, and 6 parts of modified aloe vera extract, mix them evenly to obtain antibacterial and anti-wall-hanging treatment solution.

[0061] Preparation method of modified aloin: 1 mol aloin and 1 mol 1-thioglycerol were dissolved in a mixed solvent of 25 times the mass of aloin (the mass ratio of tetrahydrofuran to water in the mixed solvent was 1000:1). 0.2 mol magnesium sulfate was added, and the mixture was stirred at 30℃ for 25 h. The magnesium sulfate was removed by filtration, and the solvent was removed by vacuum distillation. After post-treatment, purification and drying, modified aloin was obtained.

[0062] S7: Immerse the vacuum blood collection tube in an antibacterial and anti-fouling treatment solution, add 0.1% (by weight) of photoinitiator to the solution, and irradiate with ultraviolet light for 3 minutes at an intensity of 10 mW / cm². 2 Remove, wash, and dry to obtain biodegradable polylactic acid vacuum blood collection tubes.

[0063] Comparative Example 3 (changing the molecular weight of polyethylene glycol and polycaprolactone in the carboxyl group of polycaprolactone, with polyethylene glycol molecular weight of 3400 and polycaprolactone molecular weight of 10000): S1: 2,2-dimethylolpropionic acid, 3-bromopropene, and sodium carbonate in a molar ratio of 1:1:1 were added to tetrahydrofuran at a mass of 25 times that of 2,2-dimethylolpropionic acid and mixed evenly. The mixture was reacted at 55°C for 4 hours. The solvent was removed, and unreacted substances were removed by post-treatment to obtain modified hydroxypropionic acid.

[0064] S2: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 8 parts of polycaprolactone polyethylene glycol carboxyl group, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 3 parts of modified hydroxypropionic acid, and reduce the pressure at 165℃ for 24h. After processing, purification, and drying, polycaprolactone polyethylene glycol carboxyl group modified polylactic acid is obtained.

[0065] S3: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 4 parts of carboxymethyl chitosan, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 2 parts of modified hydroxypropionic acid, and reduce the pressure and polymerize at 165℃ for 24h. After processing, purification, and drying, chitosan-modified polylactic acid is obtained.

[0066] S4: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly in a mass ratio of 3:1:4 and added to an extruder. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch.

[0067] S5: Take polylactic acid masterbatch and inject it into the injection molding machine for plasticization. The plasticization temperature is controlled at 250℃ and the plasticization time is 2s. Inject the plasticized raw material into the mold cavity and apply pressure until the melt at the gate cools and seals. Hold the pressure for 2s, demold, and obtain a vacuum blood collection tube.

[0068] S6: Take 12 parts of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 100 parts of water, 3 parts of polyvinylpyrrolidone, and 6 parts of modified aloe vera extract, mix them evenly to obtain antibacterial and anti-wall-hanging treatment solution.

[0069] Preparation method of modified aloin: 1 mol aloin and 1 mol 1-thioglycerol were dissolved in a mixed solvent of 25 times the mass of aloin (the mass ratio of tetrahydrofuran to water in the mixed solvent was 1000:1). 0.2 mol magnesium sulfate was added, and the mixture was stirred at 30℃ for 25 h. The magnesium sulfate was removed by filtration, and the solvent was removed by vacuum distillation. After post-treatment, purification and drying, modified aloin was obtained.

[0070] S7: Immerse the vacuum blood collection tube in an antibacterial and anti-fouling treatment solution, add 0.1% (by weight) of photoinitiator to the solution, and irradiate with ultraviolet light for 3 minutes at an intensity of 10 mW / cm². 2 Remove, wash, and dry to obtain biodegradable polylactic acid vacuum blood collection tubes.

[0071] Comparative Example 4 (the formulation of the antibacterial and anti-wall-attachment treatment solution and the preparation method of the biodegradable polylactic acid vacuum blood collection tube were changed, and the remaining methods and steps were the same as in Example 1): S1: 2,2-dimethylolpropionic acid, 3-bromopropene, and sodium carbonate in a molar ratio of 1:1:1 were added to tetrahydrofuran at a mass of 25 times that of 2,2-dimethylolpropionic acid and mixed evenly. The mixture was reacted at 55°C for 4 hours. The solvent was removed, and the unreacted substances were removed by post-treatment to obtain modified hydroxypropionic acid.

[0072] S2: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 8 parts of polycaprolactone polyethylene glycol carboxyl group, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 3 parts of modified hydroxypropionic acid, and reduce the pressure at 165℃ for 24h. After processing, purification, and drying, polycaprolactone polyethylene glycol carboxyl group modified polylactic acid is obtained.

[0073] S3: Take 25 parts of lactic acid, 4 parts of p-hydroxyphenylpropionic acid, 4 parts of carboxymethyl chitosan, 0.1 parts of stannous octoate, and 0.05 parts of p-toluenesulfonic acid monohydrate, mix them evenly, heat at 110℃ under reduced pressure for 0.5h, raise the temperature to 130℃, heat for 1h, raise the temperature to 160℃, add 2 parts of modified hydroxypropionic acid, and reduce the pressure and polymerize at 165℃ for 24h. After processing, purification, and drying, chitosan-modified polylactic acid is obtained.

[0074] S4: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly in a mass ratio of 3:1:4 and added to an extruder. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch.

[0075] S5: Take polylactic acid masterbatch and inject it into the injection molding machine for plasticization. The plasticization temperature is controlled at 250℃ and the plasticization time is 2s. Inject the plasticized raw material into the mold cavity and apply pressure until the melt at the gate cools and seals. Hold the pressure for 2s, demold, and obtain a vacuum blood collection tube.

[0076] S6: Take 12 parts of methylsiloxane-dimethylsiloxane copolymer, 100 parts of water, 3 parts of polyvinylpyrrolidone, and 6 parts of aloe vera extract, mix them evenly to obtain an antibacterial and anti-wall-hanging treatment solution.

[0077] S7: Immerse the vacuum blood collection tube in the antibacterial and anti-wall-sticking treatment solution for 3 minutes, remove it, wash it, and dry it to obtain the biodegradable polylactic acid vacuum blood collection tube.

[0078] Unless otherwise specified, the experimental methods used in the above embodiments are conventional methods; the raw materials used are commercially available unless otherwise specified, and the sources of the raw materials are as follows: 3-bromopropene (CAS: 106-95-6); sodium carbonate (CAS: 497-19-8); tetrahydrofuran (CAS: 109-99-9); 2,2-dimethylolpropionic acid (CAS: 4767-03-7); lactic acid (CAS: 50-21-5); p-hydroxyphenylpropionic acid (CAS: 501-97-3); polycaprolactone polyethylene glycol carboxyl group (Chongqing Yusi Pharmaceutical Technology Co., Ltd.); stannous octoate (CAS: 3 01-10-0); p-Toluenesulfonic acid monohydrate (CAS: 6192-52-5); Carboxymethyl chitosan (S30948, Shanghai Yuanye); Polylactic acid (medical grade, XK6556, Hubei Xinkang Pharmaceutical Chemical Co., Ltd.); (Mercapto)methylsiloxane-dimethylsiloxane copolymer (T22821, Shanghai Yuanye); Polyvinylpyrrolidone (S30268, Shanghai Yuanye); Aloe vera extract (CAS: 8015-61-0); 1-Thioglycerol (CAS: 96-27-5); Magnesium sulfate (CAS: 7487-88-9); Photoinitiator (CAS: 2128-93-0).

[0079] Experiment: (1) Take the polylactic acid masterbatch prepared by the methods of Examples 1-3 and Comparative Examples 1-4, and test its tensile properties according to GB / T10470-1992; take the biodegradable polylactic acid vacuum blood collection tube prepared by the methods of Examples 1-3 and Comparative Examples 1-4 as samples, place them for 5 days, take a culture dish containing the same type and volume of beef extract agar medium, insert the sample completely (outer surface inserted) into the beef extract agar medium, and incubate in a constant temperature incubator at 37℃ for 4 days, and count the average number of colonies in the culture medium of the group; the results are shown in the table below;

[0080]

[0081] Conclusions: In Comparative Example 1, the mass ratio of polycaprolactone-modified polyethylene glycol (PEG) carboxyl-modified polylactic acid (PLA), chitosan-modified PLA, and PLA was changed. The addition of PEG carboxyl-modified PLA was relatively large, leading to a decrease in performance due to compatibility issues. In Comparative Examples 2 and 3, the molecular weight of polycaprolactone in the PEG carboxyl group was changed, and the performance was not as good as in the example. Therefore, the selection of the PEG carboxyl group is of great importance. In Comparative Example 4, the antibacterial and anti-wall-attachment treatment solution formulation and the preparation method of the biodegradable PLA vacuum blood collection tube were changed, resulting in a significant decrease in antibacterial performance.

[0082] (2) Take the polylactic acid masterbatch prepared in Example 1 and test its weight loss rate over 90 days according to GB / T20197-2006; take the biodegradable polylactic acid vacuum blood collection tube prepared in Example 1 and observe whether there is blood adhering to the wall.

[0083] Conclusion: The polylactic acid masterbatch prepared in Example 1 had a weight loss rate of 75.3% after 90 days, and its inner wall was smooth with no residue. In summary, the biodegradable polylactic acid vacuum blood collection tube prepared by this invention has good mechanical properties, good antibacterial properties, and is easily degradable.

[0084] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A preparation process for biodegradable polylactic acid vacuum blood collection tubes, characterized in that: Includes the following steps: S1: Take lactic acid, p-hydroxyphenylpropionic acid, polycaprolactone polyethylene glycol carboxyl group, stannous octoate, and p-toluenesulfonic acid monohydrate, mix them evenly, heat under reduced pressure at 100~110℃ for 0.5~1h, raise the temperature to 130~140℃, heat for 0.5~1h, raise the temperature to 155~160℃, add modified hydroxypropionic acid, reduce the pressure and polymerize at 160~165℃ for 20~24h, then process, purify, and dry to obtain polycaprolactone polyethylene glycol carboxyl modified polylactic acid; S2: Take lactic acid, p-hydroxyphenylpropionic acid, carboxymethyl chitosan, stannous octoate, and p-toluenesulfonic acid monohydrate, mix them evenly, heat under reduced pressure at 100~110℃ for 0.5~1h, raise the temperature to 130~140℃, heat for 0.5~1h, raise the temperature to 155~160℃, add modified hydroxypropionic acid, reduce the pressure and polymerize at 160~165℃ for 20~24h, then process, purify, and dry to obtain chitosan-modified polylactic acid; S3: Polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid are mixed evenly and added to an extruder. The mixture is melt-blended, extruded, and granulated to obtain polylactic acid masterbatch. S4: Take polylactic acid masterbatch and inject it into the injection molding machine for plasticization. Inject the plasticized raw material into the mold cavity and apply pressure until the melt at the gate cools and seals. Hold the pressure and demold to obtain vacuum blood collection tubes. Soak the vacuum blood collection tubes in antibacterial and anti-wall-sticking treatment solution, take them out, wash and dry them to obtain biodegradable polylactic acid vacuum blood collection tubes. The mass ratio of polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid, chitosan-modified polylactic acid, and polylactic acid is (2~3):(1~2):(4~5). In the polycaprolactone-polyethylene glycol carboxyl group, the molecular weight of polyethylene glycol is 2000-5000, and the molecular weight of polycaprolactone is 15000-30000.

2. The preparation process of a biodegradable polylactic acid vacuum blood collection tube according to claim 1, characterized in that: The polycaprolactone-modified polyethylene glycol carboxyl-modified polylactic acid comprises the following raw materials, by weight: 20-25 parts lactic acid, 3-5 parts p-hydroxyphenylpropionic acid, 6-8 parts polycaprolactone-modified polyethylene glycol carboxyl group, 0.1-0.2 parts stannous octoate, 0.05-0.1 parts p-toluenesulfonic acid monohydrate, and 2-3 parts modified hydroxypropionic acid; the chitosan-modified polylactic acid comprises the following raw materials, by weight: 20-25 parts lactic acid, 3-5 parts p-hydroxyphenylpropionic acid, 3-5 parts carboxymethyl chitosan, 0.1-0.2 parts stannous octoate, 0.05-0.1 parts p-toluenesulfonic acid monohydrate, and 2-3 parts modified hydroxypropionic acid.

3. The preparation process of a biodegradable polylactic acid vacuum blood collection tube according to claim 1, characterized in that: The preparation of the modified hydroxypropionic acid includes the following steps: 2,2-Dimethylolpropionic acid, 3-bromopropene, sodium carbonate, and tetrahydrofuran are mixed evenly and reacted at 50-60℃ for 3-5 hours. The solvent is removed and the mixture is then post-treated to obtain modified hydroxypropionic acid. The molar ratio of 2,2-dimethylolpropionic acid, 3-bromopropene, and sodium carbonate is 1:(1-1.1):(1-1.1).

4. The preparation process of a biodegradable polylactic acid vacuum blood collection tube according to claim 1, characterized in that: The antibacterial and anti-fouling treatment solution comprises the following raw materials, by mass: 10-15 parts (mercapto)methylsiloxane-dimethylsiloxane copolymer, 80-100 parts water, 2-4 parts polyvinylpyrrolidone, and 5-8 parts modified aloe vera extract.

5. The preparation process of a biodegradable polylactic acid vacuum blood collection tube according to claim 4, characterized in that: The preparation of the modified aloin includes the following steps: taking aloin and 1-thioglycerol, dissolving them in a mixed solvent, adding magnesium sulfate, stirring at 25~30℃ for 20~30h, filtering to remove magnesium sulfate, removing the solvent by vacuum distillation, and then processing, purifying, and drying to obtain the modified aloin.

6. The preparation process of a biodegradable polylactic acid vacuum blood collection tube according to claim 5, characterized in that: The molar ratio of aloe vera, 1-thioglycerol, and magnesium sulfate is 1:(1~1.1):(0.15~0.25).

7. The preparation process of a biodegradable polylactic acid vacuum blood collection tube according to claim 1, characterized in that: The specific steps for treating vacuum blood collection tubes by immersing them in an antibacterial and anti-fouling solution are as follows: Immerse the vacuum blood collection tubes in the antibacterial and anti-fouling solution, add 0.1-0.2% (by weight) of photoinitiator to the solution, and irradiate with ultraviolet light for 3-5 minutes at a light intensity of 5-10 mW / cm². 2 Remove, wash, and dry to obtain biodegradable polylactic acid vacuum blood collection tubes.

8. The biodegradable polylactic acid vacuum blood collection tube prepared by the preparation process of the biodegradable polylactic acid vacuum blood collection tube according to any one of claims 1 to 7.

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