A method for producing superlubricant coatings by "direct seeding"

Abstract

The application provides a method for preparing an ultralubricating coating by a "in situ transplanting method", which coats a natural rubber medical catheter with a synthetic polyisoprene solution. Since the synthetic polyisoprene has the same composition as the natural rubber, the interface of the two is firmly combined and the coating does not fall off. An azo initiator opens the double bond in the polyisoprene molecule under ultraviolet light irradiation, and further initiates the polymerization of a vinyl pyrrolidone monomer, so that polyvinyl pyrrolidone side chain molecular brushes grow on the polyisoprene molecular chain, like seedlings growing in a field. The polyvinyl pyrrolidone molecular brushes with ultralubricating effect are firmly combined on the surface of the natural rubber medical catheter, and the purpose of ultralubricating and drag reduction is achieved. The method can prevent the allergic reaction caused by trace amounts of protein in the natural rubber, and can effectively increase the lubricity of the natural rubber medical catheter and reduce the surface friction.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of biomedical materials, and particularly relates to a method for preparing an ultralubricating coating by a 'in-situ transplanting method'. BACKGROUND

[0002] In 2021, the global natural rubber production reached 1384.2 million tons. Natural rubber has excellent physical and mechanical properties, good elasticity, and the maximum elongation can reach 1000%, and is the rubber with the best comprehensive performance. It is the most widely used general-purpose rubber and is made into tires, latex gloves, medical catheters and the like.

[0003] Natural rubber is mainly composed of cis-1,4-polyisoprene connected by head-to-tail, and additionally contains 2% to 3% of protein. The medical catheter made of natural rubber has two problems: 1) a small amount of protein can cause allergic reactions in specific groups of people, and 2) the medical catheter has large surface friction, is easy to damage the natural cavity, increases the pain of patients, is not conducive to the operation of doctors, and can also cause certain sequelae, such as urethral stricture and urethral calculus.

[0004] Therefore, developing an ultralubricating coating technology suitable for natural rubber medical catheters can not only shield the allergic reaction of protein, but also play a role in lubrication and drag reduction, and has important clinical application value. SUMMARY

[0005] The application aims to provide a method for preparing an ultralubricating coating by a 'in-situ transplanting method', which can shield the protein in natural rubber, avoid causing allergic reactions, and effectively reduce the surface friction of a medical catheter.

[0006] The application adopts the following technical scheme:

[0007] A method for preparing an ultralubricating coating by a 'in-situ transplanting method', comprising the following steps:

[0008] 1) synthetic polyisoprene is added to a DMF solvent, heated to 60 DEG C to 90 DEG C, stirred for 2 hours to 4 hours, and cooled to room temperature to prepare a synthetic polyisoprene solution A with a concentration of 1% to 10%;

[0009] 2) N2 is introduced into the synthetic polyisoprene solution A, an azo initiator and a vinylpyrrolidone monomer are added, and stirring is performed to prepare a mixed solution B, which is stored in the dark;

[0010] 3) the natural rubber conduit is immersed in the mixed solution B for 5-60s, taken out, irradiated by ultraviolet light for 10-60s, and dried in an oven at 60-100℃, since the synthetic polyisoprene has the same composition as the natural rubber, the interface of the two is firmly combined, and the coating does not fall off, and the trace protein in the natural rubber is shielded, avoiding the allergic reaction caused by the trace protein, and the azo initiator opens the double bond in the polyisoprene molecule under the irradiation of ultraviolet light, further initiating the polymerization of the vinyl pyrrolidone monomer, so that the polyvinyl pyrrolidone side chain molecular brush grows on the polyisoprene molecular chain, like growing seedlings in a piece of land;

[0011] 4) the conduit treated in step 3) is immersed in a 2%-5% sulfur chloride carbon disulfide solution for 5-60s, taken out, and dried in an oven at 40-60℃, achieving the purpose of polyisoprene vulcanization crosslinking, i.e. the super-lubricating coating on the surface of the natural rubber conduit, so that the anti-allergic and super-lubricating medical natural rubber conduit is obtained.

[0012] In the above technical solution, further, the concentration of the vinyl pyrrolidone is 1%-15%.

[0013] Further, the azo initiator is one or several of azobisisobutyronitrile, azobisisoheptyl nitrile, azobisisopentyl nitrile, and azobiscyclohexyl cyanide, and the mass ratio of the azo initiator to the vinyl pyrrolidone is 0.1:100-1.5:100.

[0014] The principle of the application is as follows:

[0015] The surface of the natural rubber is hydrophobic, and it is difficult to directly coat the water-soluble macromolecule with lubricating effect on the surface, and the coating is easy to fall off. The synthetic polyisoprene solution is used to coat the medical conduit of the natural rubber, since the synthetic polyisoprene has the same composition as the natural rubber, the interface of the two is firmly combined, and the coating does not fall off, and the trace protein in the natural rubber is shielded, avoiding the allergic reaction caused by the trace protein. The azo initiator opens the double bond in the polyisoprene molecule under the irradiation of ultraviolet light, further initiating the polymerization of the vinyl pyrrolidone monomer, so that the polyvinyl pyrrolidone side chain molecular brush grows on the polyisoprene molecular chain, like growing seedlings in a piece of land, so that the polyvinyl pyrrolidone molecular brush with super-lubricating effect is firmly combined on the surface of the natural rubber medical conduit, achieving the purpose of super-lubricating and drag reduction.

[0016] The application has the following beneficial effects:

[0017] The trace protein in the natural rubber medical catheter can cause allergic reaction of specific people, and the surface friction of the rubber catheter is large, the natural cavity is easily damaged, the patient's pain is increased, the operation of the doctor is not convenient, and certain sequelae such as urethral stricture and urethral calculus are caused. The application adopts the "in-situ transplanting method" to prepare the super-lubricating coating, which not only solves the problem of protein allergic reaction, but also achieves the purpose of lubrication and drag reduction. The application coats the natural rubber medical catheter with the synthetic polyisoprene solution, because the synthetic polyisoprene and the natural rubber have the same composition, so the interface combination is firm, and the coating falling phenomenon does not occur. The azo initiator opens the double bond in the polyisoprene molecule under ultraviolet light, and further initiates the polymerization reaction of the vinyl pyrrolidone monomer, so that the polyvinyl pyrrolidone side chain molecular brush grows on the polyisoprene molecular chain, like growing seedlings in a piece of land, so that the polyvinyl pyrrolidone molecular brush with super-lubricating effect is firmly combined on the surface of the natural rubber medical catheter, and the problem of easy falling of the hydrophilic super-lubricating coating is solved. The surface friction of the natural rubber medical catheter coated with the super-lubricating coating is less than 0.05N, which can greatly reduce the pain of the patient and improve the convenience of the medical staff operation. DETAILED DESCRIPTION

[0018] The application will be further described below in combination with specific examples.

[0019] Example 1:

[0020] 1) 1g of synthetic polyisoprene was added to 100mL of DMF solvent, heated to 60℃, stirred for 2 hours, and cooled to room temperature to prepare a 1% synthetic polyisoprene solution A;

[0021] 2) N2 was introduced into the solution prepared in step 1), 1mg of azobisisobutyronitrile initiator and 1g of vinyl pyrrolidone monomer were added, and the mixture was stirred to prepare a mixed solution B, which was stored in the dark;

[0022] 3) The natural rubber catheter was immersed in the solution prepared in step 2) for 5s, taken out, irradiated with ultraviolet light for 10s, and dried in a 60℃ oven. Because the synthetic polyisoprene and the natural rubber have the same composition, the interface combination is firm, and the coating falling phenomenon does not occur. The azo initiator opens the double bond in the polyisoprene molecule under ultraviolet light, and further initiates the polymerization reaction of the vinyl pyrrolidone monomer, so that the polyvinyl pyrrolidone side chain molecular brush grows on the polyisoprene molecular chain, like growing seedlings in a piece of land;

[0023] 4) The catheter treated in step 3) is immersed in a 2% sulfur chloride carbon disulfide solution for 5s, taken out, and dried in a 40°C oven to achieve the purpose of polyisoprene vulcanization crosslinking, thus obtaining an anti-allergic, super-lubricating natural rubber medical catheter.

[0024] Example 2:

[0025] 1) 10g of synthetic polyisoprene is added to 100mL of DMF solvent, heated to 90°C, stirred for 4 hours, and cooled to room temperature to prepare a 10% synthetic polyisoprene solution A;

[0026] 2) N2 is introduced into the solution prepared in step 1), 0.225g of azobisisoheptane nitrile initiator and 15g of vinyl pyrrolidone monomer are added, stirred to prepare a mixed solution B, and stored in the dark;

[0027] 3) The natural rubber catheter is immersed in the solution prepared in step 2) for 60s, taken out, and irradiated with ultraviolet light for 60s, and dried in a 100°C oven. Since the synthetic polyisoprene has the same composition as the natural rubber, the interface between the two is firmly bonded and the coating does not fall off. In addition, the trace amount of protein in the natural rubber is shielded, avoiding the allergic reaction caused by the trace amount of protein. The azo initiator opens the double bond in the polyisoprene molecule under ultraviolet light, further initiating the polymerization of the vinyl pyrrolidone monomer, thereby growing polyvinyl pyrrolidone side chain molecular brushes on the polyisoprene molecular chain, like growing seedlings in a field;

[0028] 4) The catheter treated in step 3) is immersed in a 5% sulfur chloride carbon disulfide solution for 60s, taken out, and dried in a 60°C oven to achieve the purpose of polyisoprene vulcanization crosslinking, thus obtaining an anti-allergic, super-lubricating natural rubber medical catheter.

[0029] Example 3:

[0030] 1) 5g of synthetic polyisoprene is added to 100mL of DMF solvent, heated to 75°C, stirred for 3 hours, and cooled to room temperature to prepare a 5% synthetic polyisoprene solution A;

[0031] 2) N2 is introduced into the solution prepared in step 1), 0.05g of azobisisoheptane nitrile, 0.07g of azobiscyclohexyl nitrile initiator, and 10g of vinyl pyrrolidone monomer are added, stirred to prepare a mixed solution B, and stored in the dark;

[0032] 3) The natural rubber catheter is immersed in the solution prepared in step 2) for 30 seconds, taken out, irradiated with ultraviolet light for 30 seconds, and dried in an oven at 80°C. Since the synthetic polyisoprene has the same composition as the natural rubber, the interface between the two is firmly bonded and the coating does not fall off. The trace amount of protein in the natural rubber is shielded, avoiding the allergic reaction caused by the trace amount of protein. The azo initiator is opened under ultraviolet light, opening the double bond in the polyisoprene molecule, further initiating the polymerization of the vinyl pyrrolidone monomer, thereby growing polyvinyl pyrrolidone side chain molecular brushes on the polyisoprene molecular chain, like growing seedlings in a field;

[0033] 4) The catheter treated in step 3) is immersed in a 3% sulfur chloride solution in carbon disulfide for 30 seconds, taken out, and dried in an oven at 50°C. The purpose of polyisoprene vulcanization crosslinking is achieved, i.e. an anti-allergic, super-lubricating natural rubber medical catheter is obtained.

[0034] The surface friction of the natural rubber medical catheter prepared in all the above examples is less than 0.05 N.

Claims

1. A method for preparing a super-lubricating coating using an "in-situ rice transplanting method", characterized in that, The specific steps are as follows: 1) Add the synthetic polyisoprene to DMF solvent, heat to 60℃~90℃, stir for 2 hours~4 hours, cool to room temperature, and obtain a synthetic polyisoprene solution A with a concentration of 1%~10%; 2) Pass N2 into the polyisoprene synthesis solution A, add an azo initiator and vinylpyrrolidone monomer, stir to obtain mixed solution B, and store it in the dark; 3) Immerse the natural rubber tubing in mixed solution B for 5-60 seconds, remove it, irradiate it with ultraviolet light for 10-60 seconds, and dry it in an oven at 60℃-100℃; 4) Immerse the conduit treated in step 3) in a 2% to 5% sulfur chloride carbon disulfide solution for 5 to 60 seconds, remove it, and dry it at 40°C to 60°C to obtain a super-lubricating coating on the surface of the natural rubber conduit.

2. The method for preparing a super-lubricating coating using the "in-situ rice transplanting method" according to claim 1, characterized in that, The concentration of vinylpyrrolidone mentioned in step 2) is 1% to 15%.

3. The method for preparing a super-lubricating coating using the "in-situ rice transplanting method" according to claim 1, characterized in that, The azo initiator mentioned in step 2) is one or more of azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovalerate, and azobiscyclohexylformitrile, and the mass ratio of the azo initiator to vinylpyrrolidone is 0.1:100 to 1.5:100.