WO2023040559A1 - Hydrophilic coating based on acrylic acid polymerization and photocuring, and preparation method therefor - Google Patents

Abstract

The present invention relates to the technical field of material surface treatment, and disclosed are a hydrophilic coating based on acrylic acid polymerization and photocuring, and a preparation method therefor. The preparation method for a hydrophilic coating in the present invention comprises the following steps: (1) immersing a base material in a pre-treating solution, taking the base material out and drying same to obtain a pre-treated base material; (2) uniformly mixing an acrylic acid monomer, a cross-linking agent, a photoinitiator, a hydrophilic macromolecule, glycerol and water to obtain a hydrophilic solution; and (3) immersing the pre-treated base material obtained in step (1) in the hydrophilic solution obtained in step (2), curing the base material under an ultraviolet lamp while immersion, taking the base material out and cleaning same to obtain a hydrophilic coating-containing base material. The hydrophilic coating of the present invention has excellent bonding strength and hydrophilicity, exhibits an ultra-low friction coefficient in a body fluid environment, is simple in process and has low requirements on an environment and a device.

Description

A kind of hydrophilic coating based on acrylic polymerization and photocuring and its preparation method technical field

The invention relates to a hydrophilic coating based on acrylic polymerization and photocuring and a preparation method thereof, belonging to the technical field of material surface treatment.

Background technique

Silicone rubber has good mechanical properties and chemical stability, and has broad application prospects in the field of biomedical devices, such as common medical catheters, electronic gastroscope external coils, and microfluidic devices. However, the hydrophobicity of the silicone rubber material itself limits its application. When an instrument with silicone rubber as the main material comes into contact with human tissue, it will generate greater frictional resistance and cause certain damage to human tissue. The hydrophilic modification of the surface of silicone rubber can effectively improve the hydrophilicity of the material, reduce the frictional resistance between the device and the tissue, and improve the comfort of the patient.

At present, making hydrophobic materials obtain hydrophilic surfaces can be roughly divided into two steps: first, the surface of hydrophobic materials needs to be pretreated to improve the wettability of the material surface; then, the treated surface is coated or grafted with hydrophilic Substances, in order to achieve the purpose of changing the wettability of the material surface; the pretreatment is generally to directly conduct plasma treatment on the surface to obtain short-term hydrophilic properties.

Contents of the invention

[technical problem]

Preparation of hydrophilic coating by deposition method or graft polymer brush method, although a hydrophilic surface can be obtained, there are still some shortcomings. Fragile and easy to damage; the deposition method usually takes a long time to prepare the hydrophilic coating, and the deposited coating is easy to fall off, and the hydrophilicity is poor. Therefore, it is particularly important to find a method for preparing a simple, short-cycle, and effective hydrophilic coating.

[Technical solutions]

In order to solve at least one of the above problems, the present invention provides a method for preparing a hydrophilic coating based on acrylic polymerization and photocuring. The method is to first immerse the initiator solution, and then immerse the sample in the monomer solution and place Curing under ultraviolet rays, and finally washing off the uncrosslinked product can obtain a hydrophilic coating; the hydrophilic coating of the present invention has excellent bonding strength and hydrophilicity, and exhibits an ultra-low coefficient of friction in a body fluid environment , and the process is simple, with low requirements on the environment and equipment.

First object of the present invention is to provide a kind of method for preparing hydrophilic coating, comprises the steps:

(1) immersing the base material in the pretreatment solution, taking it out, and drying it to obtain a pretreated base material;

(2) acrylic monomers, crosslinking agents, photoinitiators, hydrophilic macromolecules, glycerol and water are mixed uniformly to obtain a hydrophilic solution;

(3) Immerse the pretreated substrate obtained in step (1) in the hydrophilic solution of step (2), solidify under an ultraviolet lamp while dipping, take it out, and clean to obtain a substrate containing a hydrophilic coating.

In one embodiment of the present invention, the pretreatment solution described in step (1) is a benzophenone solution, the solvent of the benzophenone solution is absolute ethanol, and the mass concentration is 1%-10%.

In one embodiment of the present invention, the substrate described in step (1) includes RTV-silica gel, polydimethylsiloxane PDMS.

In one embodiment of the present invention, the impregnation in step (1) is at a temperature of 20-30° C. (room temperature) for 2-10 minutes, more preferably at 25° C. for 5 minutes.

In one embodiment of the present invention, the acrylic monomer described in step (2) is one or more of hydroxyethyl methacrylate, acrylamide, and butyl acrylate.

In one embodiment of the present invention, the crosslinking agent in step (2) is N,N'-methylenebisacrylamide.

In one embodiment of the present invention, the photoinitiator described in step (2) is photoinitiator 2959.

In one embodiment of the present invention, the hydrophilic macromolecule described in step (2) is one of polyaspartic acid, xanthan gum, and sodium alginate.

In one embodiment of the present invention, the mass concentrations of acrylic monomers, crosslinking agents, photoinitiators, hydrophilic macromolecules, and glycerol in the hydrophilic solution described in step (2) are 5% to 20%, respectively. %, 0.5% to 2%, 0.1% to 1%, 1% to 10%, 20% to 40%, and the rest is water.

In one embodiment of the present invention, the impregnation in step (3) is at a temperature of 20-30° C. (room temperature) for 10-30 minutes.

In one embodiment of the present invention, the ultraviolet curing described in step (3) is irradiated with a 365nm/100W ultraviolet lamp for 10-30min.

In one embodiment of the present invention, the cleaning described in step (3) is ultrasonic cleaning with ethanol.

The second object of the present invention is the substrate with hydrophilic coating prepared by the method of the present invention.

The third object of the present invention is the application of the substrate containing the hydrophilic coating or the method for preparing the hydrophilic coating described in the present invention in the field of hydrophilic modification of the surface of medical devices.

[beneficial effect]

(1) The hydrophilic coating of the present invention has excellent bonding strength and hydrophilicity, and exhibits an ultra-low coefficient of friction in a body fluid environment, and has a simple process and low requirements on the environment and equipment.

(2) The present invention carries out the mechanism that silicone rubber is modified by hydrophilicity; At first need carry out pretreatment to silicone rubber substrate, silicone rubber substrate is soaked in the organic solvent that contains initiator, utilizes the characteristic that organic solvent can swell silicone rubber, The initiator penetrates into the interior of the silicone rubber to make the surface of the silicone rubber active; then the silicone rubber is immersed in the monomer solution and placed under ultraviolet light for curing for a period of time; wherein the monomer solution includes acrylic acid monomer, Crosslinking agent, initiator and hydrophilic polymer, during the curing process, the initiator that penetrates into the silicone rubber initiates the polymerization of the monomer below the surface of the silicone rubber, while the external initiator initiates the polymerization of the monomer above the surface of the silicone rubber, The polymerized coating and the substrate have overlapping parts in space, which avoids the problem that the coating will fall off due to poor adhesion; finally, it is only necessary to wash off the product that has not cross-linked with the substrate on the surface of the silicone rubber. Can.

(3) The contact angle of the hydrophilic coating prepared by the present invention is lower than 34.29°, the roughness is below 0.74 μm, and the friction coefficient is 0.11-0.44, compared with the original substrate (silicone rubber sheet, the friction coefficient is 2.16) , The coefficient of friction is reduced by 79.63% to 94.91%.

Description of drawings

Fig. 1 is the contact angle test result of the silicone rubber sheet containing hydrophilic coating of embodiment 1.

FIG. 2 is a surface image of the coating of the silicone rubber sheet containing the hydrophilic coating of Example 1. FIG.

Fig. 3 is the friction coefficient test of the silicone rubber sheet containing the hydrophilic coating of embodiment 1.

4 is a surface image of a silicone rubber sheet containing a hydrophilic coating prepared in Comparative Example 5.

Fig. 5 is the surface contact angle of the silicone rubber sheet containing the hydrophilic coating prepared in Comparative Example 6, wherein A is without adding polyaspartic acid; B is adding polyaspartic acid.

Fig. 6 is the surface image of the silicone rubber sheet containing the hydrophilic coating prepared in Comparative Example 7; wherein A is without adding glycerin; B is adding glycerin.

Detailed ways

Preferred embodiments of the present invention are described below, and it should be understood that the embodiments are for better explaining the present invention, and are not intended to limit the present invention.

Test Methods:

Contact angle test:

Deionized water was used as the test liquid, and a contact angle measuring instrument (JC2000CS, China) was used for the test. The test droplet size was 2 μL, and the spreading time was 30 s. Three locations were randomly tested for each sample, and the results were averaged.

Test for coefficient of friction:

The test was carried out with the rotating module of a multifunctional friction and wear testing machine (MFT-5000, USA). A PDMS disc and a 12mm silica gel ball are used as the friction pair, and the coating is prepared on the PDMS disc. The test lubricating medium is pure water, the loading pressure is set to 0.5N, the rotation speed is 60r/min, and the rotation radius is 10mm. Each sample is tested 3 times, and each test is 3min.

Surface topography and roughness test:

White light interference/atomic force dual-mode microscopy (MFP-D, USA) was used to obtain the surface topography images and surface roughness of the coating. Each sample was randomly tested at 3 locations, and the roughness results were averaged.

Example 1

A method for preparing a hydrophilic coating, comprising the steps of:

(1) Place the silicone rubber sheet (PDMS) cut into 10mm×10mm×3mm in absolute ethanol for 5min ultrasonic cleaning and dry to obtain the cleaned silicone rubber sheet;

(2) 0.5g benzophenone was dissolved in 9.5g absolute ethanol to obtain a pretreatment solution; the silicone rubber sheet obtained in step (1) was immersed in the pretreatment solution at room temperature 25°C for 5min, taken out, and dried to obtain Pretreated silicone rubber sheet;

(3) Dissolve 1g hydroxyethyl methacrylate, 0.2g N,N'-methylenebisacrylamide, 0.2g photoinitiator 2959, 0.8g polyaspartic acid and 8g glycerol in 9.8g In deionized water, a hydrophilic solution is obtained;

(4) Place the pretreated silicone rubber sheet obtained in step (2) in the hydrophilic solution of step (3), dip it at 25°C, place it at 10cm under a 365nm/100W UV lamp, and irradiate it for 20min to carry out ultraviolet treatment. Curing: Take it out after curing, remove the residual reaction product on the surface, and then place it in absolute ethanol for ultrasonic cleaning for 5 minutes to obtain a silicone rubber sheet with a hydrophilic coating.

The obtained silicone rubber sheet containing the hydrophilic coating was subjected to a performance test, and the test results are shown in FIG. 1 .

Figures 1 to 3 are performance tests of the silicone rubber sheet containing a hydrophilic coating in Example 1. As can be seen from Figure 1: compared to the hydrophobic substrate silicone rubber sheet (contact angle at 98.39°), the contact angle of the surface of the silicone rubber sheet containing the hydrophilic coating is 34.29°, showing excellent hydrophilic properties ; As can be seen from Figure 2, the coating surface is relatively smooth, and the coating shows a good surface quality; as can be seen from Figure 3, the friction coefficient of the coating surface is as low as 0.11, compared to the larger friction coefficient of PDMS ( 2.16), the coating greatly improves the lubricating properties of the coating surface.

Comparative example 1

In the pretreatment solution of adjusting embodiment 1 step (2), benzophenone is photoinitiator 1173, photoinitiator 2959, omits the glycerol in step (3) simultaneously, and the consumption of water is adjusted to 17.8g, guarantees affinity The total amount of the aqueous solution was 20 g, and the others were consistent with Example 1 to obtain a silicone rubber sheet containing a hydrophilic coating.

Comparative example 2

Omit the benzophenone in the pretreatment solution of embodiment 1 step (2), omit the glycerol in the step (3) simultaneously, the consumption of water is adjusted to 17.8g, guarantees that the total amount of hydrophilic solution is 20g, other and Example 1 was consistent, and a silicone rubber sheet containing a hydrophilic coating was obtained.

The silicon rubber sheet that contains hydrophilic coating that comparative example 1 and 2 obtains carries out performance test, and test result is as follows:

It can be seen from Table 1: when no photoinitiator is added and photoinitiator 2959 is used to treat silicone rubber, the coating cannot adhere to the surface of the substrate, and the coating preparation fails; when photoinitiator 1173 is used to treat silicone rubber, the coating is hydrophilic Poor water resistance; when benzophenone is used, the coating has excellent hydrophilic properties.

Table 1 Effect of different types of pretreatment solutions on the contact angle of the coating

Initiator type Benzophenone No initiator (comparative example 2) was added Photoinitiator 1173 Photoinitiator 2959 Contact angle (°) 8.64 >90 65.00 >90

Comparative example 3

Adjust the photoinitiator 2959 in the embodiment 1 step (3) to be the initiator 1173, omit the glycerol in the step (3) simultaneously, the consumption of water is adjusted to 17.8g, guarantees that the total amount of the hydrophilic solution is 20g, other and Example 1 was consistent, and a silicone rubber sheet containing a hydrophilic coating was obtained.

Comparative example 4

Omit the photoinitiator 2959 in the step (3) of embodiment 1, omit the glycerol in the step (3) simultaneously, the consumption of water is adjusted to 18g, guarantees that the total amount of the hydrophilic solution is 20g, and others are consistent with embodiment 1 , to obtain a silicone rubber sheet containing a hydrophilic coating.

The obtained silicone rubber sheet containing the hydrophilic coating is subjected to a hydrophilic property test, and the test results are shown in Table 2:

As can be seen from Table 2: when no photoinitiator is added to the hydrophilic solution, the monomer cannot be polymerized on the surface of the substrate, and the coating preparation fails; when photoinitiator 1173 is used, the hydrophilicity of the coating surface is not good, When photoinitiator 2959 is used, the coating has excellent hydrophilic properties.

Table 2 Effect of different photoinitiators on the contact angle of the coating

Initiator type Photoinitiator 2959 Photoinitiator 1173 (comparative example 3) No initiator (comparative example 4) was added Contact angle (°) 8.64 52.49 >90

Comparative example 5

Omit the crosslinking agent N,N'-methylenebisacrylamide in the step (3) of Example 1, omit the glycerol in the step (3) simultaneously, adjust the consumption of water to 18g, and ensure that the total amount of the hydrophilic solution is 20g, the others were consistent with Example 1 to obtain a silicone rubber sheet containing a hydrophilic coating.

The resulting surface morphology containing the hydrophilic coating is shown in Figure 4:

It can be seen from Figure 4 that when no crosslinking agent is added, obvious cracks appear on the surface of the coating, the surface of the coating is hard and brittle, and can be easily broken, and the mechanical properties of the coating do not match the substrate.

Comparative example 6

Omit polyaspartic acid in embodiment 1 step (3), omit glycerol in step (3) simultaneously, the consumption of water is adjusted to 18.6g, guarantees that the total amount of hydrophilic solution is 20g, other and embodiment 1 keep Consistently, a silicone rubber sheet containing a hydrophilic coating was obtained.

The obtained silicone rubber sheet containing the hydrophilic coating is carried out to the hydrophilic performance test, and the test results are as shown in Figure 5:

It can be seen from Figure 5 that when no polyaspartic acid was added, the contact angle of the coating was 63.92°, and when polyaspartic acid was added, the contact angle of the coating decreased to 10.29°, indicating that the addition of polyaspartic acid Acids can increase the hydrophilicity of the coating.

Comparative example 7

Glycerol was omitted in the step (3) of Example 1, and the consumption of water was adjusted to 17.8g to ensure that the total amount of the hydrophilic solution was 20g. Others were consistent with Example 1 to obtain a silicone rubber sheet containing a hydrophilic coating.

The silicon rubber sheet that obtains contains hydrophilic coating is carried out surface topography test, and test result is as shown in Figure 6:

It can be seen from Figure 6 that when glycerol is not added, the coating surface presents a uniform rough structure. After adding glycerol, the rough structure of the coating surface disappeared, and the coating surface was smoother, indicating that glycerin can improve the surface quality of the coating to a certain extent.

Example 2

Adjust the consumption of glycerol in embodiment 1 step (3) to be 0,2,4,6,8,10g, adjust the consumption of water simultaneously to be 17.8,15.8,13.8,11.8,9.8,7.8g, guarantee the hydrophilic solution The total amount was 20g, and the others were consistent with Example 1 to obtain a silicone rubber sheet containing a hydrophilic coating.

The obtained silicone rubber sheet containing the hydrophilic coating is tested, and the test results are shown in Table 3 below:

It can be seen from Table 3 that with the increase of glycerol content, the friction coefficient first decreases and then increases, and the friction coefficient is the smallest when the dosage is 8g, which is 0.11; with the increase of glycerol content, the contact angle gradually increases. increases, the roughness gradually decreases.

Table 3 Effect of different glycerol content on coating properties

Glycerol content (g) coefficient of friction Contact angle (°) Roughness (μm) 0 0.86 9.39 2.12 2 0.67 13.95 1.25 4 0.44 17.62 0.74 6 0.31 23.34 0.29 8 (Example 1) 0.11 34.29 0.05 10 0.47 49.08 0.03

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the claims.

Claims (6)

A method for preparing a hydrophilic coating, comprising the steps of: (1) Immerse the base material in the benzophenone solution, take it out, and dry it to obtain a pretreated base material; wherein, the mass concentration of the benzophenone solution is 1% to 10%; the base material is RTV - Silica gel, polydimethylsiloxane PDMS; (2) Mix acrylic monomers, crosslinking agents, photoinitiators, hydrophilic macromolecules, glycerol and water evenly to obtain a hydrophilic solution; wherein, in the hydrophilic solution, acrylic monomers, crosslinking agents, photoinitiators The mass concentrations of agent, hydrophilic macromolecule and glycerol are respectively 5%-20%, 0.5%-2%, 0.1%-1%, 1%-10%, 20-40%, and the rest is water; The initiator is photoinitiator 2959; the crosslinking agent is N,N'-methylenebisacrylamide; the hydrophilic macromolecule is polyaspartic acid; (3) Immerse the pretreated substrate obtained in step (1) in the hydrophilic solution of step (2), solidify under an ultraviolet lamp while dipping, take it out, and clean to obtain a substrate containing a hydrophilic coating. The method according to claim 1, characterized in that, the acrylic monomer described in step (2) is one or more of hydroxyethyl methacrylate, acrylamide, and butyl acrylate. The method according to claim 1 or 2, characterized in that the curing under the ultraviolet lamp described in step (3) is irradiated under a 365nm/100W ultraviolet lamp for 10-30min. A method for preparing a hydrophilic coating, comprising the steps of: (1) Place the PDMS silicone rubber sheet cut into 10mm×10mm×3mm in absolute ethanol for 5min ultrasonic cleaning and dry to obtain the cleaned silicone rubber sheet; (2) 0.5g benzophenone was dissolved in 9.5g absolute ethanol to obtain a pretreatment solution; the silicone rubber sheet obtained in step (1) was immersed in the pretreatment solution at room temperature 25°C for 5min, taken out, and dried to obtain Pretreated silicone rubber sheet; (3) Dissolve 1g hydroxyethyl methacrylate, 0.2g N,N'-methylenebisacrylamide, 0.2g photoinitiator 2959, 0.8g polyaspartic acid and 8g glycerol in 9.8g In deionized water, a hydrophilic solution is obtained; (4) Place the pretreated silicone rubber sheet obtained in step (2) in the hydrophilic solution of step (3), dip it at 25°C, place it at 10cm under a 365nm/100W UV lamp, and irradiate it for 20min to carry out ultraviolet treatment. Curing: Take it out after curing, remove the residual reaction product on the surface, and then place it in absolute ethanol for ultrasonic cleaning for 5 minutes to obtain a silicone rubber sheet with a hydrophilic coating. The substrate containing the hydrophilic coating prepared by the method according to any one of claims 1 to 3. The application of the substrate containing the hydrophilic coating according to claim 5 in the field of hydrophilic modification of the surface of medical devices.

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